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TRAVELLING WORKSHOP ON ENGINEERING
ASPECTS OF VECTOR CONTROL AND
BIOENVIRONMENTAL CONTROL
OF VECTOR BORNE DISEASES
■.
20 - 24 August, 1990
VENUE
Delhi, Hardwar, Haldwani
THE
TRAVELLING
PROGRAMME
NMEP/MRC TENTATIVE
FOR
WORKSHOP
FOR
SENIOR OFFICERS OF KARNATAKA GOVT.
Dates 20 to 24 Augus t z
1990
Aug .
19, 1990:
Delhi .
Bangalore by Air.
Halt in
Arrival
from
of
are being made in Guest
Houses
Arrangement s
the ICMR, NICD and Karnataka Bhawan etc.
Aug .
20, 1990:
9 A.M. to 12.30 P.M. Rriefing Session- Venue:
Madhuva n, Delhi .
Control of malaria and
Bioenvi ronmental
(jointly
by
the MRC/NMEP).
subjects
20,
related
labo ratori es
Visit t o the MRC
Video films
Aug. 21 , 1990:
Field visit
i n Delhi.
10.00 A.M .
12.30 P.M. General
12.30 A.M.
Delhi-92.
1.00 P.M. Lunch, 20 Madhuban,
Di scussion
Departure to Hardwar by A/C bus.
1 .30 A.M.
:
6.00 P.M.
: Arrival Ha rdwa r, Tea etc.
7.00 P.M.
: 3a th in Ganges,
8.30 P.M.
visit t o Har Ki Pauri
Dinner
Arrangements are being made in
Halt i n Hardwar.
BHEL/IDPL/Roorkee
Univeristy etc.
guest house at
Aug.
22, 1 9 90:
field visit to see
A.M.
- 12.00 P.M.
8.00
at
the
BHEL/IDPL
control
work
malaria'
irrigation schemes etc.
12.00 P.M.
1.00 P.M. Lunch
Halt
1.00 P.M.
- Departure to Haldwani.
Nagar University and other guest houses.
8.00 P.M.
Aug .
23, 1990:
the
and
9.00 P.M.
Departure at 7.00 P.M.
i n Pant
Dinner
t o Haldwani.
see
in
Haldwani
and field visit
to
Breakfast
Halt
irrigation malaria and Ranbassa head works.
in Ha I dwani .
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Aug. 24, 1990:
7.00 A.M. Breakfast
8.00 A.M.
10.00 A.M. Field visit & discussions.
Departure to Delhi, Lunch would be
1 1 .00 A.M.
arranged at a suitable place on way to Delhi.
I n Delhi stay in the same guest house a s on Aug.
19, 1990.
Aug. 25, 1990:
Departure to Bangalore.
avai table.
Transport will be made
Notes:
the
One car may also ac company
1.
A/C bus is being arranged.
team.
2.
‘ ; for Tea/Coffee (2 times a
Organisers would make arrangements
special meals request may be
day)
and working lunch.
For •.
made in advance.
3.
house charges and
Please pay towards the guest
availed
during the stay.
etc.
fac i li t i es such as tea
other
4.
Breakfast and dinner would be arranged on
Accounts would be settled on the last day.
sharing
basis.
5.
settlement of per diem etc., would be
Final
Some advance could be drawn.
August.
6.
Literature on various aspects of malaria control
provided during the field visit.
fol lowing
The
arrangements:
would
officers
be
on
24
wou Id
be
made
responsible
for
S h r i S. C . S h a rma, Guest house arrangements. t r ans po rt.
D r . T. Adak
Tea/Lunch, Literature and field visits etc.
Dr. Aruna Srivastava
Commi 11 ee Room etc.
M.
Dua (Hardwar) and Dr.
V.K.
D r.
arrangments related to stay, food.
field visits.
Malhotra (Haldwani) all
S.
technical presentation and
List of participants would be sent separately as soon as it
i s received.
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Workshop for Engineers, Architects, Town
Planners and
Health Administrators on
Preventive and Corrective Aspects of
Mosquitogenic Conditions Created as
Incidental to Engineering
Projects/Works
INTRODUCTION
It has been Increasingly realised that malaria control based on Insecticidal spray approach
may not succeed due to various technical, financial and administrative limitations. The major
ones being vector resistance to insectlcides.necessitating the use of replacement Insecticides
at prohibitive cost, environmental pollution, harmful effects on beneficial fauna etc. The
emergence of drug resistance in P. falciparum is aggravating the situation further.
This has resulted In high malaria transmission in urban, rural and Industrial areas. As for
example 60-70% of all malaria cases in Tamil Nadu are contributed by Madras city alone. In
Vlsakhapatnam district (Andhra Pradesh) Visakhapatnam Steel Plant contributes 80% of all
cases of the district qnd 35-40% of the stale. Similarly, water resource development projects
contribute to malariogenlc potential in a big way. In Nainltal district. Nanak Matha dam
resulted In creation of water logged areas because initially it lacked seepage channels which
had to be laid after the dam had broken down. In Hardwar (U.P.) the 2 Industrial complexes
viz., BHEL and IDPL had high Incidence of malaria which was man made and simple
engineering works correcteo the situation. A similar situation exists in other Industrial belts of
the country such as in Gujarat ano other endemic states.
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Al the same time case studies carried out in Delhi. Bombay, Madras, Goa, Calcutta.and
other towns, and rural areas throughout the country brought out that mosquitogenic potential
was to a great extent related to faulty designing/execution and poor maintenance of
engineering projects belonging to different sectors of economy. All urban areas are under
stress due to influx from rural areas and population explosion, thus bursting at their seams.
Various studies have shown that in India urban areas would expand to account for about 50%
of the total population by the year 2000 AD. Local bodies are unable to cope up with
matching resources and therefore adopt “ad hocism” in providing civic amenities, which are
invariably inadequate. Under mounting pressure of population explosion the departments
connected with housing, road building and water supply etc. draw their plans to meet the
immediate needs but without ascertaining the long term adverse health Impact. Such a
haphazard growth results in increased Incidence of disease and also makes it difficult to
implement any remedial or corrective measures.
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In order to develop an alternative strategy based on the integrated methods of mosquito
control, role of engineers, architects, and town planners was considered crucial. The present
series of workshops organized in the country is an effort to create an awareness .among the
professionals and seek engineering solutions to mosquitogenic problems generated by the
execution of engineering projects/works.
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OBJECTIVES OF THE WORKSHOP
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• To Impart elementary knowledge about the transmission of vector borne diseases, life
history of mosquitoes and their habitats.
• To study the formation of mosquitogenic potential with varied types of engineering
projects In different sectors of economy.
• Familiarisation with engineering design/execution of projects to prevent mosquitogenic
potential at the design stage and thereafter.
• Field visits to study good and bad engineering works In regard to mosquitogenic
potential and recommend corrective measures.
1. DELHI
1.1 Endemicity to vector borne Diseases
Delhi is endemic for malaria recording over twenty five thousand cases annually. In years of heavy
rains and floods these figures far exceed (over 4 lakh cases in 1978). Malaria Is contributed by two
Anopheline species viz.. Anopheles culicifacies and A. stephensi. While the former is a monsoon
associated species & breeds in fresh waler collections on ground, the latter is a container habitat
species & breeds in wells and in all types of domestic storage containers. Delhi is also endemic for
dengue lever, a viral infection transmilled by Acdus aegyph which again breeds in domestic and
peridomeslic situations. Besides malaria &‘-dengue. Delhi is plagued with very heavy population of
pest mosquito, the Culex quinquefasciaius. The species breeds in polluted water & have two peaks
of population first during March-April & other in September-October.
1.2 Contributory Factors
Major sources contributing mosquilogenic potential for various vector species are as follows.
(a) A culicifacies (Vector of Malaria)
(i)
Embankments of river Jumna with faulty slope towards embankment & stagnating rain/flood
water.
(ii)
Large scale excavations in Rajghat complex connected with National memorials and Indra
Prastha (I.P.) stadium.
(iil)
Lack of outfall in the drainage system of Zoological Gardens.
(iv)
Draining of I.P. thermal power water affluent into Khaddar land.
(v)
Excessive mining in and around Jawahar Lal Nehru Universty Campus.
(vi)
Non-dressing of borrowpits and brick kiln fields.
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(b) A stephensi (Vector of malaria)
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(i)
Water supply carriage and its regulatory mechanism l.e. sluice valve chambers.
(il)
Overhead tanks, wells, storage tanks, ornamental tanks, swimming pools, desert coolers etc.
(c) Aedes aegypti (Vector of dengue fever)
(i)
Domes!ic/peri-domestic water storages
(ii)
Tyre dumps
(iii)
PWD junk yards
(iv)
Water coolers/Air conditioners
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(d) Culex quinquefasciatus
(i) Twelve sullage/sewage drains discharging into ’Khaddar land’ of river jumna and its utilization
for wet cultivation.
(ii) Drains of housing complexes v/ithout outfall for sullage/sewage disposal.
(iii) Laying of drains without embedded cunettes particularly under administrative control of flood
control department.
2.
GOA
2.1 Endemicity to vector borne diseases
All these years malaria has been a rural disease in Goa. With the extension of NMEP unit in 1963,
the disease had been very much under control. Incidence of malaria between 1963 to 1974 ranged
between 6- 175 cases per annum. However during 1975/76 the incidence touched record figure of
2012 cases as elsewhere in the country & the cases came down to mere 80 in 1985.
During 1986. malaria established a strong hold in urban areas. The first city to be affected was
Panaji. Malaria figures showed a steep rise in 1986 when 352 cases were recorded in a population of
50,000. The incidence rose to 4416 cases in 1987 & 4302 (upto Aug.)in 1988 thus accounting for
epidemic situation in the capital.
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Besides malaria Goa is also endemic for filariasis and Japanese encephalitis.
2.2 Contributory Factors
(a) A. stephensi (Vector of malaria)
(0
Faulty water carriage system. Impoundment of water in sluice valve chambers at Ultino.
(ii)
Stagnation of water in regulatory chambers on each distiibution line from leakages.
(iii)
Non-mosquito proof Overhead tanks, ground storage tanks and water storage practices in
areas with limited hours or water supply limited hours.
(iv)
Ornamental tanks/swimming pools with faulty design.
(v)
Water storage practices at construction sites.
(b) Culex quinquefasciatus (Vector of filariasis)
(i)
Drains with faulty gradients
(ii)
Non mosquito proof septic tanks
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3. BOMBAY
3 i Endemicity to vector borne diseases
’ jmbay is the only city in the country v.hich is strictly following the policies laid dov.n during
r-’. sh days for malaria control. These policies basically revolve around engineering solutions and
mplemented through a series of stringent bye-laws. Consequently malaria incidence in Bombay
’opolis never exceeds 2,000 cases per year. In recent years it was only during Indo-Pakistan war
' '?65 when the cases crossed these figures, as most of the sealed wells were opened to meet the
...u exigencies. The incidence was brought down by 1971, when all the wells were re-sealed.
Other mosquito borne infection which exists in Bombay is filariasis, however the incidence is more
.n sub-urban Bombay.
3.2 Contributory Factors
(a) A stephensi
A stephensi problem has been adequately contained by stringent legislative measures as follows:
(i)
Wells : Existing wells have been covered with RCC slabs and hermetically sealed.
(ii)
Cisterns: A standard mosquito proof design as formulated by Municipal Corporation of
Greater Bombay nly permitted. No objection certificate from local malaria officer is a pre
requisite for granting water connection.
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(>'i)
Fountains, garden tanks, tubs:
(IV)
Not permitting fountains which holdwater when idle.
(V)
Garden tanxs without bottom flush and not connected to municipal drain are not permitted.
(vi)
Cellars: To be filled upto percolating level of sub-soil water.
(VII)
Construction sites: Buildingdeposit bye-laws enforced to eliminate breeding potential at con
struction sites.
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(b) Cuiex quinquefasciatus
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High populations are encountered in different areas as follows.
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A Ursewered areas
;i)
Septic tanks and aqua privies: Major source for breeding of mosquitoes.
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(II) Surface drains: Breeding facilitated by lack of gradient, obstruction of flow by crossing of ser
vice lines, Improperly laid cross culverts, garbage accumulation, silting and rodent excavatlons.
(ill)
Covered surface drains: Covering of surface drains by cement slabs renders the drains
Inaccessible lor anyantl- larval activities.
(iv)
Natural water courses: Earlier natural waler courses now turned sullage carrying drains breed
profusely because of emergent vegetation, water hyacinth and growth of grasses.
B. Sewered Areas:-
(I)
Surcharged condition of sewage: Surcharged conditions of sewer often leads to stagnation
and conse quent mosquito breeding.
(ii)
Discharge of surcharged sewers into an open storm water drain which encourages breeding.
(iii)
Wet cultivation: Cultivation with sewage water accounts for prolific breeding.
C. Kurla Mahim Creek - Pest mosquito problem
Kurla Mahim Creek over a period of time got narrowed down at its mouth by construction of ap
proaches for rail and road bridges, cause ways, water lines which resumed in lowering the flushing *
' effecj of tidal waves and thus the salinity upstream. Mangrove in the upper part of the creek build up
high density of Culex gelidus a pest mosquito which breeds in waters with very low salinity.
4. MADRAS
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4.1 Endemicity to vector borne diseases
In Tamil Nadu, urban towns together contribute about 70 per cent of total cases reported from
the whole state. Madras city alone contributes major share. Over the last 5 years, on an average
Madras city accounted for 75 to 80 per cent of fever cases reported from urban areas.
Besides malaria, filariasis is also endemic in Madras city. Annual surveys carried out during the
last three years have shown microfilaria rate ranging from 1.2% to 1.7% while the disease rate varied
from 0.2% to 0.3%.
5.
4.2 Contributory tactors
(a) A stephensi
(i)
Chronic scarcity of water has necessitated dependence on wells as principle source of water
supp'y which becomes the primary source of breeding of A. stephensi.
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L * ■ ..fence of non-mosquito proof overhead tanks and ground storage tanks.
(Ul)
I , reused tendency of domestic storage necessitated by Intermittent water supply.
(iv)
S’
(V)
Construction of OHTs in housing colonies without piped water supply which in turn retain rain
ge practices around construction sites for curing purposes.
water due to open design.
Lack of access to OHTs io housing complexes belonging to Housing Board thus making
(vi)
remedial actions difficult.
(b) Culex quinquefasciatus
(0
Adayar River: Adayar river, a sullage carrying river on account of topographical constraints
is a
decaying river at its entrance point into the sea. Retarded flow encou rages growth
of weeds/other
vegetation which permits prolific breeding of culicine mosquitoes.
• However this phenomenon got neutralized by Hushing action of tidal waves upto 4 to 6 Kms.
upstream and the resultant increased salinity kept the river free of breeding. But due to strong
wind action developed under influence of southwest monsoon and northeast monsoon, the
river got blocked with ‘Sand Bar and prevented the flushing action of tidal waves. This
phenomenon leads to build up of very high population of Culex mosquitoes.
(ii)
Abandoned pits dug along coastal areas by inhabitants to retrieve drinking water.
(iii)
Lack of gradient of sullage carrying drains of housing board.
(iv)
Accumulation of sullage in borrow pits/depressions for lack of outfall.
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5. RECOMMENDATIONS & REMEDIAL ACTIONS
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5.1
Administrative (Action by Government of India)
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5.1.1
Statutory Body for Health Clearance : Each town should have "Statutory Body41 for planning
and control of Urbanisation, analogous to "Art Commission" In Delhi. Scope of this body
should be enlarged to include health components which would examine adverse health im
pacts and associated mosquitogenic potential and would suggest essential anti- malaria
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WO4;S.
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j1’2 ilcomprising of experts from NMEP. MAC. Ministry of Educa-
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5.1.3 -Bureau of Indian Standards' can play a leading role in bringing out a “code of practices" on
specifications of essential anti malaria works of Engineering Projects.
5.2 Technical (Remedial solutions to be adopted)
As the breeding habitats of vectors are species specific, hence the recommendations for remedial !
actions are covered species wise. These will be applicable to all urban areas.
5.2.1 A. stephensi and Xecfes aegypti (Vectois gi urban malaria and dengue fever)
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(a) Water supply system (Caniage, storage and Gtoinuuiion;
Problem : Water collections due to leakages In masonary chambers and surface boxes for fire
hydrants, water meter, stop cock, sluice valves, other vaives and hydrants.
t emCd'f ?C'‘°nS: Adequate P'^entlve maintenance measures and continuous monitoring should
be nuated and strictly observed to prevent leakages. Masonary chambers & surface boxes of sluice
a.ves/regulators and the like should be provided with "soakpits" below the base. Wherever site condihons permit dram pipes may be Installed to drain away the leakage water directly
(b) Domestic Storage installations
Problem : (Overhead tanks, Ground storage tanks)
(i)
Non-mosquito proof manhole covers
• (ii)
Manhole covers of removable nature
(i'i)
Improper access for surveillance
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(c) Wells
: O,«m d.«..U -■»
»■-
We,IS
”
”U'“S
b'“I"’a
mosquitoes.
lion pump Should be provided over the well top onns^a
() venlilalion plpe or shart
“C” hmesh sceen „»h botes no. excecdtng . .5 mm as mosd-o
proof terminal.
(0) Conseuctton design ot OoMng sunshndos. pomco a,Kt Boo, g.«^
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mosquitoes.
(e) Cellars and Basements. Lilt pits, Storage for curing
Pmotem .■ Stagnationotv-ate. to. eatingencou.age b.eeding ot mosquitoes.
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Remedial Actions: (I) P.oeislon should beMiXoXn'should be made
in 6 days cycle and if again needed or cu
basemenls where natural drainage is not possible,
of pumping arrangements in li is pice
maintenance system must be evolved to
The water should be pumped in 6 days cycle, v )
p
follow the above procedures.
(f) Fountains, ornamental tanks and swimming pools
: Stagnation ot teste, mt.i.e « «e p.o.d.s ide., bt.^g sen.ces to.mosguim O.eed
ing
botlom Hush oullel and the same be connected to
Remedial Action: Provision should be made for
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the municipal drain.
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5.2.2 A culicifacies (Vector of malaria)
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(a) Embankment of River Jumna (Delhi)
Problem: Slope gradient towards embankment encourage stagnation of rain waler/receding floods
Remedial Actions: (i) Lead for earth required for bund (embankment) should be taken from a dis
tance so that there remains adequate slope towards the water channel (ii) existing faulty embank
ments should be realigned using bulldozer to maintain adequate slope towards water channels.
(b) Outfall of fresh water into khadder land of Jumna (Delhi)
Problem: Storm water from I.G. Stadium and Rajghat complex is pumped into khadder land & spreads
out before joining the water channel and forms ideal breeding site for malaria vectors. The installa
tion of chamber and draining of water through open jointed pipes into river channel as it would
eliminate the problem of water stagnation on permanent basis.
Remedial Action: (i) Storm water from the outfall pipe should be trapped into a chamber and then
drained through open jointed pipes into the water channel. The sandy bed will prevent leakage from
open joints. Exercise to be carried out after monsoon & pipes removed before monsoon period again
io be relald after monsoon.
(c) Thermal Power Station (Delhi)
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Problem : Water at outfall point from fly ash tanks spread over Khadder land & generate
mosquitogenic potential.
Remedial Actions: (i) Water may be drained through removable open jointed drains corresponding
to monsoon & lean period flow of river channels, and (ii) Slurry ash tanks may be deepened and
provided with filter and suction pump at the bottom & water recycled into the plant, a technology as
adopted by BHEL unit at Hardwar, Uttar Pradesh.
(d) Zoological Park (Delhi)
Problem : Water for zoological park is pumped Into borrow pits of rail track between New Delhl-
Nizamuddin Rly. Station.
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• Remedial Action : Water from Zoological Park should be provided with an outfall connected to river
Jumna or the water can be utilized for horticultural purposes in the adjacent sanitary filling areas.
(e) Excavations (Borrow pits, quarry pits etc)
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Problem : Stagnant water generates high breeding potential for malaria mosquitoes.
Remedial Action : An appropriate clause should be incorporated in the agreement making the contme’ors responsible for dressing the excavations so that there is no stagnation and the borrow pits
fird gradient up to the nearest natural drainage system.
f ' ' Culex quinquefasciatus - (Vector of filariasis)
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ugging of River Adayar by Sand bars (Madras)
Fr.
: Due to lack of gradient river gets plugged by sand bar under wind action and generates
hkj.. mosquitogenic potential.
Rc medial Action: (i) Dredging should be carried out periodically at the mouth of the river to maintain
the flow as well as entry of tidal water upstream, (ii) Large sullage carrying drains should be suitab
ly designed with pi oper gradient of adequate capacity to meet the discharge requirements. To meet
the lean period flow, the bed of drain should have embedded with cunette of adequate capacity. The
bed of drain should be provided with a slope towards cunette, to prevent any stagnation at the uppe )
deck (iii) Partially covered drains with cement slabs should be avoided as far as possible from the
maintenance point of view, as it is easier to maintain regular flow in the drains if it is open in com
parison to partially covered drains, and (iv) Deweeding/desilting of drains should be undertaken
regularly throughout the year to maintain adequate flow instead of undertaking such operations only
once in a year - l.e. during monsoon.
6. HARDWAR
6.1 Industrial Malaria
Setting up of heavy industries are always associated with large scale excavations connected with
levelling of land for erection of factory sheds, network of roads for movement of machinary and final
ly movement of migrant labour. Water collections in the excavations, setting up of labour camps
without appropriate means of water supply and their disposal results in high build up of vector popula
tions and local & focal outbreaks of malaria. In Hardwar setting up of a Unit of Bharat Heavy Electri
cal Limited resulted In steep rise in malaria cases under similar circumstances. MRC Hardwar unit
developed alternate technology based upon environmental methods of control to deal with the situa
tion which is briefly summarized below.
6.2 Problems in Bharat Heavy Electricals
(0
Heavy excavations in connection with levelling of sites.
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(ii) Excavations dug by inhabitants of unauthorised labour colonies
(iii)
Lack of drainage at water stand posts.
(rv)
Lack of gradient of storm water drain.
(v)
Disposal of flyash and water affluent of Thermal Power Station.
6.3 Modernised Parallel Upper Ganga Canal
In the excavation areas (at present abandoned) there exists heavy water logging carrying high
mosquitogenic potential.
6.4 Ganga Project on Prevention of Pollution
Sewage affluent from Rishikesh generated high potential for breeding of Culex mosquitoes and
proved a great curse for local population.
6.5 IDPL Factory
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Sewage affluent from IDPL factory generated similar problem in Pashulok area.
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6.6 Solutions Developed by MRC, Hardwar
6.6.1 Bharat Heavy Electrical Premises
CO
Excavations :
Excavations of all magnitude ranging from ponds of labour colony to large depressions are being
filled v.-ith fly ash produced by Thermal Power Unit at BHEl.
(ii)
Water stand Post:
All the water stand posts were re-aligned to permit outfall of waste water to the nearest natural
drains.
(iii)
Storms water Drains
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Storm wator drains and dlsusod comont tanks woro stocked with larvivorous Gambuslajish
(iv) Sluice valve chambers
All such chambers retaining water resulting from*leakage were stocked with Polystyrene beads
(EPS).
(v)
Thermal Power flyashlwater affluent
Disposal of water affluent problem has been solved by adopting a ’. jw technique" which permits
laying down of a suction pump at the bottom of ash settlement bank d the- water is recycled into the
plant without causing any mosquitogenic potential in contrast to Delhi wI iur ? water affluent is recycled
into the river & creates a high mosquitogenic potential. Fly ash is being used as a filling agent within
the BHEL area, which otherwise accounted for Rs. one million/per annum to the Plant for its disposal.
6.6.2 Construction of modernised parallel upper ganga canal
Construction of Parallel Upper Ganga canal designed to carry 370 cusec of water is a long term
project of the Irrigation Dept, of Govt, of U.P. Initial stages of excavation of canal has resulted in largo
scale borrow pits and waler logging which permit heavy breeding of malarial mosquitoes. The fol
lowing short term and long term measures have been adopted.
Short term : The large bodies of water are being stocked with Gambusia affinis to check breeding
during the construction phase of the canal.
Long Term : In long term, canal is unlikely to produce mosquitogenic potential as it is being con
structed adopting a new technology for lining of slopes and bed with LDP (Low density polythene)
film where water table is lower than bed level. Although primary aim is to prevent seepage losses but
incidently it is this seepage water which not omy results in water logging of the area and renders the
soil unsuitable for cultivation, but also creates marshes suitable for breeding of Anopheline
mosquitoes and thus making the area highly malarious.
6.6.3 Ganga projects on prevention of pollution
Before the launching of Ganga Action Plan the entire sewage from Rishikesh (about 6 million
lilre/day) used to produce millions of mosquitoes besides polluting Ganga river. Action Plan env'sages
pumping of whole sewage to Muni Ki RatiJ and Maya Kund, Oxidation ponds. After retaining the water
for 15-21 days depending upon BOD loading the water is recycled for irrigation purposes at Pashulok
farm and by private cultivators at Lakadghat village.
6.6.4 IDPL Factory
IDPL factory industrial waste water was collected in a pond and nearly low lying areas in Pashulok
area and provided high potential for breeding of Culex mosquitoes. MRC unit diverted this water to
main drain downstream & constructed a new drain to carry water for irrigation pur poses thus eliminat
ing this great health hazard.
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7. NA1NITAL
7.1 Rural Malaria - Haldwani/Nanak Matha/Banbasa.Tanak Pur Hydro Electric Project
Being located in the foothills and Terai region of distt. Nainital. the area had gained the notoriety
of "Death Trap” on account of presence of hyper endemic type of malaria With the launching of.
Nf/iEP, malaria was controlled to a very oreat extent and land reclaimed. The area is now considered •’
to be the granary of the country.
However, various developmental activities undertaken in irrigation sector brought in a new poten
tial for breeding of malaria mosquitoes and the area is since then experiencing p<-rs stance of trans
mission.
7.2 Field Visits to Problem Areas
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(i)
Visit to NMEP control unit Rudrapur : The unit follows residual spraying with BHC on API
basis, surveillance & treatment through MPW scheme.
(ii)
Haldwani field station of MRC : The unit looks after a set of 180 villages by an integrated dis
easevectorcontrol (IDVC) approach. Demonstrations arranged at Gandhapur village included
slocking of cattle drinking pits/ponds with Gambusia affinis, filling of excavations holding *
water, and application of EPS beads around biogas plants.
(iii)
Nanak Matha Dam
(iv)
Sarda Canal Head works at Banbasa
(v)
Hydro-electric Project, Tanakpur
r
7.2.1 Problems at Nanak Matha Dam
(0
Water logging resulting from erosion, generated by flushing action forms pockets of stag- .
nant water for mosquito breeding.
(ii)
Perennial seepage of water from dam & also the seepage channels resulting in creation of
marshes for mosquito breeding of A. culiciiacies.
(iii)
Pockets of stagnant pools at shore line due to falling level of waler reservoir.
7.2.2 Problems at Sarda Canal Head Works
Built In 1920-29 and mainly used for irrigation It was previously a malaria endemic zone, but well
managed with environmental methods of control by construction of "anti-malaria drains" which •
passed through ground channels below the main canal back to the river. Severity of the disease Is
reflected by 8,000 deaths due to malaria reported during the entire period of the project.
13 ,
Problems in recent times include (i) lack of maintenance of drainage channels, (ii) lack of funds
- and (iii) lack of intersectoral coordination
7.2.3 Solutions -Nanak Sagar Dam
i
The major problems were in the design process:
(i)
Pitching of rubble opposite flushing gate needs corrective measures in design to prevent soil
erosion and subsequent formation of ditc h
(ii)
Seepage channel needs proper draii i.j ,e up to the nearest natural drain with suitable gradient
without causing formation of ponds in 'is route.
(iii)
Shoreline area should be so aligned that it should not form stagnant pools with the fall of reser
voir level
7.2.4 Solutions - Sarda Canal Head Works
(')
The area should be properly surveyed with regard to the level of sub-soil water at various
points and a general plan for drainage should be prepared and existing drainage system should
(
be suitably augmented.
r
I
(ii)
Existing open drainage system should be replaced by modern technology of sub-surtace
drains as developed by Central Soil and Salinity Research Institute, Karnal (Haryana). Sub
surface drainage inter alia includes perforated corrugated PVC drainage pipes and synthetic
drainage filters. These drains are provided with inspection chambers. Sub-surface drains, be
sides being cost effective with long life dispense with requirement of routine maintenance of
obstruction caused by falling leaves and weed growth in open drains which encourages
mosquito breeding.
i
i
r
i
8. HYDRO ELECTRIC PROJECT - TANAKPUR
Hydro-electric project under construction by National hydro- electric Corporation is situated 25
km upstream of Banbasa. The design includes construction of barrage with 22 bays with afflux Bund .
on both banks. The design includes laying of open surface drains to deal with seepage water both at
the afflux bund and along power line canal.
(
L
F
Since the open drain system is fraught with danger of mosquito breeding in the event of poor main
tenance. project authorities were impressed upon to use modern technology of laying sub-sur
facedrains instead of open drains based on new technology. Equal emphasis was laid on proper dis
posal of seepage water into natural drainage system without creating stagnation en route.
14
I
f
Lr
t
I
.
9.
RECOMMENDATIONS
9.1 Administrative (action by the GOI)
9.1.1
A high level meeting may be convened to examine the adverse health impact of developmenXeasesClS
SeCt°rS eCOn°my ln reSpeC'O' recePtivi>y
vulnerability to vector borne
9.1.2 A committee may be constituted comprising of experts from NMEP, MRC, Ministry of Educa
tion, Universities and IITs to study and formulate course curriculum on mosquito borne dis
ease control (both preventive and corrective) using engineering methods for various levels of
engineering courses.
9.1.3 Considering the serious health hazards associated with engineering projects it is essential
that all projects are scrutinized from health point of view and approved by the competent health
authorities nominated by the GOI. This authority should be involved at all stages from planning to maintenance.
9.1.4 Bureau of Indian Standards can play a leading role in bringing out "a code of practice" on
specifications of Essential Anti- Malaria works of Engineering Projects.
9.2 Technical (to be adopted)
9.2.1
To create general awareness, workshops on malaria control for engineers should be conducted for Senior Engineers in each Stale/U.T.
9.2.2
Engineers appreciated the fact that much of the problems could have been prevented but for
lack of awareness among Engineers and Architects. To meet this challenge, it was recom
mended that a "Manual on Malaria Control for Engineers" should be prepared for distribution
to be implemented by all engineering deptts throughout the country. Similarly a chapter on '
malaria control1 should be introduced in all degree and diploma courses.
"malaria
9.2.3
Realising that rural malaria is largely contributed by untidy irrigation practices, resulting in for
mation of stagnant pools down stream of barrages, earthen dams, canal/river embankments
waterlogging due to seepages, and inadequate drainage etc.it is recommended that emphasis
should be laid on tidy irrigation i.e., use of conduct or lined canals with LDP films, design of
canal gradients and cross sections to ensure atleast 60 cm/sec velocities, use of sub-soil
seepage canals to prevent seepages from dam/ water logged areas to prevent breeding of A
cuhcifacies in fresh waters.
9.2.4
It IS recommended that to prevent breeding of A. stephensi and Aedes aegypti the container
habitat species, domestic storage containers should be rendered mosquito proof. These
should include overhead tanks, ground level storage tanks, and wells. This should be en
sured by stringent bye laws to ensure construction of specified design and to maintain
mosquito proof status thereafter.
9.2.5
For proper drainage of sullage water in urban areas, drains should be suitably designed with
proper gradient of adequate capacity to meet the discharge requirements. To meet the lean
period flow the bed of the drain should have embedded cunette of adequate capacity. The
i
r
■
15
4
bed of dram should be provided with a slope towards cunette. to prevent any stagnation of
water at the upper deck
9.2 6 Covering of drains having regular flow of sullage should be avoided as far as possible from
the maintenance point of view, as it is easier to maintain regular flow in the drains if it is open
in comparison to the covered drains.
9.2.7
O': img/deweeding of drains should be undertaken regularly throughout the year to maintain
ad; quate flow instead of undertaking such operations only once in a year i.e. during t -monsu n period.
9.2.8 It v.as observed that the technique of the disposal of flyash and water affluent from thermal
power plant at Hardwar was a correct method and the same should be adopted at Delhi In
the former case water was recycled into the plant and did not create any mosquitogenic con
ditions Fly ash could be utilized for filling depressions/borrow pits/excavations which otherwise can not be filled by sanitary filling.
9.2.9 It was observed that distinction must be made in the drainage of seepage water from earthen
dams (Nanak Matha) and sub-soil water from waterlogged areas (Sarda Canal). It was recom
mended that while in the former case drainage channels should have proper gradient free of
weed growth & connected to the nearest natural drain. In waterlogged area, recently
eveloped technology based on sub-surface drains using perforated PVC pipes as developed
by Central Soil and Salinity Research Institute. Karnal should be adopted as besides being
cost- effective it does not create any mosquitogenic potential being closed in comparison to
9.2.10 Authorities at Tanakpur Hydro electric Project were impressed upon to follow the new tech
nology of sub-surface seepage drainage in their project area, as it was still at planning stage.
9.2.11' Effective use of larvivorous fish viz. Gambusia affinis or Poecilia reticulata as the case may
be (former m clear water and later in polluted water) should be made as biological control
agent in water bodies which otherwise cannot be drained.
16
(
from Parasitology Today
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222
v.' 3. no 7. 1987
/
/yn/:'/'
/T-VSIrr/?.1:
Community-based Malaria
Control in India
V.P. Sharma
/'■da launched its National Malaria Eradication Programme (NMEP) m 1958. designee
tc interrupt transmission with residual insecticide spraying coupled with chemotherapy
end anti-larval methods m urban areas The strategy produced spectacular results By
1965 malaria was reduced from around 75 mllion cases annually (with 800 000 deaths)
tc about 100 000 cases per year.
Unfortunately, even under the subsequent maintenance phase, malaria began to
resurge in many foci, and in 1976 the NMEP reported 6.4 million parasite positive cases1.
In this article. V.P. Sharma looks at some of the problems faced by the NMEP strategy, and
d scusses the alternative community-based approach now being evaluated m the northwest
ern state ofGujarat
Malaria control in India is carried out by
the National Malaria Eradication Pro
gramme. with costs shared equally
between Central Government and the
State Government Health Departments.
The programme achieved striking suc
cess during the 1960s with a strategy of
residual insecticide spraying supple-
mented by larvicidal measures in urban
areas and chemotherapy to reduce mor
bidity from the disease.
During the 1970s. malaria resurged in
India in a big way, with 6.4 million cases
reported in 1976 (Box I). At this time
the eradication strategy was abandoned
in favour of a revised strategy known as
the modified plan of operation (MPO).
Implemented in 1977, the MPO was
designed to prevent mortality and mor
bidity due to malaria, protect the 'green
revolution' and the industrial areas, and
retain the previous achievements gained
by the NMEP2. The MPO was a vertical.
Box I. Resurgence of Malaria in India
After nearly a decade of successful vector control using residual
organochlorine insecticides, malaria resurged in India during the
1970s, peaking at around 6.4 million reported cases in 1976.
Some authorities suggested that this was mainly due to insec
ticide resistance associated with increased use of agricultural
insecticides in the course of intensified agriculture. However,
critical studies by Sharma and Mehrotra1 revealed that malaria
resurgence in India was not linked to any aspect of intensive agricul
ture, nor was it initially related to the development of insecticide
resistance in the vector species. The studies found that malaria
resurgence was attributable to four main factors:
1 Shortages of DDT throughout the period of resurgence. From 1958
to 1962-3, India received DDT under the US-AID programme,
while local manufacturing capacity was developed. Subsequently,
India purchased about 60% of the annual requirement of 900016000 metric tonnes, with the remainder to be locally manufac
tured. But imports faced delays and financial constraints, while local
production was frequently interrupted. As a result, there was an
annual shortfall of 13-34% of the required quantity.
2 Persistent malaria foci. In 96 spray units (localities designed to
cover I million population) malaria transmission was never inter
rupted. In some, spray rounds were missed due to labour troubles,
floods, drought, or DDT shortages. In others, malaria transmission
continued even after 12-14 years of attack.
3 Urban transmission. Urban areas were not included in the original
National Malaria Eradication Programme. Malaria control in towns
was the responsibility of local authorities who were often ill-equip
ped, under-staffed, inadequately financed and without the necessary
expertise for vector control. Mosquito larvicidal oil was often in
short supply.
4 Poor surveillance. Eradication of malaria would only have been
possible if, after elimination of transmission, surveillance was able
to detect and treat residual and introduced cases. But in many
areas, surveillance teams were not adequately staffed, trained or
organized. Laboratory services were poor with huge backlogs of
slides to be examined, and intervals of up to 4 months between
case detection and treatment.
In their conclusions, Sharma and Mehrotra’ comment on the
false sense of confidence in the early 1960s that malaria was ‘on its
way out’. In ' 963, the Malaria Institute of India was converted to
the National Institute of Communicable Diseases, and even publica
tion of dui famous Indian Journal of Malariology was suspended.
Research on malaria declined, and during the years of resurgence
there was complete lack of information on the vulnerability of dif
ferent regions of the country*. Now however, the Government of
India is spending Rs 2000 million annually on malaria control (approx.
£100 million), and *here is an increasing commitment to enlist
community participation in control activities.
(g)'967. F
PutxaxxYS. Camtxidge 0'69-4758/87^0200
ParanLo-fgy looey, vo. 3. no i. liO/
centrally administered programme, which
Box 2. National Malaria Eradication Programme,
Multi-purpose Worker Scheme
is gradually being replaced by the ‘multiple
purpose worker’ scheme, and the ‘village
health guide’ scheme under the general
health services of the Ministry of Health
and Family Welfare (Box 2).
The revised approach led to some
improvement in malar a transmission,
shown by the gradual decline to around 2
million reported cases in 1983 But since
then,
I’
malaria cases have remained at
about this reported level, and even this is
probably a gross underestimate of the
true incidence3.
The MPO has faced many problems
About 30% of malana cases in Ind a are
due to Plasmodium falciparum4. wh*ch has
become resistant to chloroquine in many
parts of the country5. Alternative treat
India’s National Malaria Eradication Programme (NMEP) was launched in 1958 as a verti
cal. centrally administered system. After initial success, control failures during the 1970s
prompted a revised strategy known as the Modified Plan of Operation (MPO) which had
redefined objectives to control morbidity and mortality due to malaria rather than to
aim for eradication. By 1978 however, following India’s commitment at the Alma Ata
conference to achieve ’Health for All by the year 2000’, the programme adopted a
national directive to integrate anti-malarial operations with the primary health care ser
vices. The Multipurpose Worker (MPW) scheme is the result, which is now being gradu
ally phased in. Under this scheme, each village should have a trained birth attendant, with
about one village health guide per 1000 population. These are assisted by health volun
teers recruited through the local primary health centre. One male and one female mul
tipurpose worker are then in cnargc of areas comprising 5000 people (3000 in difficult
areas), with one supervisor for 4 MPWs. Amongst their tasks, MPWs implement malaria
surveillance and chemotherapy, reporting through their supervisor to the local medical
officer. The MO can respond through a malaria inspector in charge of 44 spray squads per
I million population. Thus, although the organizational structure has changed, the basic
control strategy remains similar.
ment schedules have been implemented
in these areas, but focal studies show a
State Government Department of Health
Directorate of Health Services
considerable increase in faloparum.malana
with fulminating epidemics resulting in
reports of deaths in some areas On the
vector side, ♦here are 9 vector species of
Anopheles in India, with An cuhafacies the
___________ 1___________
I
State Malariologist
(Cross-checking Laboratory)
I
most widely distributed throughout rura1
areas6. This species Las become res stant
to DDT and HCH in most parts of the
country, and is also resistant to maatnon
m the states of Gujarat and Maharashtra
Division of
Rural Health Services
Zonal Malaria Officer
(Entomological)
I_______ I
J
Divisional Health Office
(1 for each 4-5
Districts)
Some of the other vectors arc exoph. c
and avoid contact with sprayed wa’.s
- District
Chief Medical Officer
District Health Officer
District Malaria Officer
But m addition to vector resistance,
the strategy of insecticidal spraying now
faces additional problems due to the
L_____ ______ _
reluctance of villagers to have their
Subdivisional Hospital
(Referal Services)
houses sprayed. The side-benefits of
house-spraying, such as control of bed
bugs
r
and
housed es.
appreciated
no
are
District Hospital
(Referal Services)
longer
by the villagers; indeed,
soon after spraying with DDT the bed
bug nuisance often increases - probably
Assistant Malaria
Officer
Community Health
Officer
Primary Health Centre
(Referal Services)
Medical Officers
(3 in each PHC)
Primary Health Centre
(1 per 30,000
population)
(Malaria Laboratory)
due to the excito-repellent action of
DDT. There is also increasing concern
about environmental contamination with
pesticides, and spraying is not accepted
where there are cottage industries such
some
as bee-keepmg or silk cult '"
areas, the proportion of F
• C CO’S
refusing to have their house
..♦30 has
become very high One co-' ■
I
□
Malaria Inspector
MPW Supervisor
(1 for 4 MPWs)
Spray squads
(44 squads per
1 million population)
Multipurpose Workers
(1 male and 1 female
for 5000 population, or
for 3000 in difficult
areas)
PHC Subcentre
Village Health Guides
(1 for 1000 population)
Trained Birth Attendant
(1 per village)
Health Volunteers
j .•..■rce is
that an increasing numbe’’ o’ c “ • :-^eds
-/'ter -
a^e now sprayed, which can o
productive if it drives th-
away
from the
cattle
r
the
. • s of
she
houses. There are other p .
financial,
log.stic
and
aon r •t-awe
naturefsee Box I), includingd :■ :
as m
obtaming insecticides and e. ■
'
of malpractice with insect1
c . • tea
to agricultural use.
The cost of sp aying opu at
is
alarmingly high. The Government of
India is currently spending aoout Rs 800
Organizauon of the Multipurpose Worker (MPW) scheme including malaria control under
million annually on malaria control alone
the primary health care (PHC) system.
(approx
£40 m liion); this represents
i ri'.ilj! ia erac caton
The pl I.1 - . '
using
•i
rcs'Cu .
components i ' '
k*
vecto'
• : onent - man
•<>:) two asstimp
This Af atcf • ■■
lions ' I) m •
I>;ng would kill
•
; ■ i; life e<pec-
the vcc to
dcvelopme ’
! wou’d allow
•. M>-te. and (2)
drugs woul
pa^astc from
tanc>
-I-
* ;
r-
Z -'"T
spra/s and
thout involve
and ,
men: of tl
a : SSI
de
"• destabiizc two
,J t* ia triar.glc’(i c.
chemotherapy
ocIo a
the i
’
■ ■
■Jana opera-
ados of '-■■■
• I.- r esistance
•
lions b iv
of all three
of the triangle:
.
Fig I To control mosquito breeding in ponds,
larvivorous fish (Aplocheilus sp.) are intro
duced and the margins periodically cleared of
oquouc vegetation
Fig 2 Mosquito breeding in wells and pits can
be controlled by adding expanded polystyrene
beads which form a lasung mat over the sur
face The mat quickly reforms if the surface is
disturbed
Fig 3. School children participate in voluntary
work to fill in borrow prts where rainwater col
lects and mosquitoes can breed
i
physiological resistance of the vectors,
5^'
drug resistance by the parasite, and resis
tance to spraying by man. But it is poss
ible to tackle this three-cornered resis
tance by using integrated bio-environmental control methods.
Bio-environmental Strategy
The
bio-environmental
envisages
strategy
pnmary em.phasis on man
who. in the form o; U.e community,
helps to fight the other two components
- parasite and vector. The agency
responsible for spraying assumes respon
sibility for mobilizing local resources and
social willingness to control transmission.
about 45% of her total health budget,
and is to be matched by a similar amount
from
the State Governments.
effectiveness of these operations quite
questionable7-9.
and applied to manage the environment
to make it inhospitable for vector multi
Many
States find rt difficult to provide the
Instead of spending money on insecti
cides. local technologies are developed
A Crisis waiting for an Alternative
strategy
bongs
matching grants, causing local malaria
plication.
control to be suspended pending the
semi-permanent ecological changes, but.
availability of funds. Yet the epidemiol
ogy of the disease is such that if control
is neglected for a year or two. it may
assume epidemic proportions. But out
This
insecticidal
the
about
bio-
Over the last fev\ year s there seems
to have been no true decline in malaria
transmission even though the Govern
unlike
ment is domg almost everything possible.
therefore assume high importance; elim
spraying,
environmental methocs do not affect
the longevity of mosqur.oes. Two factors
Malaria control in India is m a state of
ination of the parasite from the commu
areas where spraying operations have
crisis waiting for some alternative to
been continuous - making the cost-
emerge.
nity by treatment of parasite-positive
cases, and suppression of vector ^opula-
breaks of malaria have occurred even in
lockif. vol 3. no 7. /*87
tions through rural development. In this
way. control of the disease is not seen as
an end in itself, but represents an entry
point into the rural development pro
cess It is essential that the vector control
activities become an integral part of
community development, so that these
activities will be maintained even when
vccto'' populations are substantially
reduced. If not. people can loose interest
in vecto'' control itself, and become vulnerabe to sudden epiderrvcs through
loss of immjr. t; combined with a few
mtrod /ced malaria cases and sudden
so .,rt of vecto-' populations.
Demonstration in Gujarat
. i
A demonstration and feasibility study
of th.s approach was launched in 1983 in
Nad<ad taluka in the Kheda district of
Gujarat state Malaria is endemic to this
region; Kheda district had the highest
incidence of malaria for several years,
and Nad-ad taluka was the worst
affected area with a h>gh inc dence of fal
ciparum malaria resulting m several
deaths. Mosquito breeding sites were
innumerable, and insecticide spraying
was not producing a tangible reduction in
transmission.
The bio-environmental strategy con-
sisted of seven components:
r
1 Reduction of breeding sites by
minor engineering works
2 Elimination of breeding sites by
physical barriers
3 Biological control of vectors, e.g.
using larvivorous fish
4 Health education
5 Community participation in control
activities
6 Chemotherapy of parasite-positive
cases
7 Environmental improvement and
income generating schemes
Intensive surveillance and prompt treat
ment of cases was the first line of action.
This reduced morbidity and eliminated
mortality from malaria, and also infused
tremendous confidence in the villagers.
Also, elimination of many breeding sites
reduced the mosquito populations so
that villagers felt less mosquito nuisance.
A series of lectures in schools and com
munity centres helped to inform the
communities about our activities, and
encouraged them to help and partici
pate.
All water collection sites that could
support mosquito breeding were sur
veyed and mapped. Simple methods
were used to eliminate mosquito breed
ing. such as turning pots upside down.
covering water receptacles, and filling
borrow pits with soil. Mosqu'to breeding
in ponds was reduced by introducing
guppy fish (Ap/dche/fus sp ) which were
collected locally and bred m abandoned
cement tanks and ponds V2e estimate
that guppies grown in 20 village hatch
enes can produce enough fish fo^ the
whole taluka of 100 villages Vcgetatior
in the ponds is cleared period>caliy to
allow the fish to reach the grassy margins
which are the most common mosquito
breed-r-g : tr'
Wei s tha* wc-e no* used regulady
were ano’?-s'lrw '/ m.osqui*/.breedmg cspecia1 . of ' j • x qumquefr^ciatus and occasiona'iy A' < ji cifacies and
Ar stephor’: h "'-an, of t^ese we intro
duced expanded polystyrene (EPS;
beads which term a lasting mat over the
surface to p-e.ent access by ovipositing
female mosqu toes, and to prevent the
larvae from b eathmg" 1(Fig 2) In
some of the least-used we! s we intro
duced guppies.
For more substantia' tas- s such as filling
in and levelling borrow p ts ano othe”
depressions where wate1’ co'iected. the
community organized vo -ntary labou''
groups (Snram, Dans; (Fig 3). These
groups a^e now equipped with 4 tractors
to help level the land around villages. In
addition to controlling anophelme mos_ qurtoes. the surface drams and pits where
Cx quinquefosc/atus breeds were also
cleaned and emptied. Many are now being
replaced by soak pits.
Income-generating Schemes
It was realized that as the incidence of
malaria and mosquito nuisance went
down, the villagers may loose interest.
Thus to sustain interest and to boost vil
lage economy, schemes of composite
fish culture, social forestry and improved
stoves are being encouraged as part of
village development. Composite fish
culture - rearing edible fish with the
larvivorous fish - has been particularly
successful. In the first year, income gen
erated by edible fish rearing in 8 ponds
was 100 times that earned normally,
even when three ponds dried due to
drought. The culture and sale of edible
fish is now being extended, and could
make the community malaria control
activities completely self-financing.
The social forestry scheme also has a
dual role. Eucalyptus has been planted in
low-lying marshy areas to dry the land
and prevent mosquito breeding. Large
scale
plantations
are also being
developed in unused waste land around
each village. Demand for this has
exceeded the a vailability of young trees,
so vi:'agc.- council-nurseries are being
encouraged which also allow villagers to
plant tmes of their own choice. 3 he tree
:• a' r.r ons will become an important
• ■ ■ J income, and wc' estimate that
• ■ . . ,
earnings from social forestry
r n . egion wi I eventua’ y cover the
• ■ • : other malaria control activities
t .
O' of five
zigma demonstration area
■ / A)covered seven villages with
• - - -:' r " rJr ra^sc of
< -i-./ar success cf the malaria
d'ti/it'es. the project was
■: ’o 14 more vi'ages in 1984
■ ■ bj and a further 79 villages in
-'p'ex C) The total of 100
•
a population of abound
350 CC5 Results m the entre area have
been r” ost encouraging witn a general
imp’-jvement m the environment and
enhanced awareness about malaria and
methods for its control Vector incrimi
nation was not done, but populations of
Ar
the tv.o -suspected vectors
have
cuk/fcices and An stephens
declined to very low levels. Ma ana cases
have dec med m complex A over three
years from 4 I I to 61. m complex B from
143 to 70 over two years, and in com
plex C Mom 906 to 485 in one year. In
contrast, nearby areas under msecticida1
spraying have shown high vector
densities and a r ise m malaria transmis
sion. particularly of P falciparum By
1987. we hope to extend the project to
cover other areas with a total population
of about I mi’lion.
Cost estimates suggest that to control
malaria in the entire rural population of
Kheda district (population 2.7 million) the
cost of using DDT. HCH or malathion
would be Rs 9.2 million. 10 million or
53 7 million respectively (£ I = approx.
Rs 20). This compares with Rs 8.5 million
by bio-environmental methods14. Moreove”. the b'O-envirpnmental anproach has
ma-; of
advantages, espeoa' y m
generating local employment and provid
ing a sustainable economy. Imports are not
required, the strategy is socially acceptable
and can improve the local environment,
and it can also reduce the incidence of
other diseases. They key however, is that
rt addresses malaria within its local social
context, and places disease control
alongside the other priorities of village life.
VP Sharma /s Duerer of the Molana Research
Centre. 22 Sham Nath Marg. Delhi 110054.
India
References
1 Sharma. VP and Mehrotra. KM (1986) Soc
Sc/ Mel 22. 835-845
2 Pattanaya< S and Roy. RG (1980) J Ccmm
06 12. 1-14
Porasn^Dgy Today, vol. 3, no 7, 1987
226
3 National Malana Eradication Programme
(1985) In-depth evaluation report of the modified
plan ofoperation under NMEP, 56 pp.
4 Sharma. G.K. (1984) Proc Indo-UK Workshop
on Malaria, pp. 13-40
5 Sharma, V.P. (1984) Proc. Indo-UK Workshop on
Malaria, pp 169-184
6 Ramachandra Rao. T. (1984) The Anophehnes of
India, Indian Council of Medical Research,
Delhi, 510 pp.
7 Chandrahas, R.K. and Sharma. V.P. (1983) Ind.
J.Malonol 20. 163-166
8 Malhotra. M. S.. Shukla R.P. and Sharma. V.P.
(1985) Ind. J. Malariol 22.57-60
9 Malhorta. M.S., Shukla, RP. and Sharma. V.P.
(1985) Ind. J. Makjriol 22. 123-126
10 Sharma. VP. Sharma. R.C. and Gautam. AS.
(1986)Ind J Malar>o/23.95-117
11 Curtis, C F and Minjas, J. (1985) Paravtol Today
I.p 36
12 Sharma.V.P.(1984)IndJ Malanolll. 115-118
13 Sharma. R.C.. Yadav. R.S. and Sharma. V.P.
(1985) Ind J Molark>I 22. 107-109
14 Sharma. V.P. and Sharma. R.C. (1986) Ind. J.
Malonol 23. 141-145
i
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WORLD HEALTH
ORGANIZATION
REGIONAL OFFICE lui
SOUTH
EAST
ASIA
Workshop on Regional Manpower Requirements
for Urban Malaria/Mosquito Control
Programmes, Hyderabad, India 30 October - 12 November 1981
SEA/MAL.Meet.l2/WP.S
I*
ENGINEERING ASPECTS OF MOSQUITO CONTROL OPERATIONS
IN URBAN AND PERI-URBAN AREAS (REGULATION OF WATER
RESOURCES, SURVEYS AND DESIGN AND LAND DRAINAGE,
FLUSHING SYSTEM AND MAINTENANCE)
Bv
S. SUBBA RAO
r
Prof. 6 Head of the Department of Sanitary Engineering,
All India Institute of Hygiene & Public Health, 110. Chittaranjan Avenue,
Ca1c ut ta
..e
1.
Introduction
It was Sir Roland Ross in 1899 who first enunciated a theory
that malaria could be controlled by control of mosquito population
through reduction of breeding places.
General William Crawford
Gorgas (1910) demonstrated the validity of this theory at the beginning
of the twentieth century when he achieved control of vellow fever in
Cuba through measures directed against the vector, Aedes.Aegvpti.
Gorgas also reduced the malaria rates in Havana through anopheline
control and subsequently gave a dramatic demonstration of the possi
bilities of this type of sanitation in connection with the construction
of Panama Canal.
As early as 1902 in Malaya a simple method of drainage
reduced the number of deaths in two small towns from 582 in 1901 to 144
in 1902; Sir Malcolm Watson (1910) proved the value of drainage and
site selection as two important approaches for prevention of malaria
in the same country.
I
..
Since the time of Ross's theory (1899) to the time of discovery
of DDT and its commercial availability in 1940's, the main attack on
malaria and other mosquito borne diseases was through adoption of
established Engineering methods of reducing mosquito populations, such
as regulation of water resources, source reduction by drainage, filling,
dyking, flushing etc. along with chemical control by the use of
larvicides.
But with the advent of DDT and other more powerful
insecticides, the emphasis altogether shifted from an environmental
approach to^ achemi ca 1 a pproach.
Both 'during the’ period ~f' “Mala ria
Corrtrol in 50' s and during the period of global malaria eradication in
sixties, extensive use of insecticides was made to break the chain of
transmission, and by 1965 this approach almost achieved malaria
eradication but thereafter deterioration set in.
There have been
alarming resurgences of malaria in some parts of the world since 1975
particularly in south Asia and India.
In 1975-76 one in everv one
hundred Indians was found to have malaria.
Causes for comeback of
malaria are many and complex.
But among them are, insecticide
resistance of mosquitoes, their capacity to modify their ecology and
biology when faced with adverse conditions, changes in the ecology
and environment of areas due to development schemes, resulting in
change of vector species etc. which have added a new dimension to the
problem of malaria and other mosquito borne diseases today.
Because
of these and other difficulties, it appears that a reappraisal of well
established permanent engineering methods such as regulation of water
resources, source reduction, naturalistic methods, flushing and
sluicing, land drainage, and ecological management etc., is urgently
required.
Since recurrence of malaria is more in the urban town and
peri-urban area than in rural a r ea s, these me t hod's are mor e appropriate
tOTlay—than—before-fo-r-the-xontrol^of mosquitoes in urban and peri
urban areas.
Chemical weapons may fail due to mosquito resistance and
drug resistance but Engineering methods if proper1 \\ designed .and
conducted and well maintained will ensure a constant degree of success.
Heiicfr-rt—is-thc -pur pose *b'f 'thi s“ pa per"t6"r e vl eb ‘ the 'Engin e'er ihg’met:
hods
method
available for mosquito control in urban and peri-urban areas, so that
2
I
more and more of these methods could be used to control mosquito
borne diseases, now and in future to compliment the recurrent measures.
Anti-malaria/mosquito engineering is a special technique based on
detailed knowledge of habits of mosquitoes, and it is one which all
development engineers, Sanitarians and those responsible for control
of vector borne diseases, including laymen should learn.
Successful
application of the techniques calls for a close collaboration between
P.H. doctors and Engineers.
Public cooperation is an undisputed
factor in proper implimentation of antimosquito works.
I
2.
Breeding places in Urban and Peri-urban areas
Water resources favourable for mosquito breeding may be natural
or man made.
Natural water resources in urban areas are (i) a river
or stream with sluggish or intermittent flow in the vicinity of the
town, (ii) natural lakes or ponds, (iii) low-lying areas flooded
during monsoon, (iv) marshy and swampy land in and around the town
due to ground water seepage.
Man made water collections are: (i) water
logging due to obstruction of runoff by railway or roadway embankment
with inadequate capacity in culverts, and other cross-drainage works,
(ii) borrow pits dug for construction of embankments for roads,
railway, canals and other construction works, (iii) ill maintained
swimming pools, (iv) overhead and underground storage tanks uncovered,
(v) abandoned brick fields and quarry pits, (vi) abandoned wells,
cisterns, cattle troughs and garden-pools, (vii) vent-pipes of septic
tanks and of pit-privies without mosquito nets, (viii) gulley pits of
underground storm-drainage silted, (ix) service privies and accompany
ing cess pools, (x) open surface sullage drains in medium and small
size towns with stagnant sullage and sewage, (xi) nikasi drains and
canals with sluggish flow of polluted water and with growth of algae
and water hyacinth, (xii) indiscriminate digging and dumping for
laying of water-mains, sewerage, underground cables, construction of
metro-system, creating many temporary or permanent water collections,
(xiii) insanitary cattle sheds inside the towns, (xiv) curing of concrete
floors holding water for 3 weeks (xv) small water collections in private
premises in discarded earthen pots, cigarette tins, flower vases,
overhead cisterns, roof-gutters etc.
Besides, in some periurban areas, storage reservoirs for
water supply and irrigation, canals, flood irrigation in the vicinity
of towns may also provide additional water resources for mosquito
breeding.
Uncontrolled sewage farming in the vicinity of some towns
provides breeding places for Culex mosquitoes.
Industries who throw
out waste waters indiscriminately create stagnant pools of clean and
polluted waters favouring mosquito breeding, both anopheline and
cu1icine.
In general the breeding places in urban areas are so numerous
that effective elimination of them will be an uphill task for the
It calls for a close coordination between
mosquito control squads.
3
the various agencies of Government and municipal administration
which are responsible for town development and
services.
Besides,
public awareness and cooperation is absolutely necessary for an
effective control programme.
3.
Survey and Mapping
A prerequisite to any mosquito control
programme is a malaria
or filaria survey to assess the intensity of disea
se, and to identify
the principal
.. 1 vector species and their breeding
places,
« -----------To help the
ma Jlanologists and entomologists in conducting these surveys and also
j these
for. carrying
.
out subsequent antimosquito measures,
measures, a map of the area
is absolutely essential,
The existing town map and the topographic
map of the area should be used as base maps on which additional data
can be plotted.
This makes possible maps of greater accuracy in
shorter time than these produced by sketch-mapping.
With the further
advantage that since many of the principal landmarks such
----- 1 as railroads,
highways, bridges, large buildings, low-lying areas, ponds, hills,
ranges, storage-reservoirs, screams and canals passing through or’near
the town are found on these maps with sufficient accuracy, additional
da ta regarding breeding places etc. may be added and oriented as
r equ ir ed .
If necessary the scale of existing map may be altered in
a drafting room to a scale more convenient for field use.
When suitable imaps and field equipment are not available,
Although lacking in accuracy, sketch
maps are adequate as preliminary maps and can be prepared with minimum
expenditure and time,
Later as information of greater accuracy becomes
necessary, more refined methods of mapping can beused, if needed.
sketch ma ps should be prepared,
. r
Although contouring is essential for drainage of marshy areas
and water-logged areas, contouring need not be undertaken in the
preparation of preliminary sketch map, which should be developed to
bring out the following pertinent basic data:
a) Main highways, rail-roads,
buildings, dwellings.
bridges, streams, canals, principal
b) All actual or potential mosquito breeding
areas.
These water
resources should be measured and delineated as accurately as possible
including ponds, cesspools, lakes, swamps, seepage areas,
wells,
canals, principal drainage channels and any other natural
or artificial
bodies of permanent or semi-permanent water which are actual o r
potential breeding areas lying within the flight range of the centres
of population.
c)
All potential drainage outlets should be accurately located
and indicated on the map to assist in planning progressive elimination
of water collecticns by drainage.
Such outlets include streams,
large canals, drainage channels,, creeks and the gulf or ocean.
4
d) At times it may not be feasible to locate every house in an
urban or peri-urban area on the map, although it is absolutely
essential to accurately define the boundaries of the areas to be
protected.
The equipment needed for making sketch map include a
plane-table with alidade, a compass, drawing paper (preferably square
paper) and a pencil.
Horizontal distances to the objects from the
point of reference can be measured by 'pacings1 for walkable distance
or by a milometer if an automotive vehicle is used for long distance
measurements.
A pace is defined as the distance from the heu. . i .'Ut
foot to the heel of other foot walking naturally. A stride is equal
to double the space.
For quick plotting of distances on the map, a
Pace scale chart can be prepared and used.
Long distant objects not
easily accessible for pacing could be located on map by the method
of intersections.
The sketch map should cover essential details.
Unwanted details will obscure the map.
The sketch should be accurate
and as complete in detail as time permits. A legend to the map should
be given.
If the town plan has already got contours, there is no need
to carry out a levelling survey in the whole area.
But levelling will
be required for antimosquito drainage schemes, for preparing accurate
longitudinal sections along the alignment of drainage channels to the
points of discharges.
The wellknown techniques of levelling should
be used by using dumpy or Wye levelling instruments, levelling staff,
chain and arrows etc.
The plotting scale for the sketch map should
be so chosen as to permit an optimum size of the map for ease of handl
ing in the field.
Generally a scale of 1 inch equal to 800 ft. or
I
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I
1 inch equal to 1600 feet should be satisfactory.
Besides location and delineation of public breeding places
during the survey and preparation of sketch map, in cities and
municipal towns it is also necessary to
L- make
--- a- house.to house survey
to locate cesspools, cisterns, empty containers , household septic
tanks etc. which are potential breeding places.
Once the
sketch map
map is
is ready with all existing and potential
Once
the sketch
breeding places identified and located, the next step would be to choose
suitable methods of elimination of breeding places or prevention of
breeding in those water collections.
This is the most vital step in
anti-mosquito operations.
Both the entomologists, malariologists and
the engineers who design and execute the anti-mosquito methods should
discuss and make judicious choice of methods for each situation.
The
/?
methods chosen are mainly guided by the type of mosquito species,
prevalence in the locality, their habitat and ecology, besides other
important factors such as cost, case of operation and maintenance
and the time involved.
A wrong choice may adversely affect the
situation leading to breeding of mosquitoes which was hitherto absent.
For example, in foothill areas most swamps are harmless,_but if drains
are dug
dug through
through ’Them~thesr^fte?
them these often “become dangerous breeding places
owing to aa particular
narticular species,
species, A.
M minimus, that breeds in drains.
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5
*
Digging of drains has been the cause of many outbreaks of malaria
in such regions.
On the other hand in plains, roost pools, swamps,
marshes as a rule are sources o f breeding and they should be drained
or filled. Another example of a species specific method is in the
ca se
of A.macula tus of Ma la ya.
Although river training eliminates other
species like A.minimus and A.fluviatilis which are breeders in running
water, this method will have no effect on
on A.maculatus
A.ma cula tus as it is a breeder
in faster-running streams,
The method of choice in this case is
subsoil drainage.
Cutting down of jungle and other vegetation is the
choice where the vector species in the area prefers to breed in dark
and shady areas.
But certain other species like A.maculatus and
A.minimus in Assam prefer breeding, in places exposed to sunlight.
Indiscriminate removal of jungle in the areas where such species
exist may have disastrous results.
In Assam where A.minimus is the
carrier species, growing of shade-giving trees over the streams,
drains, swamps, has been the adopted practice in certain tea estates
with positive results.
4.
Methods of Engineering Control
Several methods of Engineering Control of mosquitoes are
available.
They may be broadly classified as:
[
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
Drainage
Fillin8
.
~
Training and Channelisation
Flushing or sluicing
Dyking and dewatering
/
f
Pumping
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'lx
K
/
yj
\
>
z
Filling and deepening by mechanical mkarrT-’
jA
Clearing of vegetation, floating debris and aquatic
plant growth control
Water level management of storage reservoirs-*^^
Water level management in irrigation
Other naturalistic methods
Jungle clearing and shading.
f
/
Although all these methods are applicable in both urban and
rural mosquito control programmes,
programmes, some
some have
have aa wider
wider applicability in
urban than in rural.
I'
Methods like drainage, filling, channelisation,
flushing, pumping, clearing of marginal vegetationi are more widely
used in urban and peri-urban areas than water level management of
storage reservoirs and irrigation systems.
Some of naturalistic
methods are also useful in urban mosquito control.
Hence, further
detailed discussions are restricted to only those methods which are
more applicable to urban situations in addition to other special
measures required for urban mosquito/malaria control.
6
1
Drainage
4-1.1
Types.
Drainage is essentially a means of removing water in
order to prevent mosquito breeding.
Natural or man-made obstructions
to flow of rainwater causes water collections and creates conditions
favourable for mosquito propagation.
Natural barriers across rivers,
tortuosness, overgrowth of jungle, lack of adequate gradients in
streams, impervious subsoil causing marshes, ponds etc. are examples
of natural barriers.
Man made barriers are roads, railways, canal
embankments built without adequate waterways for cross country drainage,
drains, bunds for water supply and hydroelectric power, high sills of
culverts and bridges, excavation of borrow .pits,, brick fields, quarry
pits and a host of other man-made water containers as briefly mentioned
in an earlier paragraph,in urban areas.
Drainage to control mosquitoes differs from problems of storm
drainage. Object of the former is only to facilitate flow of water
under conditions which will prevent the breeding of mosquitoes
prevalent in the area.
If the drains carry water fast enough to
prevent breeding and will prevent the accumulation of water for more
than one week it is sufficient.
Storm drains on the other hand are
designed to carry the maximum expected floods in a day or a few hours.
Storm drains are larger, more expensive and do not cater for conditions
of dry weather flow which will cause breeding of mosquitoes. Another
type of drainage is in irrigation.
The objective of this drainage
is to intercept the excess water fed on to irrigated lands, carry it
off fast to drain the land quickly, and reuse it or discharge it to a
natural water course.
Here the design of drainage is mainly guided
by anticipated excess water flow over the land and high velocity
needed to drain the land so that crops are not affected adversely.
Drainage projects should be undertaken only after careful
survey and planning by Engineers and Sanitarians with the help of
malariologists. Drainage may be accomplished by the use of:
(1)
(2)
(3)
(4)
(5)
(6)
Surface drains or ditches
Subsurface or subsoil drains
Contour drains
Vertical drainage
Lido Drainage
Fascine subsoil drains.
The choice of any type depends on local factors such as
topography, contours (gradients), soil, climate and rainfall as well
as economic factors.
Surveys
4.1.2
Survey
s:
The first and foremost thing to be done in a drainage
project is to conduct a drainage survey.
Before undertaking a detailed
engineering survey a thorough reconnaissance of the area should be
made.
This is very important and should never be omitted as it enables
the designer to determine what kind of survey to be made, where it
7
should begin, and how it should be conducted,
During this preliminary
reconnoitory survey data should be collected on the following aspects:
|
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I
(i)
Location of breeding areas and their character.
(ii)
Sources of water, e.g. runoff from catchment, irrigation,
seepage, etc.
(iii)
Approximate population living within the mosquito flight
range.
(iv)
Type of soil and characteristics of trees and vegetation
on the proposed alignment of main drain and branch drains.
(v)
Whether or not a suitable outlet is available.
While
conducting the reconnaissance, the surveyor should contact
local residents who will be of much help in locating
drainage outlets and describing flow characteristics of
receiving streams i.e. HFL etc. so that he could judge
whether the outlet would be able to discharge into the
receiving stream without causing surcharge of outlet
channels.
All collections of water actually or potentially capable of
breeding mosquitoes should be accurately located on the map as already
described in a preceding paragraph, with their size delineated and
their position established with respect to habitation.
Sources of
water should be identified. Whether it is a runoff due to direct
precipitation or runoff from an adjacent area, or flow from an irrigated
land or seepage of water from ground water source should be carefully
investigated.
Estimation of flow from the first two sources are simple.
Wellknown rational methods may be used to estimate runoff from the
drainage area.
Similarly irrigation water carried through pipes and
channels may easily be estimated.
But it is more difficult to determine
the direction and quantity of ground water flow to be intercepted by
drainage to lower ground water table and to estimate seepage.
Seepage
outcrop is due to an inclined water bearing pervious stratum Ivihg
immediately above an impervious stratum.
Direction of flow can be
determined by digging test holes down to the water-table and conducting
a fluorescent dye test; the discharge can be measured by digging a
cross-ditch along the toe of the slope of hill, deep enough to inter
cept seepage outcrop and measure the flow.
In case of large swamps
and seepage areas, it is necessary to dig a series of Ees t *"Kd le s spread
over the whole area on a grid system, and to measure the distance to
the water table at different seasons; the layout of a surface or sub
soil drainage network should be determined.
Location of possible
outlets for low lying areas is important.
If drainage cannot be provided
by simple gravity drains, pumping has to be resorted to.
In most of
the coastal towns and even in some towns by the side of a river or
8
stream such a problem exists, the only alternative to gravity drainage
being to resort to pumping at least during the monsoon period. The
level in the flooded river may rise above the level of low lying areas
of the town requiring not only pumping of water from the city drainage
system, but also protection of town from flooding by raising of
embankment s. Borings along the proposed centre line of drains will be
required to indicate the proper slopes for side embankments, the
optimal type of lining of sides and bottom, and the level of the ground
water table, which in turn will determine the effect of drainage on
agriculture.
Once the preliminary survey is completed, a detailed engineer
ing survey should be undertaken and the system of drainage designed.
4.1.3
Design Criteria:
Drainage for mosquito control must be designed to carry water
with a velocity sufficient to prevent breeding of various local species.
A. maculatus can stand^higher velocities, while A.culicifacies is not
able to breed in channels with^clean margins in which the velocity of
flow is more thany^l. 5 feet/sec,jA minimum velocity of flow 2.0 feet
per sec., which is also the minimum self cleansing velocity for
suspended solids, is satisfactory from the point of view of mosquito
breeding.
If the drainage carries storm flows, then maximum velocity
at peak flow should not be high enough to scour the channel. The
drains are designed as open channel flow so that (i) the bottom is
low enough to drain the wet area, (ii) the capacity is sufficient to
carry the water brought into i£ (iii) the velocity of flow should be
within limits as discussed above, (iv) the sideslopes are such that
the banks will not slide or cave. The elevation of the drain bottom
is determined by ground surveys of the area to be drained, in relation
to the possible outlets.
The carrying capacity of a drain is based upon the maximum
runoff of the area and the rational method of estimation of runoff.
i
Q = CLA
is used for this purpose where
Q - Runoff in cubic feet of water per sec.
C = Runoff.coefficient value of C. ranges from 0.10 for flat
!,
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areas and highly pervious soils, to 0.40 for small agricultural
watersheds in roll ing terrain, to 0.95 for city pavements
and roofs.
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N’ i
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Rainfall intensity, in inches per hour.
A = Watershed area,
(Note:
in acres.
that it”j1it” should be determined by study of previous data on
intensity and duration of rainfall in the area, and by drawing the
intensity-duration curves and choosing a storm frequency of twice a
!I"'
V '•
9
year to once in two years depending on the importance of the area
flooded.
Commercial areas should be subjected to less flooding
than dwelling areas.)
The channel capacity is given by basic Chezy’s formula.
Q =A.V.
Q = Discharge to be carried, in cubic fe.et per sec.
A = Cross-sectional area of channel,- in square feet,
V = Velocity of flow in feet per sec. = C Vrs
(Note that velocity of flow depends on the hydraulic radius 's', the
surface slope or fall per foot, and ’C' a Coefficient,
'C' can be
worked out from Rutter's or Manning’s formula,
The gradient to be
chosen is guided by the natural slope of the land.
The desirable
minimum grade of a drain varies with many hydraulic factors, most
important being the volume of flow and hydraulic radius.)
4.1.4
Surface Drains:
Open or covered surface drains are extensively used both for
storm and antimosquito drainage.
4.1.4. 1
Earthen drains
For antilarval efficiency open earthen drains (Kutcha drains)
should be narrow and deep (l'-2' width is sufficient in most cases)
The gradients suitable for small earth
and not broad and shallow.
Gradient suitable for large earthen
drains are 1 -in 50 to 1 in 200.
drains is 1 in 200 to 1 in 1000. Width of drain is bottom width or
width of invert.
Side slope of earthen drains should be steep enough
to stand by its own angle of repose i.e. 1 to 1 or 1-1/2 to 1 for loamy
soils, stiff clay 1/2 : 1, and sandy soils 4 to 1.
Turfing is necessary
7 on earthen slopes to prevent scour.
The spoil should be thrown at
least 31 away from edge of the drain and should^not. obstruct natural
drainage; it should preferably be used for filling, or may Ve-spread
and gently sloped.
If stacked as soil banks, passages should be left
through which surface water can flow into the drain.
Scupper drains
are put in wherever there is a cross drainage to be made. At the
junction of scupper drain with main drain, stone pitching and training
on the sidewalls should be done to prevent scour.
Joining of two
drains should never be at right angles as erosion and sand shoals
will result.
They should join at an acute angle.
The nose of the
junction should be protected by pitching of stones or concrete.
Eddy
fo'rraaTion Ts to be prevented where pipe ^drains join an open drain.
The outlet should conform to the side slope of an open drain.
Wherever there is a change from a steeper gradient to flatter one,
10
silt will be deposited in concrete channels.
Sand traps are to be
provided by making an excavation (10-15' in length) deeper by about
one foot than the rest of the length of the drain, When the ground
falls steeply, it may be necessary to reduce the gradient of the
drain to prevent erosion.
This is accomplished by a series of drop
walls. Aprons are required to prevent erosion below dropwalls.
Cattle crossings should be provided in all earthen drains.
Lining of Earth draii:
1/
4.1.4.2,
r
Lining of drains is a useful measure to prevent the erosion
and scouring frequently seen in earthen drains. A lined drain may
require only half the cross section of an unlined drain with
irregularity of cross section, and will save a great deal of mainte
nance, such as repeated regrading, cleaning and even oiling. Several
types of ditch lining are in common use and the choice will depend
on local conditions.
The term invert is used to describe a section
of durable ditch lining which covers the bottom and part of each
side.
Inverts may be cast' in the drain itself.
Precast inverts made
of vitrified clay tiles, cement and concrete are more commonly used
for quick lining.
Brick or stone pitching with cement mortar jointing
and pointing are also used. Wood is rarely used.
Precast concrete
inverts are becoming more and more popular.
I
4.1.4.3
Lined ditches are more durable, more easily cleaned, less
in netu of inspection, less likely to breed mosquitoes than unlined
drains.
In urban areas unlined drains are not recommended. Only lined
drains with brick or stone masonry side walls and concrete invert are
suitable.
As a rule the lining should be 'U' shaped with sloping
sides.
Sometimes it is necessary to extend the lining only a few
inches above the nomal water line.
It is usual to provide sloping
sides
and
sometimes
in bottoms of the lined ditches
seepholes in the
\ *
When
ground
water level is high, the dry
for entry of seepage water.
v joints of precast inverts allow seepage to enter the drain. The
bottom lined drains should have in the bottom a central narrow channel
as a subdi^tch or cunette to take the dry weather flow.
Best suited
shapes for surface drains are rectangle, trapizoidal, semicircular,
semi-peg top and ovoid.
For inverts, semi-circles of 3 to 18
diameter are commonly used; 'V' shape is unsuitable as it leads to
clogging and presents difficulty in effective cleaning.
Digging and
construction of a drain should start from the lower end of drainage
But in cleaning an old drain
as it can function from that instant.
the work should start from the upper end.
4.1.4.4
Digging of drains
In a large drainage project manual digging may be replaced
by machine digging for economy and speed of work. Many types of
trench excavators, such as dragline and chain excavators, can be used.
11
4.1.4.5
Blasting
Blasting of open earthen drain in wet or marshy ground and
through heavily wooden swamps is the least expensive method of
excavation.
To the mosquito-control engineer the blasting method
is particularly valuable, as it is the quickest known means of
constructing open earthen drains for drainage of marshy land and good
progress can be achieved. A crew of 6-8 men skilled in blasting can
ditch about half-a-mile a day.
Nevertheless it is a specialised job
and calls for an experienced blaster to supervise operations.
Blasting
is not advocated in the habited areas.
4.1.5
Surface drainage in Urban areas
In many medium sized and small towns, surface drains are the
only drains provided for drainage of storm runoff.
The drains are
generally lined, but kutcha drains are also constructed in many parts
of the town due to paucity of funds.
These drains get filled up with
silt, clay, waste construction materials, refuse etc. and gradually
fail to carry the flow and forms pools of stagnant polluted water,
.which are ideal for mosquito breeding particularly of Culex.
The
drains are neither cleaned of clogging debris nor maintained in good
repair by the municipal authorities for want of funds.
The outfall
nallah is generally a nikasi drain, silted and overgrown with weeds
and vegetation, and leading to stagnant cess pools.
L
For prevention or reduction of mosquito breeding in these
drains it is necessary to clear them completely, and repair and
reset them to proper grade and alignment providing a cunnete for dry
weather flow.
Cess pools should be drained, and a proper outfall
drain made with a well-designed and constructed discharge outlet into
the receiving stream.
In addition, broken culverts need to be re
constructed.
"
4.1.5.1
Contour drains on hill slopes are useful in dealing with
seepage water but it is necessary to treat them systematically with
larvicides.
4.1.6
Sub-Soil drains
Sub-soil drainage in mosquito control projects is adopted for
the following situations;
(a)
As an alternative to surface drainage in flat lands,
in order to lower the ground-water table so that surface
pools are more readily absorbed into the ground.
(b)
To intercept seepage outcrops, and drain marsh lands
and swamps.
(c)
To deal with hill streams in ravines.
(d)
In agriculture to save land which otherwise would have
been occupied by open drains.
12
I
Four types of subsoil drainage layouts are commonly used (see Fig. 1).
(i)
Random system: Used for draining low narrow depressions
The lines of pipe follow the lowest portions of depression.
(ii)
Grid-Iron system: Economical for flat lands of uniform
slope. It has a mainline running along the edge of a
field with a system of long parallel laterals entering
at an angle of 45:. Sometimes it includes a sub-main
channel.
(iii)
Herringbone system: The main is laid in the lowest part.
Laterals enter the main at an angle of 45°, offset.
(iv)
Intercepting system: This is used to intercept and remove
hillside seepage before it can move out upon flat or
depressed land below.
r
FIGURE
I
A.
|. TYPES of subsoil, drainage >
YT
B.
^-HERRINGBONE PATTERN, B-GR1D IRON SYSTEM,
C' INTERCEPTING SYSTEM for NARROW RAVINE,
n- INTERCEPTING system for wide ravine.
’
.1
\\
. 11
/
. Il/
w
-------CL
1
— b
-—CL
b
b--
—c
I ]
3
-- d
c.
CL; iN’reRCEPTlNS PIPE ONE,.
b. collecting pt’fFE,
INTERMEDIATE
C . MAIN
PIPE, dL
pipe.
13
Just as in surface drainage schemes, preliminary studies should
be made to ascertain characteristics of soil, level of water table and
sub-surface configurations in order to work out proper design of the
subsoil drainage system.
In dealing with the problem of drainage of
a seepage or swampy area in a ravine, it is first necessary to clear
vegetation and dig contour drains from the lower end of the valley
before laying sub-soil drainage.
This will open up swamp spots,
making breeding places clear.
Further it will also remove the surplus
water and therefore make working within the marshy or swampy area
easier and aid in the task of laying subsoil drainage,
In fact Hunter
by his experience in subsoil drainage at Singapore suggests that first
the ravine be provided with open drainage and oiling for some months
before the subsoil drainage is installed.
i
u
T >--
The depth, gradient and spacing of latera 1 and main drains
depends on soil permeability, water table level and the natural
slo pe.
In any case pipes should not be laid at depths shallower
than 4 feet or they may be damaged or choked by entry of plant and
tree roots.
To lower the subsoil water a gradient of at least 1 in
400 is usually required.
In sandy soil a gradient as steep as 1 in
100 for 4" pipe and proportionately less for larger pipes is required.
To intercept seepage a gradient of 1 in 200 is recommended and sub
soil gradients steeper than 1 in 30 are not recommended.
Similarly,
the length of drains should not be excessive.
The smaller the size
the greater the friction loss.
For example, a 4” pipe laid on a
grade of 1 in 1500 should not be longer than 1500' whereas a 12"
pipe laid on the same grade or even flatter could extend to a length
of 5000 ft.
Similarly, spacing of lateral drains depends on soil
composition.
Drains should be kept closer in clay than in sand or
gravel.
In a mixture of clay and fine sand with water table less
than 5' the depth should be 6 feet below the surface and spacing
should be 7' apart,
In sandy soil with water table any distance
below the surface, the depth of drain may be 4-5 feet and spacing
100-200 feet apart.
Subsoil drainage should discharge freely into streams or
di tches.
The outlet of a subsoil drain should be carefully constructed
that its outfall is free and does not create a mosquito breeding
nuisance.
On the -other hand, Dr. J.W. Scharff who had a wide experience
in antimalarial drainage suggested that the outlet need not necessarily
be a free discharge all the time, as it will frequently result in
having the pipeline laid at shallow depth; as a rule outlets should
discharge with the lowest practical outfalls even if this means
outlets are occasionally flooded.Drains are made of burnt clay,
vitrified clay or concrete pipes of short lengths ranging in diameter
4" to 12".
Trenches are excavated from the down stream end, levelled
Th e
and pipes are laid loose jointed without any jointing material,
top semicircle on each joint is covered with palm leaves, rubber
strips or kneaded clay to prevent water entering from top portion and
the backfilling is done carefully and tamped.
The topsoil should be
replaced so that grass may take root over the pit.
In loose soil,
14
The pipes should
backfilling should proceed immediately after laying,
have a capacity to carry 4-5 times dry weather flow, As a thumb rule
they may be designed to remove 1/4" to 1/2" of water.in 24 hours.
No
trees should be left within a distance of 40 feet of subsoil drainage
lest their roots enter and block the pipes. Wells should be provided
at suitable places to serve the threefold purpose of silt chambers,
inspection wells and cleaning points.
The minimum width of these
wells should be 24" for ease of cleaning.
Several expedients can be used in subsoil drainage.
They
are (i) clay or concrete pipes filled with kneaded clay with covering
over top and side of joints, (ii) Pipes covered with stones or gravel
for extra permeability, (iii) Hard wood or hollow bamboo in place of
clay pipes.
No rain water or household sullage water should enter
subsoil drainage. Where such a situation exists, a superimposed
concrete channel for carrying sullage or rain water should be provided.
4. 1.7
Fascine drains
These are a form of subsoil drains more adopted to rural
conditions.
Bundles of sticks 2" - 4" in diameter tied in bundles
of 1’-4' diameter and 6-15’long are laid in excavated trenches with
their buttends facing upstream.
They may be supported every 4’ on
cross pieces of wood placed over short stakes and covered with earth.
The low water which is favourable for mosquito breeding particularly
anopheline will be taken underground, and the absence of light together
with mechanical Construction and pollution if any will inhibit breeding.
i
Subsoil drainage has been most effective in dealing with
hill streams, seepages and swamps.
But the cost is prohibitive. In
case of plantations, the disadvantage is the removal of all trees in
the vicinity of drainage to prevent choking with roots thus resulting
This together with heavy cost of maintenance
in wastage of land.
resulted in the owners of many estates in Malaya abandoning subsoil
drainage and reverting to open drains and oiling.
4. 1.8
I
Vertical drains
When water is held on the surface by an impervious stratum
which is overlying a pervious stratum like hard pan underlaid by sand,
it may be more economical and effective to adopt a vertical rather
than horizontal drainage.
In vertical drainage a hole is bored through
the impervious layer into the pervious layer so that water will drain
into the pervious layer and be carried through it.
It may or may not be
necessary to line the vertical drain to prevent erosion.
Screened
drainheads are necessary to prevent entry of coarse material and
debris. A situation where vertical drainage is feasible is a clayey
top layer overlying a limestone stratum.
Boring holes through the
impervious layer may be done by hand-boring tools and machines or by
dynamite.
Gorman used dynamiting to drain a pond of 1800 x 50
vertically.
The pond was in the centre of a city but its bed was
several feet below the invert of the city sewer, and horizontal
!
15
drainage in this case was difficult and costly,
Stromquist drained
a pond of 40 acres using a 7 ft. square shaft sunk to 40 feet lined
with 2x6 inch timber double braced at intervals of 3’ and with
2 x 12” sheathing.
This type of drainage is useful if the geological
formation is favourable, and it could be used for small collections
of water.
Collections in towns and cities caused by leaky public
water taps, pot-holes and road ruts in clayey soil which are a
considerable source of mosquito breeding should be removed by short
vertical drains or absorption wel Is filled with porous material.
Before adopting this method of drainage, however, the possibility of
ground water pollution should be critically evaluated.
4.1.9
Lido drains
Where conventional drainage cannot be provided on account of
lack of funds, the method of Lidoing can be adopted in areas where
rainfall is moderate and not high.
It consists of excluding storm
runoff over the area to be drained by cheap bunding and dressing the
area so that all rain water will flow into a single depression which
is sized to required capacity. All other pits in the area are filled.
Thus area available for mosquito breeding is minimised and larviciding
becomes easier and economical.
The method can be applied to a series
of burrow pits along the embankments of railways, roadways or canals,
provided ground slopes are favourable. A chain of burrow pits could
be interconnected to drain to the lowest pit which could be sized
to collect all water drained from above; larviciding will then be
cheaper and economical.
But this is no substitute for excavating
burrow pits in such a way that water does not collect and fill up
the pits.
5.
Filling
Filling to eliminate breeding areas can be adopted in a number
of situations.
Many of the land reclamation schemes in coastal areas
have been the result of diverting the flood water bearing 16-25% of
suspended silt on to low lying marshy lands, but it requires long
range planning and continued mosquito control operations in the filled
area till the level is raised and the silt laden liquid dries up to
form dry land.
Further treatment of shrinkage cracks developing in
the reclaimed land will be necessary to eliminate breeding of mosquitoes.
Old quarries and brick pits can be silted up very cheaply by
diversion of small streams,
A marsh land in Assam was converted into
sandy flat by diverting a silt bearing stream.
Pools and shallows in
stream beds can be filled up naturally by constructing groins.
Filling tree holes with earth, sand, gravel asphalt or cement
prevents breeding in these small collections,
Asphalt is probably
the best for this.
16
/
Rock pools can be filled by cement to eliminate breeding.
Moats in and around towns, small ponds and other low lying land which
cannot be drained can be filled by city solid wastes through controlled
tipping, taking care to see that all empty containers are crushed
before filling or burial.
This will result in reclaiming water-logged
and waste land areas, and permit establishment of parks and playgrounds
and even buildings after several years.
Materials used for filling
should be relatively porous, if possible, because if water retaining
'erial like clay is used then any slight surface depression may
hold back water long enough to breed mosquitoes.
Brick pits are
filled with earth.
No brick factory or stone quarry should be allowed
within a distance of a mile from habitation.
Burrow pits in and around the Itown should all be filled
up.
Burrow pits excavated for canal embankment can be filled by cutting
earth from a field just above the dug area , lowering the level of the
field thus not only eliminating the burrow
pits but also increasing
land under irrigation.
In all cases o f filling it is important to level the surface
so that no rain pools will form.
Inert materials like waste building
ma teriaIs, solid industrial wastes, <cinder and ash, saw dust etc. are
more suited for simple filling and consolidation
--------- 1 than organic refuse
Which requires sanitary land filling operation
and control.
control. A special
operation and
method of reclaiming swamps is by hydraulic fill, high silt laden
liquid being obtained by dredging operations in estuarine rivers
subject to heavy silting.
6.
Stream Training and Channelization
The |purpose of stream training is to induce the fastest
possible flow in
1- the stream or river concerned.
This measure could
be adopted in relatively small streams which have a sluggish and
intermittent flow and irregular cross section.
F*
River training
consists of increasing embankment slopes to reduce‘ area on side
flanks exposed for water collections between HFL and LWL,
, improving
longitudinal1 grade by removing such impediments as fish traps,
boulders and brush from the water course,
rebuilding cattle crossings,
straightening streams and reshaping banks, besides dredging a shallow
channel down the centre of the river bed.
This will either cause
complete drying up of many kilometers of sluggish
or stagnant pools
or restrict the water to a narrow central channel which could be
effectively larvicided.
7.
Flu sh i ii
For effective flushing a O
uii1Ciently large
sufficiently
large volume
volume of
of water
should be discharged suddenly at a minimum
once aa week,
week, or
or more
---- of once
often, with the object of causing a wave to pass down the channel or
stream,
This wave as it flows onward causes the stranding of mosquito
larvae, pupae and eggs.
Its effectiveness depends on a number of
things: turbulence, splashing, stranding, the stirring up of silt,
17
and the erosion of margins which is unfavourable for establishment
of vegetation, algae etc.
That serve as food <or shelter to larvae.
Many devices have been used including simple hand
-J operated gates in
dams, Jiggers used in Malaya, and cairefully
"
designed automatic
symptoms, the latter appearing to offer one of the best types of wa ter
contro1.
Automatic Syphons
Devilliers, Macdonald, Williamson and Schraff, Worth and
* - -------;
have originated and adopted syphons for sluicing in
mosquito control.
The designs of Macdonald, Legwen-Howard, and
Subramanyan-Worth are shown in Fig. 2.
They are basically similar in
principle but differ in details.
PIPE
C.ASS
y I,s
£
co
H
II
II
If
I'
COVER
------ WE!R
*—CAS2E
TOU^H
II
"y-l— e,AS£
SEarfo^.
MACDONALD
SIPHON.
V
‘J
V
A
C/?OWA/—
-"THROAT
SEALING
V
-GFtesT
VPPRR LIMB — —
SECT/O.^
F UNHEL
C S UBRA PA A/ YA N <
L tp
R
'Lowe* limb.
If
^-PR/MWS VsfJT
-AA-^eaeing bAS/N
/)
LEG WEN HOWARD 5/PHON .
Dam
~
GO GALLONS
——--------- ---
x
----
-----------x/LM<?y
.. ------ ./ SIPHON.
f
r-y /a PPCJ
t
( f
£D/A
FT (H
/
— J:___
rn-*
Fow//
e>trpam
PROTPCT/ON
7/ z
r» ."j-1 rn
Qarrbl.
----- ~ p Tuse (
SIPHON.
s-w.P/Pf
18
The principle is to impound water by a low dam across the
stream or river during the mosquito breeding season. When the impounded
water reaches a predetermined level, the syphon discharges it rapidly
as a flood wave that flushes a certain length down stream. The syphon
discharge stops when the water level falls to a predetermined level.
In Sri Lanka over thirty syphon dams were constructed during 1939-40
in rivers at widths ranging from 10' to 150' to control A.culicifacies.
On experimental syphons Worth and Subramanyan determined the area of
syphon required for different widths and slopes of stream in order
to obtain an effective flushing length of approximately 5000’ below
the dam with a syphonic head ranging from 25 inches to 40 inches
(as presented in the following table).
Area of syphon opening required in square feet for
river flushing
Slo pe
of
stream
30
60
80
100
150
1 in 50
1.41
2.82
3. 76
4.70
7.05
1 in 100
2.01
4.02
5.36
6.67
10.05
1 in 200
2.82
. 5.64
7. 52
9.43
14.14
1 in 400
3.99
7.98
10.64
13.33
20.00
1 in 600
4.89
9.78
13.04
16. 33
24.50
1 in 800
5.64
11.28
15.04
18.88
28. 32
1 in 1000
6.33
12.66
16.88
21.08
3.62
Width of stream in feet
1
f
[
Source: Worth, H.N. and Subramanyan, K., Jr. of Mai. Inst, of India
3,1, June, 1940
Syphons may be precast or cast in-itu. A battery of syphons required
for large rivers, They also can be installed on existing spillways
of dams, Syphons must be designed to discharge sufficiently fast to
give more than the velocity required to control the local mosquito
species, This involves hydraulic consideration of head, width, slope,
and roughness of stream, The length flushed depends on rate of
di scha rge, the quantity of water stored above the syphon dam, and
width and slope of stream, It also depends on inflow of stream at the
moment. With dams 2-2 1/2’ high length flushed is about 1500’.
f
19
With dams 4-4 1/2' high length flushed is
0.75 to 1 mile and the
flush is stronger.
Higher dams than these
may cause submergence of
adjacent lands, and perhaps may take more than
a week to fill.
Syphons dams can be built in the neighbourhood of
towns and villages,
Concrete is the most suited material of cconstruction for syphons.
But simpler devices can also be used like
the barrel syphon shown
in Fig. 2, for small streams and drains 6’
to 20’ wide.
In hilly country the syphon dam should be made strong enough
A t very low flows, the syphons will not work
h.v :.pite. At
within a period of a week.
For such situations s sluice should be
provided which could be manually operated
to flush once a week.
tn
’ * * ‘ ’
Jigger is another type of automatic
flushing device designed
and used in Malaya by Professor Williamson,
It consists of wooden
buckets placed into aa low
low dam
dam across the stream,
The flow in the
stream fills the
t’
buckets and tips and discharge into downstream. A
counter-weight lever brings it back into
an upright position for
filling and emptying again,
Rubber packing s between the bucket and
dam face are provided to prevent leakage
between the bucket and the
dam.
8.
I
Other measures in Urban mosquito control
8. 1
Besides construction of new drainage for effect!
of water collections, existing drainage systems require ve prevention
proper modification, renovation, cleaning so
water or waste water is
so that
that water
a Lwa vs
kept flowing with a minimum velocity
of 2'
locity of
2 ' per sec to minimise mo sq u i to
breeding.
All appurtenences on <existing sewerage systems should
be kept
in good working condition and in good repair.Gully pits are a
po t ent ia 1
source off breeding.
They should be regularly cleaned of silt after
every shower to jprevent
----------- water stagnation in them.
Similarly all
auxiliaries of water distribution
------------ systems should be kept free of
1 ea ka ge .
Open storm drainage systems in country towns should be kept
10cu,ldit-i°n a"d regularly cleaned and oiled.
To ensure adequate
veUcity of flow during dry weather, sections should be checked and
remodelled with a semi-circular Cunnete for the inver^for this
purpose.
Covering of all surface drains i_s_pre f erred J Septic tank
effluents should not 'be~a1lowed into thiss system,
system.
Eich septic tank
should have its own subsurface disposal trench
trench or
or soak pit.
8.4
All overhead and underground water storage tanks should be
covered, and the ventillators should be checked for mosquito proof
nets.
Similarly all vent pipes provided in septic tanks and in
on-site disposal latrines should be covered by mosquito proof netting.
20 8.5
Service latrines should be replaced by uon-service type
la trines.
8.6
Open drainage nallahs should be lined and channellised to
ensure adequate velocity of flow throughout the season and cleared
of marginal vegetation, floating debris, aquatic plants like water
-hyacinth, weeds, algae, and pistia which provide shade or abode for
eggs, larvae and pupae. Installing flushing devices as discussed
earlier may also be looked into.
8.7
All lowlying lands and marshy lands, abandoned wells and ponds
should be either drained or filled as discussed in earlier paragraphs.
8.8
Swimming pools should be kept in a clean and unpolluted
conditini
Top feeding minnows like Gambusia may be introduced in
wells, ornamental tanks, water tanks for gardening, and other permanent pools.
But they should be periodically checked for predators
that may devour them.
8.9
Throwing of rubbish, garbage, discarded construction materials,
cut branches of plants and trees etc. indiscriminately into city
drainage systems is one of the major causes of water stagnation. This
requires vigilance on the part of the civic authorities, and also an
efficient solidwaste management system. Education of the town people
and their cooperation is essential for successful preventive health measure
8.10
Cattle sheds (khattals) inside the cities and towns are a
source of mosquito and fly breeding. Civil authorities should
strictly enforce laws to remove all these to outside the city limits.
8.11
Private premises should be inspected by mosquito control
personnel at least weekly to identify and remove the small water
collections described earlier.
8. 12
Concrete floors in construction work may be cured by flushing
once each week.
8.13
Health education of the public through mass media regularly
will help to obtain the people’s cooperation.
8.14
Developmental authorities for roads, railways and urban transit
systems should consult civic authorities before laying of new roadways,
railways or upgrading of existing roadway or railway embankments, in
order to avoid interference with the natural drainage system of the
town and to cooperate in making appropriate drainage plans and designs.
9.
Maintenance
9.1
Efficient maintenance of all anti-mosquito engineering works
is the keynote to the success of mosquito control by permanent engineer
ing methods.
Important maintenance aspects have already been discussed
under different methods of control.
In large cities and towns there
is justification to have a separate department for maintenance of
21
of drainage and other antimosquito works.
The department should be
headed by a P.H. Engineer trained in mosquito control works.
Oth<=»r
works.
technical and field staff of the department should receive inserv- -e
receive inservi
training in mosquito control measures.
Drainage is
the main problem
is the
of cities and towns.
Regular cleaning of drains and
their upkeep
forms the major part of the work of these trained men.
Besides
maintenance of channels, important functions are the grading and
sloping of embankments, and clearing of marginal vegetation
algae
and water-hyacinth.
Periodic inspection of houses to check water
collections, vigilance to preventcreation of dumps obstructing
drainage, and control of digging that might create pods, form
a pe r t
of the work of this department.
Periodic checking of public taps and
standpipes, and their waste water disposal drains or soak-pits, and
examination of ponds and swimming pools is essential co preven t
creation of conditions favourable to breeding of mosquitoes.
Inter
disciplinary co-ordination between the Departments of ?.H.
Road s
and Railways, and Building and Irrigation is essential f
proper
maintenance of canals, roads, bridges and culverts, river and
stream regimes, antimosquito drainage, storm drainage, tica1 gates,
flood control embankments, sluice gates, and automatic syphons etc.,
so that flooding and/or stagnant pools are not created and zosquire
control measures are effective.
10.
Summary and Conclusion
10.1
Most of the breeding places in urban and periurban areas
are man-made and can be effectively eliminated by acozzing suitable
engineering methods.
10.2
Several methods of engineering control of moscuitoes are
available, and choice of method for a particular situation should b e
carefully made by joint consultations between P.H. Engineers and
malariolegists.
Suitability of methods is guided by the breeding
habits of the local vectors and their ecology.
10.3
Different types of drainage for mosquito control mav be
employed, viz. surface, subsoil, vertical, contour, Fasine. Lido,
Each of these methods have specific indications in urban zoscuito
con tro1 pro grammes.
10.4
Filling of all types of depressions ha s a special significance
in urban mosquito control.
10. 5
Training and channelization of small streams near towns is
nec es sary if they are sluggish and have an intermittent f lo - .
10.6
Sluicing and flushing of streams and channels co destroy
mosquito larvae and pupae can be adopted for small and —edium size
s trearns.
Automatic syphons are best suited for this purpo se.
22
10.7
r'
Clearing of vegetation, iremoval of cattlc/sheds, removal of
solid wastes,> use of larvivorous fish in
--- -.i ornamental ponds and fountains,
covering of all vent pipes with mosquito gauzes, periodic inspection
of private premises for removal of small water'water
containers, are
some of the special measures necessary for effective
mosquito control
in urban a rea s.
10.8
All categories of Engineeries, P.H.
doctors and Sanitarians
involved in mosquito control work should be
adequately trained in
engineering nrpects of mosquito control operations.
academic
as well as {practical training ahould be organised at Both
several |
teaching
institutions in collaboration
i with national institutes for malaria/
filaria control.
In conclusion, it may be said that with the resurgence of
malaria and its ]particular problems of vector resistance to insecticides
and parasite resistance' to drugs, and in order to control filariasis
engineering Tl
methods of imosquito control are becoming increasingly
important,
These methods are sometimes expensive and may not always
be feasible. Tbey also require specially trained Engineers and
Sanitarians. But to the extend funds
permit, there is a strong case
to revive these methods as supplements
to the chemical and biological
warfare against mosqu i toes.
Bib 1 io gra phy
1.
Boyd, M.F.. Malariology - A Comprehensive
survey of all aspects
of this group of diseases from a global standpoint, Vol.
2,
Pub. W.B. Saunders Co. bond., 1949.
2.
Russell, P.F. et al: Practical Malariology.
Pub. Oxford University Press. 1963.
1
2nd Edition,
3.
Manual of Hygiene for the Armed Forces. 1953. by Director General
of Armed Forces Medical Services, Govt, of India.
4.
B.N. Ghosh, A treatise on Hygiene and Public Health,
4th Edn.
l*ub. Scientific Publishing Co. , Calcutta, 1965.’
5.
Logan, John A.: The Sardinian Project Baltimore.
Press. 1958.
Johns Hopkins
6.
Worth, H.N., Subramanyan, K. , Antilarvae flushing of Rivers and
streams in Ceylon - Jr. of Malaria. Instt. of India, 3,1,
June 1940, Page 81-92.
7.
Macdonald, G.: The design of flushing syphon for control of
anopheline breeding. Jr. of Malaria Instt. of India,
2,1, p . 63-69 .
!
I
)
HEALTH ASPECTS OF WATER RESOURCES PROJECTS
V.P. SHARMA
MALARIA RESEARCH CENTRE
22-SHAM NATH MARG
DELHI-110 054
titled "water associated vector borne
Prepared by combining working papers
Indo-USSR
diseases in water resource development projects presented to the the vector
travelling workshop,1987 and ’’Impact of sectoral policies on PEEM meeting
borne disease situation in India" presented for the 9th
Geneva, 1989.
DIS
3'^
LIBRARY
(
03°|35_
L
AND
DOCUMENTATION
V.
UNIT
j
P
h
1. INTRODUCTION
1.1
Vector borne diseases :
In India the main mosquito borne diseases
are Malaria, Filaria, Japanese encephalitis and Dengue. India is endemic
for malaria except areas above 1500 m mean sea level and some coastal
areas. In pre-control era - 1948, an estimated 75 million cases and 0.8
million deaths used to occur annually due to malaria alone in India,
As a
result of The National Malaria Control Programme (NMCP) launched in 1953
and later converted to National Malaria Eradication Programme(NMEP) in 1958
the malaria incidence was brought down to about 0.1 million by 1965. This
was followed by malaria resurgence and the cases gradually increased to 6.4
million in 1976. Implementation of the modified plan of operation (MPO)
since 1977 resulted in the decline of malaria cases to about
22 million.
During 1988 NMEP reported 1.6 million cases of malaria, of
of which P.
falciparum
constituted 0.5 million (35/0. There are nine vectors of
malaria in the country, Anopheles stephensi is the vector of urban malaria
which breeds in wells. overhead tanks, cisterns and rain water puddles
etc. Almost all urban malaria in India is transmitted by A. stephensi.
Anopheles culici facies
facies is the vector of rural malaria and peri-urban
malaria.
Tt is found in most parts of the country and has been
incriminated from a large number of a reas.
The vector prefers to breed on
ground and there is a sudden spurt in its populations with the onset of
rains, It also breeds in a variety of other habitats such as wells, ponds,
rice fields, irrigation channels. seepage water and marshy areas etc.
Other vectors are of local importance such as A. b
I alabacens i s (di rus), A.
phi lippinensi s (ni vipes), A. minimus, A. f luviTFi l~JT7r A.varuna, A.annularis
and A. suncJTTcus.
India is endemic for filaria and about 360 million people are exposed
to the
risk of its transmission.
There are 18 million microfilaria
carriers in the country and 8 million people with disease manifestation.
Wuchereria bancrofti transmitted by Culex quinquefasciatus
is
'
i s the main
vector followed by a small focus of Drugia malayi transmitted by Mansonia
annuli fera,
The later infection is fast disappearing and getting replaced
by W. bancrofti
-•«. The problem of filariasis is not fully delimited. Culex
quinquelasci atus breeds profuselyI in
polluted
r
waters,
and constitutes
the
IhjIT ol mosquito populations responsible for high nuisance both ini rural
and urban areas.
Japanese encephalitis (JE) transmitted by Culex vishnui group of
mosquitoes occurs in sporadic form. JE epidemics were
first reported from
u/ere
4 districts of West bengal in July 1973.
Thereafter
1hereafter JE epidemics are
reported every year from West Bengal, Bihar, Uttar Pradesh, Maharashtra,
Andhra Pradesh and Tamil Nadu. There is high morbidity
morbidi ty and mortality
associated with JE epidemics. The seasonal occurrence of JE coincides with
spurf in Culex tritaeniorhynchus populations.
The vector mainly breeds in
rice fields, but also breeds in drains, ditches and fish ponds. .The
epidemics occur in rural populations that live in huts close to paddy
fields and rear pigs.
Dengue is transmitted by Aedes aegypti which is a container breeder,
It breeds profusely in urban areas in overhead tanks, cisterns, water
stored in a variety of containers, desert coolers etc. Periodical dengue
fever epidemics have been encountered in urban areas in the country.
2
1
1.2 Irrigation
:
India’s irrigation
potential before launching of
the 5 year plans was 22.6 m ha. During the successive five year plans there
was spectacular increase in irrigation in the country (see table 1). At the
end of 6th plan (1980-85) 75 m ha would be under irrigation and the growth
rate during
the
first 25 years was 1 m ha per year.
During the
subsequent years this growth rate has been stepped upto 2 m ha per year.
The number of projects initiated (including spill over from the previous
years) at the beginning of the 5th (1974), 6th (1980) and 7th (1985) plans
were 75 major 155 medium, 176 major 447 medium, 240 major and 540 medium
respectively.
Seven hundred dams have been constructed and storage
capacity is being increased from 160 thousand million cubic meters (mcm) to
234 thousand mcm (anonymous 1984).
TABLE 1 : CUMULATIVE POTENTIAL CREATED THROUGH MAJOR,
MEDIUM AND MINOR IRRIGATION SCHEMES
ACREAGE IN MILLION HECTARES
DURATION
MAJOR
MINOR
TOTAL
i
*
Pre-plan period
1st plan 1951-56
Ilnd plan 1956-61
Hird plan 1961-66
Annual plan 1966-69
IVth plan 1969-74
Vth plan 1974-78
Annual plan 1978-80
Vlth plan 1980-85
Vllth plan 1985-90
VUIth plan 1990-95
IXth plan 1995-2000
Xth plan 2000-2005
9.7
12.2
14.3
16.6
18.1
20.7
24.8
26.5
31.0
37.5
• 45.5
53.2
58.5
12.9
13.6
15.8
17.8
22.3
26.1
28.8
30.2
22.6
25.8
30.1
34.4
40.4
46.8
53.6
56.7
54.5
113.0
Source : Anonymous (1984)
2.
IRRIGATION AND MALARIA
In certain pares
parts or
of cne
the country drought conditions may commonly
persi tst for 4-5 years, and the year 1987 witnessed one of the worst
drought
of this century.
In the eastern region excessive
floods
periodically bring devastation. This drought-flood- drought syndrome has
afflicted the country’s over all development. Agriculture often receives a
major set back due to uneven water availability in space and time. The
high yielding varieties
YV) and improved agricultural practices require
an assured water supply,
J therefore irrigation has always received major
emphasis and has been : ghtly included in the 20-point programme of the
Government of India.
3
Even
before
Sir Ronald Ross incriminated mosquitoes
in
the
transmission of malaria, there was remarkable unanimity of opinion of the
cause
and effect relationship between irrigation and malaria.
Russell
(1938)
has stated that " for example when Dempster in 1845 discovered the
usefulness
of the enlarged spleen in separating malarious from nonmalarious communities, he was a member of a commission investigating
unhealthiness associated with the western Jumna irrigation canal and stated
"All our previous knowledge and experience would lead us to suspect some
mischief from irrigating canals in such a climate as that of India,
especially if not e / p i <.• s s iy constructed so as to preserve the drainage of
the country and effectually to control the immoderate use of the water
attributed the extreme prevalence of fever in many places which he visited
to the rise of the spring level under the influence of canal irrigation".
Another quotation from Macnamara concludes that a comparison of the
statistics of towns in the irrigated and non-irrigated areas, that canal do
excercise a direct influence upon the prevalence of fevers in the direction
of their greater development and fatality. On irrigation Hehir (1927)
wrote " Like many sanitarians of India, (the writer) knows that the heavy
leakage from irrigation canals and channels is responsible for an enormous
amount of endemic malaria".
Covell and Bailey (1936) in reference to sind
stated " We consider that maintenance of this high level of malaria
incidence is largely attributable to conditions produced, directly or
indirectly, by the operation of the Lloyd Barrage Scheme". And finally we
quote
Russell
(1938) " Not only in India but in other countries this
failure has been evidence, so that there exists the tragedy of engineer
made irrigation malaria.
Colossus stumbling over a gnat".
In subsequent
years relationship of irrigation schemes to the increasing incidence of
vector borne disease incidence was well studied and documented.
In many areas of the country it was observed that opening of canals
brought malaria to healthy areas,
The commonly encountered reasons of
irrigation malaria are the rise in sub-soil water resulting in water
logging, poor drainage, minor engineering aberrations as leaky sluice
gates, seeping canal banks, borrow pits, defective distribution chambers,
improper delivery of water, poorly maintained canals, banks and beds,
absence of sufficient number of bridges, general water untidiness, absence
of controlled system of field channels, increased wet irrigation and lack
of coordination between different agencies (Rao 1945, Rao and Nassiruddin,
1945).
Some studies have been reported from India on the relationship of dam
construction and irrigation on malaria transmission.
In north India
irrigation has influenced the rise in ground water level in Haryana, Punjab
and Westen Uttar Pradesh.
As a result there are swamy conditions and poor
water percolation during rainy season in large irrigated tracts.
Breeding
of A. culicifacies is commonly encountered in such areas resulting in high
malaria transmission.
Similarly Santhanaur reservoir and its vicinity in
Tamil Nadu are responsible for half of rural malaria of the state of Tamil
Nadu. It is also noteworthy to mention that heavy concentration of malaria
is found in villages along the banks of the Pannaniyar river.
A.
culicifacies is the dominant vector which has found -extensive breeding
g rounds as a result of the introduction of irrigition .(Hyme and R aines h.
198U).
4
L
L
;
and extensive breeding
Canal irrigation provides most„ favourable
Sharma
and
Mehrotra
(1982) pointed out
grounds for mosquito proliferation. !-- - —
the
average
humidity
of
the
atmosphere thus
that irrigation increases 1'
making 1 the regions most conducive to mosquito survival. This produces a
thus enhancing
rate, thus
profound
effect
on the basic reproduction
••
(1982) demonstrated that villages bordering
transmission. Sharma and• Uprety
canals had very high incidence of malaria whereas in villages with tube
well irrigation the incidence ot malaria was very low.
Minor irrigation
systems (tubes wells etc.) if properly maintained are less hazardous than
the major and medium irrigation systems.
As a rule mosquito problems are
expected in the whole canal complex, the greatest risk being the minor
distribution channels which are most suitable for mosquito production than
the larger canals. The smaller the canal the greater is the chance for the
mosquito multiplication (WHO, 1982).
3.
;!
IMPACT OF WRDPs ON OTHER VECTOR BORNE DISEASES
Besides malaria, WRDPs have also influenced the transmission of other
Clyde (1931)
vector borne diseases e.g. filariasis, JE and dengue.
reported
from Sarda canal head works that "It is remarkable that at the
Culex mosquitoes were practically non-existent
very beqinninq of the work —
:
a certain
but with the opening of the forest and construction of the camps a
numerous,
— it being the
number began to appear. They never, however, became ---The
catch
10
culicines
for
every
500
anophelines.
exception to be able to
and
chief breeding places of these culicines were defective soakage pits
studies
by
the
Malaria
Research
Recent !
swamps contaminated with faeces".
that Culex quinquefasciatus
in the same area
have shown
Centre
populations have increased tremendously and as a result there is general
Added to this labour
mosquito nuisance in all semi-urban and urban areas,
and
regularly
drawn from filaria endemic areas of eastern U.P. and Bihar
Bihar
brings Wuchereria bancrofti infection and over the years, the area has
become endemic for filaria.
11
There is an ever increasing demand of water in almost all urbani areas
which are expanding haphazardly without adequate sewerage and sanitation
facilities. As a result water stagnates in open drains which have no
outfalls or in the low Lying areas. These are ideal breeding grounds for
reported
that
Culex
quinquefasciatus.
Kalra
and
Sharma (1987)
(1987)
reporte
breeding
of
Culex
mosquitogenic
potential
is
favourable
for
quinquefasciatus, the pestmosquito in Delhi, generated under pressure of
.
rapid urban growth has earned Delhi the nick name as "The city of TSul‘‘Lage
Lakes".
and as a
There is acute shortage of water in most urban areas containersresult
cisterns and other containers..
A.
water is stored in overhead tanks,
of
aegypti
the
vector
dengue
stephensi the urban malaria vector and Ae.
breeds profusely in the stored water.
As a result most urban areas of the
country are endemic for malaria and dengue epidemics have been reported
from several cities.
Irrigation has brought new areas under rice cultivation,
i s one of
staple food in the country and wild flooding is
irrigation practices.
Irrigation has brought new areas
5
Rice is the
the common
under rice
cultivation. Generally rice is rotated with non-rice crop.
A recent
development due to irrigation is that in many states like Karnataka, Tamil
Nadu and Andhra Pradesh 2 or 3 crops of rice are taken annually thus
providing extensive breeding grounds throughout the year.
The practice of
crop rotation i.e. rice followed by non-rice is beneficial in reducing
mosquito breeding.
Japanese encephalitis (JE) appears in sporadic or
epidemic form mostly in rice growing areas of the country. Between 1950 to
1978 outbreaks of JE were reported from Tamil Nadu, Karnataka, Andhra
Pradesh, West Bengal, Assam, Bihar, Uttar Pradesh, Pondicherry and Delhi.
It is estimated that during 1978-83 there were 2367 deaths due to JE, out
of a total of 7600 cases in India.
The vectors are the members belonging
to Cx. vishnui group, particularly Cx. tritaenioshnychus and Cx. vishnui
and they principally breed in rice fields (Sharma 1986 a,b).
• SECTORAL POLICIES AND DISEASE TRANSMISSION
Vector populations are regulated by a number of ecological factors,
of
this
The
interaction
of various
various developmental programmes disturbs
reduce
or
replace
vector
populations,
ecological balance and may enhance.
Impact of
o f sectoral policies on the vector borne disease situation in the
country is described below.
In the late 19A0s
Water Resource Development Projects - Irrigation:
4.1
India
was
22.6
mh.
Since
then she has
cumulative irrigation potential i n
and
created
an
irrigation
potential of
harnessed her vast water resources
The
irrigation
targets
have
been
set
at
113.5
nih
of which
about 68 mh.
'
"
'
irrigation
58.5 mh is from major and medium schemes and 55 mh from minor
states
In regard to health the National Water Policy (1987)
(1?
schemes.
"Project planning for development of water resources should as far as
be for multiple benefits based on integrated and multipossible,
disciplinary approach having regard to human and ecological aspects and
Maintenance,
special needs of disadvantaged sections of the society.
modernizat ion and safety of structures should be ensured through proper
In practice health aspects of WRDPs are
organizationa I arrangements."
completely ignored.
At present all major projects need clearance from the
Department of Environment which unfortunately does not examine projects
from the vector breeding view point. Breeding of insect vectors of disease
takes place in seepage water and water logged areas, due to poor drainage
and lack of proper maintenance.
The planning commission (1985) has stated
in ttie 7th five year plan document that existing irrigated areas where
salinity and water logged areas have been identified adequate drainage
facilities would be provided and it has become an important part of
irrigation projects.
It would be ensured that new project estimates would
include necessary drainage arrangements. Lining of canal system either
wholly or partially has been accepted as a necessary investment and it is
being taken up on priority basis and importance of this approach has been
accepted by the States.
In Punjab, Haryana and a few other states lining
It may be
of substantial stretches of canal has already been completed.
being
done
to
prevent
water
loss
and not
mentioned that lining of canals is I
such
as
the
prevention
of
mosquito
breeding,
for any health consideration.
In fact there is no awareness of this aspect of environmental degradation
neers.
among the planners and engineers.
The grassy margins all along the canal
To
and its tributaries
tributaries provide ideal breeding places for mosquitoes.
6
Jt
!
1
I
i
Ll
irrigate command areas water in the canal is released on rotation
basis,
This policy has been adopted c
on the recommendation of the World Bank
of equitable distribution of
policy
. water.
Water is released at 4 to 6 weeks
intervaI.
During the period when regular flow in
the canal is closed a
thin sheet of standing
water supports heavy mosquito breeding, an
site for proliferation of
ideal
A» cut i ci facies^
difficult, A weekly release of water would the control of which is most
ensure control of mosquito
breeding by flushing effect but this is never done.
It is notable to mention that the scheme
on Sarda Canal project
(Banbasa, U.P) was sanctioned in 1913
to
irrigate
12 famine prone districts
of Oudh. The work could not be taken
up
immediately
to World War I and
also' the fact that the requirement of the number of due
the
j
drainage outlets
to |prevent water logging in the command area could ...
not
command
area
could
not
be ascertained.
Thi s was considered essential because
following
the
opening
of Ganga Canal
in 1854 there
_ — .j was a rise in sub-so i I
water
and
water
logging
which resulted
in an increased incidence of
malaria.
It
is
noteworthy
to
mention that
drai nage in command area i —
was ensured before the opening of Sarda canal in
1929.
Malaria Control by spraying residual
y spraying residual insecticides changed the
outlook of planners and this
aspect of drainage did not receive
-----of
j
adequa t e
attention,
the rn Jdy‘'ramdn (]982) Nearly brings out the importance
drainage
from v^rC°7a?d area °f Mahl“Kadana project in Kheda, Gujarat. In this
area y ar round irrigation and multiple cropping of paddy has resulted in
« X
°”r “18 y~r period-
vvtihirrigation and poor drainage.
7
A better water management
system and
and continuous
management system
continuous monitorinq
projects by an mter-disciplinary team comprising of a'1t°rin9 of the
team comprising of
administrator would be the logical solution to the problem public health
to the
rather than
i?riqa;i™ebriPrayln9 WhlCh at present doe- f'°t produce the desired
impact.
ro
nrS ProsP'-‘''Ky by increasing agricultural production, Labour
mported for vartous developmental and agricultural works
The labour
force brings infection from malaria endemic areas and
settle
along the
water courses. In all such areas
<malaria incidence increases manifolds,
Wherever canal irrigation is being
encouraged the first disease to get a
(19R?? foot
fhOt ^hOtK ’S n,alaria- A study
Haryana
(1982) showed that villages with canal irrigation by Sharma and Uprety
, .........
i •
---— had
•— high malaria but
those with tube i
well
irrigation were free from the
the disease.
disease. Therefore
irrigation departments must ensure that canals are maintained
properly so
properly
as to prevent
water stagnation either in the irrigation system
system or in
agricultural fields. This neccessitates increased
of adverse health
J5 neccess1tates increased modernization, knowledge
ui aover^e Health impact, monitoring, p-*-—
maintenance
and...
provision of adequate
funds.
Even at the-present time no efforts .
’ '
are being made to study the
cause and effect relationship of vector borne diseases
■------- in
.,i
the
i rrigation
systems.
As a follow up of in-depth evaluation (1985) report of
NMEPZ the
Ministry of Health and Family Welfare
approached various ministries and
departments
concerned for creating_ an inbuilt infrastructure
to combat
malaria. Comments have been received from the Ministry of
Agriculture
(deptt.
of rura I department) and Central Water Commission
(systems
engineering). They have gi ven the following suggestions to
the
Ministry
of
Hea Ith.
7
i
i
I
i
)
(i)
Standing Committee (Advisory) may be constituted at national and state
levels to regulate the developmental projects/ activities under the
chairmanship of respective liealth secretaries. Members may be drawn
from departments like rural development^ water resources, irrigation,
public health engineering,
urban development,
agriculture
and
industries.
(ii) As malaria is very much connected with water engineering and water
development projects, there is a necessity to train engineers of
concerned departments.
Agriculture :
f\ study at the MRC showed poor relationship of rice
4.2
cultivation with malaria (Sharma 1987). Studies also showed that
culicifacies breeds in rice fields throughout the plains of India although
31 s proport ion varies from place to place. 1 he vector prefers sunlight and
therefore breeding is encountered in fallow fields and rice fields upto 6~8
weeks and breeding terminates when the plants attain a height of about 20
crus. The second vector A. fluv iat i I i s breeds in channels of rice fields
a I though breeding is scanty but occurs in some areas almost throughout the
rice cultivation season. With the coming of canal irrigation, two crops and
at many places in southern India even 3 crops in a year have become
common, thus the period of standing water in the fields has extended for a
very long time thus allowing continuous breeding of malaria vectors. Culex
quinquefasciatus the vector of filariasis also breeds in rice fields.
Besides Culex vishnui group of mosquitoes breed profusely in the rice
fields (Sharma 19867 1987). In
In recent years outbreaks of J.E. have become
very common.
.1
An
Population movement for agriculture is spreading the disease,
example may be cited of U.P. terai which is the green belt of U.P. In this
area before the control programme was launched C uIe x quinguet asc i atus
populations were negligible.
With the urbanization and poor drainage
quinquefasciatus mosquito populations have increased enormously.
Labour
for agriculture is imported from eastern U.P. and Bihar where the incidence
of filariasis is very high.
In the last decade or so the terai area has
also become endemic for filariasis.
Besides vast areas are under rice
cultivation, and Culex vishnui mosquitoes breed in these rice fields making
the area prone to JL epidemics (Sharma 1986).
At present there is no
policy to check population movement or migration and this is resulting in
the dissemination of vector borne diseases e.g. malaria and filaria to
areas free from the disease.
Plasmodium falciparum containment programme
(PfCP) has introduced a system of providing radical treatment to itinerent
labour moving into or' 'going out of north eastern region of the country and
this policy helped in the containment of drug resistant strains of Pf to
other areas (A.P. Ray personal communicjI ion).
WRDPs supply water to urban areas.
Urban Malaria :
In most urban
4.3
water
supply
is
not
properly
maintained
resulting
in
Leakage
of water
areas
In most
Similarly water storage results in mosquito breeding.
pipes.
water
allows
installed,
installed.
Stagnation of
towns drainage system is not
in
peri-urban
besides irrigation
breeding of a variety of mosquitoes.
As a result
for'
mosquitoes
to breed.
provides
opportunity
areas also
in
urban
areas
accounting
for
about
15-2OZ o f
serious
problem
malaria is a
(GOD
luuiiliy.
In
1971
72
Govt
of
India
of
ma
lai
ia
in
the
all cases
in 17
sanet i oned urban malaria scheme (UMS) in 153 towns distributed
8
states and 2 union territories (NMEP, 1986).
'
“The scheme
*
. r.
was implemented
in
a phased manner. Criteria for the selection
town --under the UMS; were :
-- of. --(i)
The population of the town should be >40,000. -
(ii) The Slide Positivity Rate (SPR) and Annual Parasite Incidence (API)
each should be 2 or more provided Annual Blood Examination Rate (ABER)
is atleast 10%, and
(i i i)Local bodies should have bye-laws directed towards vector control or
should
give an undertaking that they will adopt and implement byelaws within two years.
UMS is in operation in 127 towns. G0I accorded sanction for 10 new
towns during 1988-89 and another 38 towns are likely to be accorded
sanction during 1989-90. There are 203 towns covered under National Filaria
Control Programme (NFCP). Except in Kerala, Karnataka and Bihar, most of
the towns under NFCP are endemic for malaria. The towns in UP, Bihar,
Andhra Pradesh, Karnataka and West Bengal are also prone to dengue and JE
epidemics (UMS 1986) The following decisions are being implemented.
(i)
i
In urban areas separate programmes for vector borne diseases like
malaria, filaria etc are being amalgamated in to one programme of
vector borne disease control. Such a programme is already in existence
in Chandigarh (UT).
(ii) Building construction projects are progressing at a fast pace in urban
areas. In these cities A. stephensi breeding sites are being created
resulting in focal outbreaks.
Therefore it is suggested
that
construction project authorities should deposit 1% of the total cost
of construction work as health charges.
(iii)Bye-laws to prevent vector breeding are being enacted or extended
urban areas.
to
It is very early to predict the outcome of these
containment of vector breeding.
the
measures
on
The world commission on environment and development observed that "out
of India’s 3119 towns and cities, only 209 had partial and only 8 had full
sewage and sewage treatment facilities” (Our common future, 1987).
As a
result breeding of Culex mosquitoes in all urban areas of India is intense
and the situation is hapless.
I
Although bye-laws have been enacted in most urban areas to prevent
mosquito breeding but in practice these bye-laws are seldom used, the only
exception is Bombay. Table 2 provides data of malaria incidence in 4
metropolitan cities of India. Of the four cities the programme of Bombay
municipal corporation
is extremely well executed with the help
he Ip of
legislative measures, and malaria is under control. But a new township is
coming up in Thane district, about 20 Km south-east of Bombay named New
Bombay. Development of this area has been taken up to remove congestion
from Bombay. The area is under Panchayat (village council) and there were
no legislative measures to control malaria. As a result innumerable A.
f
9
stephensi and A. culicifacies breeding sites were created and there was
persistent malaria transmission and occasional
outbreaks.
However,
recently Bombay bye-laws have been extended to this city and since then the
malaria incidence has declined.
In Calcutta malaria cases are increasing at an alarming pace.
The
breeding of A. stephensi increased enormously due to potential created by
the construction of metro-raiI. A notable feature of mosquito breeding
sites was that large borrow pits created due to metro-rail work were not
filled up due to fear of unauthorised occupation ui u-i.u. Siagruiiii water in
the -borrow pits supported heavy mosquito breeding.
Besides Greater
Calcutta has a population of 10 million but malaria or mosquito control
programme is in existence in Calcutta town only which has a population of
3.5 million. In the remaining 6.5 million population although there are 38
municipalities but there is no malaria control programme.
Madras city contributes 55-60X malaria cases of the state of Tamil
Nadu and 70X of all cases come from urban areas. The vector is A. stephensi
which breeds in wells, overhead tanks, cisterns etc., although legislative
measures can be of great help in reducing vector breeding but these are
seldom used. Most overhead tanks are not mosquito proof, Further they are
inaccessible. and what is worse even today such faulty overhead tanks are
under construction.
r
i
Delhi is endemic for malaria and although bye-laws exist these are too
weak and not implemented. In Delhi there are several agencies which are
responsible for malaria control in their own areas such as the All India
Radio, Zoological Gardens, Jawahar Lal Nehru University, Indian Institute
of Technology,
Municipal Corporation of Delhi, New Delhi Municipal
Corporation etc.
Most of these institutions lack funds and adequate
Besides several
trained man power with skills to control vector breeding,
of
Delhi
do
not
coordinate
in any
agencies involved in development
meaningful manner, As a result sudden spurt of vector population and
Besides
Delhi is visited by dengue
malaria epidemics are common.
epidemics at periodical intervals, Uprety et al (1983) reports that on an
22.37. (range 7.4 to 527.) overhead tanks were breeding Aedes
average 22.3%
aegypti.
TABLE 2 :
S.NO. CITIES
MALARIA CASES IN FOUR METROPOLITAN CITIES OF INDIA
NO. OF MALARIA CASES
POPULATION
(IN LAKHS)
1984
1985
1986
1987
1988
1.
Bombay
82.27
2610
1371
833
1864
4073
2.
Delhi
75.19
38108
23495
23749
24455
14423
3.
Ca I cutt a
91.65
26056
18001
15723
8285
16465
4.
Madras
32.66
48523
51376
39197
30771
35459
10
/
A
5. POLICY ISSUES FOR CONSIDERATION
Vector breeding could be mitigated to a very large extent if
inter alia some crucial issues discussed below are addressed
adequately.
5.1 Inter-sectoral Collaboration: This is the most important issue which
is generally ignored, partly because at times eliciting intersectoral
collaboration is rather difficult. It should be adopted as a policy and
all programmes
should be coordinated at the Centre and district level
from the very beginning to contain vector breeding.
economy
5.2 Legislation: There are bye-laws to govern and regulate the»
health
viz..
Environment
and
protect
the environment and human
(Protection) Act, 1986, Factories Act, 1948, Northern Indian Canal and
Drainage act, 1873, Water Policy of India, 1987, Andhra Pradesh Public
Health Act, 1945, Tamil Nadu Public Health Act, 1939, Bombay Municipal
and Diu Public Health Act, 1985z and
Corporation Act, 1988, The Goa, Daman
I
Similar
acts and bye-laws have been
Goa Public Health rules, 1987.
Keeping
in
view
the background of vector
instituted in most states/UTs.
borne diseases and the importance of their containment, existing bye-laws
may be reviewed and those found weak should be amended and made more
stringent. Enforcement of bye-laws should receive utmost priority.
1
>
(WRDPs)
Water resource development projects
5.3 Water Management:
While
it
is
appreciated
constitute an important vector breeding sources.
that building of sound economy depends on harnessing water but this very
In all WRDPs
resource of prosperity should not produce health hazards.
hazards, In
be in-built.
preventive rather than curative aspects of health should
!Technologies are available to safeguard health but these are seldom
applied.
Wherever possible
possible lining
lining of
of canal
canal is
is aa good
good solution
solution to
to vector
Wherever
breeding, although initial investments are high. The cost of lining is
Irrigation as it exists
recovered in about 4 years by savings on water.
today is in a chaotic state with problems of uncertainty andI irregularity
in distribution. This leads to over irrigation and water logging, In many
areas rotational
rotat ionaI water supply (RWS) has been introduced and the outlet
Standing
command area is irrigated at fortnightly or monthly intervals.
intervals,
in
the
canal
results
in
profuse
vector
breeding.
Therefore
weekly
water
i rri gat j on or
r»r finchinn
chnulri be
bp adopted
adooted as a policy
oolicy to control vector
flushing
f lushing should
breeding. Importance of drainage in irrigation projects should not be lost
sight of, as is the case most often. In such areas vector breeding assumes
menacing proportions.
Besides a certain amount of funds should be
The
earmarked for the maintenance works in the WRDPs and command area,
irrigation system consisting of branches, minor and sub-minors should be
properly graded, maintained and cleaned of weeds to prevent vector
breeding.
It may be emphasized that health departments should be
responsible to monitor health related aspects of irrigation and corredtive
measures suggested by them should be mandatory.
; • should be contingent on the sound
5.4 Rural and Urban Water Supply:
drainage system for spent water IRegular Maintenance of both systems should
be ensured.
11
It would help to develop standard
5.5 Standard Designs, Prototypes etc.:
design/prototypes for water storage tanks. sumps building designs of
Only
Only those designs that have the
certain structures, f i xturesj etc.
should be permitted to be installed/constructed and
approval of the Govt,
this may be enforced by an act.
i
5.6 Labour
Migration/Settlements :: Labour movement from endemic areas to
Labour Migration/Settlernents
non-endemic areas
areas or
or Ilabour
home may disseminate? infection of
-------- returning
. —
:
parasitic diseases. It is necessary that itinerant labour is well protected
arrival and departure. Besides it
by administering radical treatment on
sited in healthy camps, away from
should be ensured that the labour is
r d H ; u j c.
with
proper
water supply and doraiouge.
mis
vector breeding sources
’
’
should
violation
should become part of the contractual agreement and any
attract penal action.
: Inland fisheries are encouraged through the fisheries
5.7 Fisheries
In many areas fish
ww
,.
w
..
w
cooperative
societies and private parties.
department i
;
are
not
well maintained.
culture is not done on scientific lines and ponds
\
•
_>
inland
fisheries
department
or private
for the -- -- ---i f should be made mandatory that
margins
of
ponds
are
deepend
and
deweeded
to ensure
enterprenuers
should
also
include
production
of
larvivorous
Fish culture
periodi cally.
fishes such as guppy or gambusia which are compatible with carps etc.
* i of
5.8 Agriculture
Agriculture :: There are various examples of ecological succession
This
may be
vectors and biological invasion of insect vectors of diseases,
as
deforestation,
aforestation,
deforest at i on.
the result of ecological disturbance such
digging of borrowpits, mining activities, change in salinity, irrigation
etc.
Thiss often results in the replacement of one vector species by
Tlii
In order to
another or
the introduction of new vectors in the» area.
or the
'
1
be
mandatory
to
evaluate
health risks
prevent such a possibility it should
beforehand and corrective measures Jincorporated in the plan.
r
6.
CONCLUDING REMARKS
There are no systematic studies in the country from the time WRDPs are
breedingpotential of different vectors of diseases and
constructed on the L
However some observations have been made
consequent disease transmission,
filaria and how they became endemic after the
on the status of malaria or
There
are
a variety of factors that promote the vector
WRDPs were created,
-- are conceived upto the end use. Some of
borne diseases from the time WRDPs
thecongregation of labour living under unhygienic conditions,
these are 1
population displacement, creation of borrow pits, seepage, submergence of
gricultural land, fishing improved agriculture as a
large tracts of
at
' canals etc., migration of population from endemic
result of opening up of
particularly
during
areas particularly during the
the harvesting
harvesting season,
season, etc.
etc. All these factors
r
_«•
-a systematic study
profoundly effect the pattern of disease transmission,
on
the
mosquito
breeding
and vector
is required on the impact of WRDPs
It
is
inportant
that
corrective
measures
are
borne disease transmission.
It is
construction phase of the project itself and
incorporated during the
implemented meticulously, Unfortunately at present 2 or 3X project money
curative such
— as opening of
meant for malaria ccontrol is being utilized in
rather preventive health services
This lecunae has
d i sponsori cs etc.
internal iofial
several
forums
and
more
recently
by
the
been pointed out at
12
group of experts during the in-depth evaluation of the Modified Plan of
Operation under the National Malaria Eradication Programme held in 1985 and
I quote ’’Project induced malaria h£s been a major problem.
With the
developmental activities gaining momentum under the 5 year plans, malaria
in developmental projects has been on the increase.
Power irrigation and
industry are the core sectors receiving highest priority in developmental
plans. In project congregation of labour drawn from different parts'of the
country living in adverse conditions, as well as in
mosquitogenic
conditions created by water logging/poor water management, provides ideal
conditions for malaria transmission.
There are innumerable examples of
irrigation projects where malaria was rampant during the construction phase
oi the dam as well as its canal systems.
Often even the maintenance phase
of these irrigation projects, malaria continues to be a problem because of
improper designing or failure in providing drainage facilities as well as
imperfect/ bad water management.
The committee while discussing with the
Central Water Commission was informed that it has prepared elaborate
guidelines for the irrigation projects which includes provision for anti
malaria and health measures.
Neverthless, the states, who are usually the
implementing authorities of the major and minor irrigation projects, failed
to implement adequately the anti-malaria and health measures. Often they
are satisfied in providing only a dispensary with a medical officer for
giving curative services. Preventive aspects are totally neglected. Many
times it is left to the health department of the state for providing these
facilities with their meagre resources”.
Above statement summarises the
totality
of picture of the WRDPs and how they are affecting the
transmission of vector borne diseases in India.
r
i
13
REFERENCES
1.
Anonymous (1984) Report of the working group on major and medium
irrigation for 7th plan 1985-90.
Government of India, Ministry of
Irrigation, New Delhi.
2.
Clyde, D. (1931) Report on the control of malaria during the
Canal Construction, Rec. Mai. Surv. India; 2: 49-110.
3.
n,in
Hyma, B. and A. Ramesh (1980). The re-appearance
Sathanaur Reservoir and Environs Tamil Nadu, India. Soc. Sc. Med. 14:
334-337.
4.
Jayaraman,
T. K. (1982).
projects
- A
case study
Envi ronment, 7 : 23-34.
5.
Kalra, N. L. and G. K. Sharma (1987). Malaria Control in Delhi- past.
present and future. J. Comm. Dis; 19(2): 91-116.
6.
National Water Policy (1987), Government of India,
Resources, New Delhi September 1987.
7.
NMEP (1986), Review Committee Report on Urban Malaria Scheme National
Malaria Eradication Programme 22 Sham Nath Marg, Delhi-110054.
8.
Our common future (1987), The world commission on Environment
and
Gro Harlem Brunltland (Norway),
Development.
Chairman
Oxford
University Press.
9.
Planning Commission Seventh five year plan 1985-90 Vol II Sectoral
Programmes of Development, Government of India, New De Ihi October
1985.
10
Rao, B. A. (1945). Malaria in Irwin Canal area Mysore State I. Jour.
Mai. Inst. India. 6(2) : 101-108.
11
Rao, B. A. and M. Nassiruddin (1945). Malaria in the Irwin Canal area
Part II. Jour. Mai. Inst. India 6(2) : 109-128.
12.
Russell, I3. F. (1938) Malaria due to detective and untidy i rr igat ion.
A preliminary discussion. J. Mai. Inst. India 1(4) : 339-349. Baker,
W. E, Dempster, T. E. and Yule, H. (1947) Report on causes of
Rec. Mai Surv. India. 1(1930), 2: 1unhealthiness at Kuranaul etc.
62, Macnamara (1980), Heir (1927) and Covell and Bailey (1936) also
Quoted by P.F. Rusell 1938.
13.
Sharma, V. P. and K.
(bond.) 298: 210.
14.
and
H. C. Uprety (19i2). Preliminary studies on
Sharma, V. P.
Ind.
J. Ma I. , 19 : 139-142
i rrigat ion malar ia.
Malaria: Impact of surface irrigation
from Gujarat,
India Agri cuIture and
N. Mehrotra
14
Sarda
(182).
Ministry of Water
Return of Malaria Nature
i .
L
15.
Sharma, V. P. (1986a).
Intensive agriculture and its impact on
vector borne disease. Proc. Indian National Sci. Acad., B 5(1) : 205208.
16.
Sharma, V. P. (1986b).,/ A comparison of vector control through
specia lized services, general health services and primary health
care/communi ty. VBC/PMO/SG/WP/86.9, 1-27.
17.
Sharma, V. P. (1987). The green revolution in India and ecological
succession of malaria vector.
Seventh annual meeting of the joint
WHO/FAO/UNEP Panel of experts on Environmental Management for Vector
Control, Rome, 7-11 Sept. 1987.
18.
Sharma,
V.P. and
H.C. Uprety (1982).
Preliminary
irrigation malaria Ind. Jour. Malariol., 19 : 139-142.
19.
Uprety,
H.C., P.K. Srivastava, B.N. Nagpal and V.P. Sharma (1987)
Mosquito breeding survey in urban Delhi.
Ind. Jour. Malariol, 20 :
79-82.
20.
WHO (1982) Manual on environmental management for mosquito
WHO offset publication No. 66.
i
studies
on
control.
1
15
f
Water Resources Development Policies,
Environmental Management and
Human Health
R. Bos
The international discussion on environ
ment and development sparked off by
the Brundtland report1 has resulted in a
renewed focus on how development
policies are often at the roots of environ
mental degradation and of a subsequent
deterioration of human health status.
In this context, the WHO/FAO/UNEP
Panel of Experts on Environmental Man
agement for Vector Control (PEEM) at
its ninth meeting (Geneva, 11-15 Sep
tember 1989) discussed policy issues as
they relate to the vector-borne disease
implications of water resources devel
opment projects2.
I
In principle, two types of policies can
be distinguished: government policies, at
the national planning level as well as in
the sectors responsible for water
resources development, which may
inadvertently have repercussions for the
health status of population groups
involved, and donor and development
agency policies, which essentially deal
v/ilh criteria and conditions for develop
ment assistance. Policies of the latter
category were discussed by type of
agency, ie. bilateral agencies, multilateral
United Nations (UN) agencies and multi
lateral development banks and funds.
As can be expected, a review of
government policies resulted in a wide
range of issues, even with the rather
limited sample of countries discussed. In
Egypt, where the link between irrigated
agriculture and schistosomiasis has long
been recognized, the government's food
policies (pricing of agricultural produce,
food subsidies and compulsory cropping
patterns) have left the agricultural sector
with little surplus for private investment.
Insufficient investment in system main
tenance has no doubt contributed to the
(C) 1990 Elsev’er Science Pub'-shers Ltd. (UK) 0169-4707^0502 00
creation of situations favourable to the
propagation of the snail intermediate
host. In India, the water resource sector
traditionally took into account health
aspects and this was reflected in its poli
cies. In the 1930s. for instance, the Sarda
Canal Project did not become oper
ational until proper drainage was ensured.
The objective of policies to provide
drainage for all irrigation schemes was
primarily to prevent water-logginginduced mosquito vector breeding. Such
policies were abandoned following the
introduction of residual insecticides for
vector control. Current policies in India
that have an alleged adverse effect on
malaria transmission include the policy of
rotational water release, which aims to
achieve a more equitable distribution of
irrigation water. This system leaves
pools of water in the empty canals during
the irrigation intervals, in which vector
breeding occurs. Policies aimed at live
stock promotion may have a detrimental
effect on human health if the domestic
animals play a key role in the epidemi
ology of a disease eg. pigs in the case of
Japanese encephalitis. The mechanics of
the latter example have been described
in detail elsewhere3/.
In some countries, policies aimed at
ensuring the incorporation of health
safeguards into irrigation projects have
been formulated. These address either
the decision-making processes at the
planning and design stage of a project, or
the establishment of effective institu
tional arrangements between sectors
involved. Examples were quoted from
the Philippines, where a number of
memoranda-of-understandmg regulate
the collaboration between the health,
irrigation and public works sectors5, and
from Ethiopia, where an initiative (the
Committee for Inter-institutional Collab
oration) has developed on an informal
basis. 1 he cxp/i icncc in I hailand shows
that legal requirements for cnvnonmental impact assessment are not always
a guarantee that human health impart
assessment is coveicd adcqiMt-'ly The
dichotomy between health and cn .-ii on
mental issues was observed m othei
aspects as well.
Policies should never be consideied
as definitive; as national and regional
priorities shift they may have to be
reconsidered and adjusted. In the Ten
nessee Valley of the USA. policies to
gear the design and operation of the
Tennessee Valley Authority's (IVA) big
reservoirs towards mosquito vector
control have been the basis for the suc
cessful elimination of malaria. Priorities
have now shifted to recreational reser
voir uses but the fluctuations in waterlevel. aimed at controlling vector breed
ing. interfere with these recreational
goals. Also, growing environmenta' con
cern with respect to wetlands has mad^
protectionist policies clash with ’rector
control policies II is clear th a
•
pi esenl-dci; > caUz. cc; i-.i-.a I •
may need adjustment, but tl '
■ v
reversing the successful achieve
■ : • ol
existing policies by doing so need'
1
properly weighed
It was concluded that, almoa •
r
exception, countries have exp.” ' • • '
problems in establishing cffecim
sector collaboration mined at r
environmental management me ;
development projects Allhou."
developing countries have mi ■
pi exedur <”» li’i cnvn (’iimrnl.r ••• ■ ’
assessment, then’ application hi. ; 1 ■
174
constrained by institutional and adminis
trative deficiencies, lack of trained staff,
political manipulation or lack of funds.
Bilateral assistance agencies direct
their efforts towards relief of poverty,
the sustainable development of natural
resources and protection of the environ
ment. They provide official develop
ment assistance in the form of loans and
grants, with a major element being tech
nical assistance. Most agencies have, in
the last co-.'p’e of years, embraced the
concept of sustainable development, but
in their programmes they still have to
find the mechanisms to bring this into
practice. The inherent long-term charac
ter of sustainable development, with its
requirements for monitoring, reviewing
and evaluating, conflicts with the usually
limited periods of donor support The
same intersectoral gaps found at the
national level in most developing coun
tries are also apparent in the structure of
most bilateral agencies. Health sector
specialists are involved in assistance pro
grammes aimed at strengthening health
services in recipient countries, but are
seldom involved in the assessment of
proposals for resource development
projects for their human health dimen
sion. It was also noted that many bilateral
agencies, in an attempt to visibly maxi
mize the benefits of their aid funds to
developing countries, decentralize staff
and expenditures. This trend, together
with the rapid turn-over of desk officers,
adversely affects the corporate memory
of the agencies in the complex matters of
environment and health during resource
development projects.
In the multilateral arena, the various
UN programmes and specialized agen
cies have all responded to the request by
the UN General Assembly to review
their policies and programmes in the
light of the Brundtland Report’s recom
mendations. This has resulted in a pleth
ora of position pajaers. policy statements
and resolutions of the various governing
bodies. These respond mainly to the
pressures of the conservationist lobby,
and they have yet to evolve to include a
more comprehensive concern for the
human dimension, in particular human
health. Thus the peculiar dichotomy
between environment and health
already mentioned is again observed.
The most promising trend in the multi
lateral agencies’ programmes is the
increased emphasis on monitoring and
evaluating the effects of development on
the environment and on human health.
The UN system, with its broadly based
programmes and continuous presence
in the member states, seems to be most
suited to help countries in developing the
I‘<ii<r.iiol(n'y lihtiy. v<»l (\t ik) 6. /Wb
human i esources needed for this task.
Multilateral development banks and
funds are in a special pqsition to pro
mote consideration of human health in
developrfient projects. Leaving aside the
possibility of including health as a compo
nent of an overall environmental pack
age to be negotiated at the appraisal
phase of a pi ojcct (cco-conditionality of
loans is a sensitive issue for most devel
oping countries), there is ample scope to
include hea th status guarantees in the
project design. In the case of potential
vcctoi-l >rne disease impact, cnvn onmental management measures included
m the des'g i should be complemented
by a strengthening.of health services
adequate to meet the needs of the new
circumstances. If a recipient government
is reluctant to accept the health compo
nent as oart of the loan, a grant for
technical assistance in this area from a
bilateral or multilateral agency could be
the solution.
The World Bank has taken the lead in
donor policy formulation by intiodtK ing
procedures that treat the environment
as part of a country's normal economic
and sector work. This will involve the
preparation of briefs outlining the princi
pal environmental issues of each country.
However, it is not clear to what extent
human health will be specifically con
sidered in the framework of these pro
cedures.
In the World Health Organization,
interest in this area is growing steadily.
The endeavour by the WHO/FAO/
UNEP PEEM is only one example. As a
major initiative. WHO has established a
high-level commission on health and
environment, which will assess the health
consequences of the environmental and
development crises. The conclusions
and recommendations of the com-
mission will constitute WHO's substantial
input into the 1992 UN conference on
environment and development. In
another initiative. WHO and the World
Bank are collaborating in studies on the
impact of economic adjustment and
development policies on human health
status. A broad literature review is ready
lor publication.
The analysis earned out for the 9th
PEEN meeting has been published as
document VBC/89.7 (Policies and Pro
grammes of Governments, Bilateral and
Multilateral Agencies and Development
Banks for Envir onmental Management in
the Context of Natural Resources. Agi iculture and Health Development)2 and is
available from the PEEM Secretariat.
WHO 1211 Geneva-27, Switzerland.
The panel's discussion, conclusions and
recommendations will be included in the
report of the 9th PELM meeting, to be
published in May 1990 as document
VBC/89.1.
Rcfcrcnccs
1 Wot Id Commission twi I nviionmrnt and
Development (1987) Our Comnion Future.
Oxford University Press
2 Mather. T.H. and Bos. R (1989) PEEM Rcfort
VhC f89 7. Woi Id I Icalth Oi g.imzation
3 Wada. Y. (1988) in Vector borne Disease Confro/ m Humans tfuouph Rice Apoecosystcm
Management pp 153-160. International Rice
Research Institute. Los Banos. Philippines
4 I cake. C.J. (1988) in Vector -txjrnc Drscosc Corifro/ m Humans through Rice Agroecosystem
Monogement pp 161 —171. International Rice
Research Institute. Los Banos. Philippines
5 Tech. C.L. (1987) m Selected Working Papers for
the 3rd-6th PERM Meetings pp 52-70. Docu
ment VBC/87.3, Wor Id Health Oi ganization
Robert Bos rs the secretary of the Joint WHO/
fAO/UNEP Panel of Exf>erts on Envhonmental
Management for Vector Control. World Health
Organization. 1211 Geneva-27. Switzerland
'/ 990, Nc Closed Season For Parasites’
I
A
.
G k
C1
I
(Cartoon by Ekkehart Lux of the Akademie der Wissenschaften der DOR. Am Tierp^rk 12S. 1136 Berlin, DOR.)
i
[
|
/
«
✓
I
Malaria Control by Engineering Measures: Pre-World-War-II
Examples from Indonesia
W.B. Snellen
I
>
I
7
Articles
/
Malaria Control by Engineering Measures: PreWorld-War-II Examples from Indonesia
W.B. Snellen
Malaria
I
Malaria is among the oldest recorded diseases. There are references to its intermittent
fevers in Assyrian, Chinese, and Indian texts that date from many years before Christ.
An ancient Chinese text, for instance, described the three malaria demons: one with
a hammer, one with a pail of cold waler, and the third with i stove, representing
the symptoms of the disease: headache, chill, and fever.
Around 400 B.C. in Greece. Hippocrates, who is traditionally considered the father
of western medicine, reported on intermittent fevers, writing that residents of low,
moist, and hot districts who drank the stagnant marsh water suffered from enlarged
spleens. (Malaria leads to an enlargement of the spleen.)
In ancient Rome, around the year 100 A.D., Columnella, in De Re Rustica (Rural
Matters), suggested the inadvisability of building a house near a marsh because ‘[the
marsh] always throws up noxious and poisonous steams during the heals, and breeds
animals armed with mischievous slings, which fly upon us in exceedingly thick swarms
..... whereby hidden diseases are often contracted, the causes of which even the physi
cians themselves cannot thoroughly understand' (Russell et al. 1946).
Columnella was quite right. It took physicians another eighteen hundred years to
discover that malaria was transmitted by mosquitoes. In 1880, in Algeria, the French
army surgeon. Lavcran, discovered and described malaria parasites in human blood.
Even then, it took another twenty years before the mosquito-malaria transmission
theory could be confirmed through the research of another army surgeon, Ronald
Ross, who received a knighthood and the Nobel prize for his work.
The Remans didn't need Ross’s discovery. They had already traced intermittent
fevers back to poisonous airs from swampy terrain and called the disease mal'aria
(bad air). The association of fevers with stagnant water and swamps led the Greeks
and Romans to practise various methods of drainage from the sixth century B.C.
onwards. Drainage to improve health conditions continued throughout the Middle
Ages in Italy, Spain, France. Holland, England, and elsewhere.
In the U.S.A., the transactions of the American Medical Association of 1874 were
largely devoted to a symposium on drainage as related to public health, especially
to the malaria fevers. But it was qnly after 1900 and Ross’s discovery of the mosquito
transmission that malaria control got a proper scientific base.
Basic Control Strategies
The greatest early-twentieih-ccniury demonstration of what can be achieved with ma
laria-control measures was furnished by William Crawford Gorgas, an American army
8
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Artii A’'
surgeon working in Panama. A French engineering company had been trying to build
the Panama Canal from 1881 to 1889. They failed because of enormous human and
financial losses due to malaria and yellow fever. In eight years, the French had lost
two hundred million dollars and five thousand lives. The Americans bought out the
French firm and started working on the canal in 1904, completing it in 1914.
Gorgas used three basic strategies:
- Medical treatment: every worker who got malaria was gi\en quinine immediate!}
and had to line up each day for the next six weeks to lake his pill;
- Reduction of vector-human contact: houses were screened; field construction
workers had to live in tents or railroad cars that were fitted with mosquito screen^:
- Reduction of vectors: Gorgas's men drained swamps and other breeding places if
they could; if they couldn’t, they treated surface water with a locally-developed larvi
cide.
:I
In ten years, Gorgas spent three million dollars to control malaria, with the following
results:
- Sickness among the work force dropped from 800 per 1,000 workers in 1904 to
40 per 1,000 in 1914;
- Death from disease in the same period dropped from 40 per 1,000 to 8.7 per 1,000.
It is estimated that Gorgas saved the U.S. some forty million man-days of sickness
and some seventy-one thousand deaths in the ten years of canal construction. President
Roosevelt promoted Gorgas from the rank of major to general; Oxford University
gave him an honorary Doctor of Science degree, and King George V of England made
him a knight [and shortly afterwards gave him a state funeral] (Russell et al. 1946).
Gorgas ran his malaria-control effort in Panama very much like a military opera
tion. This was possible because he protected a work force that had to follow his orders
and whose living conditions he could control. Of course, in a free society, you can't
force people to take pills if they don’t want to. And if people live in huts made of
bamboo, there isn't much point in screening the windows.
Because of the difficulty of implementing the first two strategies, the malaria-control
efforts in many countries at that time relied heavily on the third strategy: vector con
trol. And because there w'as no effective insecticide like DDT, the most important
vector-control measures were those aimed al eliminating or modifying breeding sites.
The importance of drainage and waler management can be seen in the publications
or. malaria control of that period:
- The manual, The Engineer and the Prevention of Malaria, by Henry Home, published
in 1926; it contains no less than four chapters on drainage;
- Practical Malariology, a medical book produced in 1946 by Russell et al. for the
U.S. National Research Council; it devotes a whole chapter to ‘Drainage and Fill
ing’ and describes many more water-management practices in other chapters.
y
AhkIc.\
The DDT Era
But in the handbooks on malaria control that appeared after 1950, there was no refer
ence to drainage or other engineering measures. When DDT became available the
praclicc-ol elmunatmg or modifying breeding sites and reducing man-vector contact
both by environmental management measures was replaced by a single method:
spiaymg the walls ol houses in malarious areas with two grains of DDT per square
Jmnally, this method produced very impressive results. So, in 1957, the World
Health Organization (WHO) set up a worldwide programme of malaria eradication.
India and Sri Lanka provided good examples of what could be achieved. The number
ol cases in India dropped from seventy-five million in 1951 to fifty thousand in 1961
Sri Lanka, with three million cases in 1947, had only twenty-nine in 1964 But just
a few years later, the malaria cases were being counted in hundreds of thousands
(Harrison I97S).
The programme failed because some ofthe species ofnialaria mosquitoes had des el
O|KaI les'slauce to mseelicidcs: they could now tolerate doses that were sure to base
killed previousgencrationsoflhesamcspecies. By 1980, oflheone-hundred-and-seven
countries where malaria occurs, mosquito resistance to insecticide had been reported
m s.xty-two of them. This meant that it was no longer possible to rely on the chemical
W
i iv 3 "’ost*u,locs- ln raclare now back in the situation that existed
before World War 11: not being able to rely on chemical control, we have to return
to an integrated approach and use all available methods.
4
I
1LR1 and PEEM
In 1981 in recognition of the above, WHO, HAO, and UNEP established the joint
.incl ol Experts on Environmental Management for vector control (PEEM). By
imging together organizations and institutions involved in health, water and land
development, and the protection of the environment, PEEM is promoting the use
ol environmental-management measures in-development projects.
<r
The role ofirngation and drainage engineers in the control of malaria and other vectorborne diseases is reflected in the technical publications produced through PEEM:
Drain^
CiHU,olhl Rice riMs- FAO Irrigation and
- Proceedings oflhe Workshop on Irrigation and Vector-Borne Disease Transmission.
international Irrigation Management Institute;
- Guidelines for Forecasting the Vector-Borne Implications in the Development of a
VVaicr Rcsmavex Projcd. ( DkiJi Version).
Manual on Environmental Managementfor Mosquito Control. WHO Ollsel Publica
tion 66.
(PEEM also issues a quarterly Newsletter
in English, I’rench, and Spanish
which
10
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Anii les
can I-. <. .laiia-j .'ree cf charge from the 1 ■IXM Secretarial. World Health Oreani/alion. 1211 < i.-nera 2". S\\it/erland.)
I
In I9S4 11 RI established the •Health and Irrigation Group', and later that year bc( , ’i inoratii"'Ccntreofl’EEM. The Group has been working on the forthcomcairv .■
ln„ hp,
H.canon
HeM. by !r J.de Wolf ant! Or J.M.V Oomen.
rie n r :• se of this publication is to create an awareness among desclopmen < . Is.
and
v-mal ers that irrigation development involves the risk of mtroducmg or
be incorporated
spreadme r ■ctor-borne diseases, and that preventive measures can
into ti'.e r . i.-m and operational procedures of irrigation projects.
Indonesit.n Experiences
As part of its collaboration with PEEM. ILRI is collecting and renewing literature
on malaria control under the colonial administration of the Dutch East Indies pnor
to 1940 - with special emphasis on measures related to land and water d^'°Pn1 '
This Indonesian experience is providing valuable mformat.on onaPPr°aC^
ization implementation, and effectiveness of environmental methods for malaria con
trol. This information has largely been forgotten, owmg to the discovery and largescale application of DDT and also because almost all the ongmal material had be
published in Dutch.
r ■
A
Malaysia
t
ICALANG
O
(SIBOLGA^ <■'
Kalimantan
<•10
J
Sulawesi
Irian Jaya
[jakarta)
.(BRENGKOK
C
~>X>. . . Java ’y7
C1ANJUR
*
<0 r
4
CIHEA
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I. loca'.k’r.
Mudies
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Early Sanitations: Sibolga
’ i control by technical measures - took
One <>r the citrlicsl sanitations i.c. malaria
place in Sibolga from 1913 to 1919. Sibolga was
t the administrative and trade centre
of the regency Tapanocli on the West coast of Sumatra (Hgurc I). Sibolga had always
been an unhealthy place. In 1912, the health situation had deteriorated to the point
where every household — European and native alike — was afflicted with malaria. A
Government doctor who was sent to investigate the malaria problem reported a
mortality rate for the year 1912 of 79.5 per 1,000 and a spleen index of 98. [The spleen
index is the number of enlarged spleens found in 100 examined persons.)
Table I indicates the breeding sites of Anophclinc mosquitoes and the measures
that were taken to eliminate them.
Table I. (Source: Nieuwenhuis 1919)
Location
Breeding sites
Control measures
Coastal swamp
Depressions al the edge of the
swamp, above the normal hightide level. 1 hey are reached
by seawater only al spring tide
and. after dilution with rain
water, create stagnant pools of
brackish water
Edge of the swamp
filled up above
,
spring-tide level;
grading and
levelling;
construction of
stone-lined
embankment
Town (seaside)
Stagnant rainwater in
depressions, due to poor drainage
(high watcrtablc and low soil
permeability)
f illing in
depressions and
raising surface
level Io 0.15 m above
spring-tide level;
surface grading
1:1000 towards
drains; construction
of drainage system
Town (seaside
and hillside)
Stagnant water in unlincd ditches
Replace open drains
with closed or semi
closed drains
Stagnant water in concrelclincd drains during periods
w ith low rainfall
Provision of narrow
central channel t j
take dry-period (low
Town
(hillside)
Stagnant water in depressions,
due Io seepage from the hills
Provision of hill
foot drains
River
Accumulation of brackish
water in sillcd-up river
mouth
River training and
construction of
piers
!
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J •
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Ariii k*
The total cost of the sanitation works amounted to DH.GaW (DH. = Dutch
H-r > at the I9‘,o price level, or DB.3.100 per hectare or 0(1.144 per inhabitant.
St^purison. labour wages in 1920 were about DU. 1 per day and the cost of r.cc
P„ LOCK, in 1911. and ta.W
>3 S
I"1’"
creased from 98 in 1912. to 50 in 1917, and to 1.9 m 1922 (Nieuwenhms 1923).
Species Sanitation
Sibok.. (te F»™a,
an «.n.P!e rfeompk.a saniw.inn: ,te me.snres kken
were aimed at all species of Anophehne mosqutloes. But tn 1911, Watson, working
in Malaya had found that not all Anophelines transmit malaria. He discovered that,
in areas where the forest had been cleared for rubber cultivation, malaria had disap
peared Clearin" the forest had destroyed the breeding sites of Anopheles umhiosu!:
which require shade, although it did not affect the breeding sues of other Anopheles
mosquitoes, which remained in abundance. It appeared that malana m th.s area was
"^VaBontished^ndonfst in 1913, and the malariologists there - the roremo^“m°n2
them beine Dr N H. Swellengrebel - immediately realized the importance of W arson
discovery‘instead of having to eliminate all breeding sues, they could control malana
s mnlv bv makin- the environment unsuitable for the local, proven, vector speuvs
SweHengrebel culled this ‘species sanitation’. Not only would spec.es samtat.on cost
i. .
k
I '
I
Figure 2. Spleen investigitlion
13
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Artir/r.\
/
much less than complete sanitation, it also provided the means to control malaria
in rural areas where the elimination of all breeding sites such as rice fields and irriga
tion canals would have Irecii impracticable.
Species sanitation depends on a knowledge of the local malaria vector and its habits,
so this was what Svscllcngrcbcl and his colleagues immediately began to study, 't he
first edition ol the handbook, Anuphcliiics in the Dutch East Judies, was published
in 1916. 'I he studies revealed that Anophelincs were not always as predictable as Wat
son had suggested. Only one species Anopheles sunihiicus - seemed to be a malaria
vector with pci leel iegiil.ii it v. u hercas other species transmitted malaria in some places
but not in others. Because ol this uiipicdiclabilny, csciy sanitation programme was
preceded In a local investigation. A booklet with guidelines for si.J) investigations,
prepared by Swcllcngicbcl and Schticffncr in 19IN, was distributed by the I Icallh Ser
vice to Government doctors throughout the Indonesian archipelago, l-’igurcs 2 and
3 have been reproduced from this booklet.
I
I'iguic 3. Cullcciing larvae
n
l J
Irrigated Rice and Malaria: Cihea Plain
I
lite Cihea Plain is a relatively dry plain in West Java, some three hundred metres
above sea level, brom 1X91 io 1904, the Irrigation Department spent about
.Dfl.1,000,000 on an irrigation system for some five thousand hectares. Upon comple
tion of the irrigation works, many people from other regions emigrated to the Plain.
In the first few years, productivity of the land was high and the irrigation water allowed
a year-round cultivation of rice. Water management in the area, however, was poor.
Even after the harvest, fields remained inundated.
I .
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14
LI
Li
I
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1
Il III II'
Bccairc ol il. ■ ■ ‘ .<'ijiinut>us submergence, soil Icrlility and fields declined. Also.
mal.ii i.i became a pi > dem. I he malaria vector in lheCihea Plain was Anopheles ucimitus. which p.-clom s' i nix bleeding places. Il does not breed in rice fields when the
1 ice planl> ha-.. i ■. /mJ a certain stage of growth because the plants produce too
the fields remain inundated alter the harvest, they become
much bhude B
les
1
he more fields declined and the more people’s health delcriexcellent biCKC’al
i he c real er the n umber of I ic Ids that remained unculliv a led
orated bec.u.^e • ■
rd the inme bleeding sites there were lor acomius. 1 he spleen
foi pai I o! the \. ■
i O-.e mortality rale increased to 60 per 1,000, which was three
index rose to
limes the axciacc ... wi etor Java.
To improve both the a uricullural and the health situations, a plant and water regulalion’ was introduced in 1919 (Mangkoewinoto 1923). Under this -regulation’, the
following were made mandatory:
Rice was to be cultivated only from I October io 31 May;
h rigalion water was to be supplied only during that period;
- All fields had to be drained immediately after the harvest.
To implement the ‘plant and waler regulation’, the Irrigation Department improved
the field drainage systems and the Health Department provided Dfl. 10,000 a year
J
tons/ha
5.0 r-
ha
2000
4.0 -
1500
3.0
1000
T
I
[
iA
1
'
/\
20 -
500
mortality rate (%)
average paddy production
* production (ton$/ha)
area of uncultivated
' 0 nee fields (tu)
%
60
50
- 40
/ \
- 30
- 20
- 10
0
o!__
1910
I
1915
1920
- 0
1935
Figure 4. Effecbofsaniiuiion mc.i>ures in the Cibea Plain
15
Artidex1
to dean the tertiary irrigation and drainage ditches. This task was normally done by
DKnr‘,r|niCrS;bul. I ,7 TerC
lo,,ger sumdcnl’y strong to do it properly. So. the Health
Dcp;n tnicnl paid the Irrigation Department to maintain the tertiary system
IXp.iiimcnl
•
■iriiic 4 shows how. after the introduction of the -plant and water regulation’ in
^N. nioftahiy decreased and agricultural productivity improved (Koorenhof 1933).
f igure 5 shows the Spleen indices for the children in the villages of the Plain for
i
CIHEA PLAIN
spleen indices (children)
c,
C/
t
©.
o
"■ * GlM.-iKJwrkyl.jlow
‘-’i
io Bar, Junu
I
Cipeu/eum
io Cianduf
I
■ I
Cirandjanggi rat >g
2'| Cuaiklpttgliilif
btxljOIMJI Hlitx-IMJ
I
r
Cl ANOUR
i.
PLAIN
:: ■u,i
Cibarengkok
I
Ctkondang
1
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[ ’
»pl««n indices (children)
in (he yc^rs
1819. 1922 end 1931
railway
riw
figure 5. Spleen indices (children) in IheCihcu Plain
L,
16
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Ariit
the years 1919. 1922. and 1931. Although this reveals significantly decreasing spleen
indices, in 1931 malaria still prevailed in the western part. This was attribtned to the
malarious areas in the Cianjur Plain, on the other side of the Rixer Cisokan. There,
no ‘plant and water regulation* had been implemented because the indigenous irriga
tion systems on that Plain did not proxide sufficient control over the waler. But. in
the light of the results achieved in the Cihca Plain, it was decided to replace the village
type systems with a ‘technical’ irrigation system - with separate canals for irrigation
and drainage - and to introduce a similar ‘plant and water regulation’. The irrigation
works for an area of 12.680 hectares started in 1937 and were scheduled for completion
in 1939 at a cost of Dll.460.000 [Jaarvcrski^ Genecskiuulh’ Lahoraiorium 1936).
Lagoons and Malaria: Calang
The success of species sanitation depends greatly on the correct identification of the
vector and its breeding site. This is illustrated by the example of Calang. a military
camp on the w est coast of Sumatra (see Figure 1).
In an effort to control malaria, the Army had begun filling in the swamps around
the camp in 1908. but the malaria persisted. In 1934. another army surgeon - called
Mulder - was transferred to the camp. After studying the malaria reports, he started
to wonder whether perhaps it were not the swamps that caused malaria, but the la
goons. These lagoons had formed in places where the discharge of the rivers was not
sufficient to push back the sand that had been deposited in the river mouth during
high tides. In the dry season, the sea built up a sandbar, which closed the rivers off
from the sea. The brackish water in these lagoons was a suitable breeding place for
Anopheles sundaicus.
Mulder started to experiment with laying wooden pipes through the sandbars to
drain the lagoons. Within four months, he had freed the camp of malaria. The wooden
pipes were then replaced by permanent steel pipes at a cost of Dfl.5,000. Quite cheap,
considering that the cost of filling the remaining sw'amps had been estimated at
Dfl 100.000. This illustrates that a lot of money can be saved by the correct identifica
tion of the vector and its breeding site.
Mangrove Forest and Saltwater Fishponds
The mangrove forests along tropical coasts used to have the reputation of causing
malaria. Early this century, in former British Malaya, millions were spent clearing
mangrove forests to protect villages and towns from malaria. Most ol that money
was wasted because the moxement of the tide makes a mangrove forest unsuitable
as a breeding site. However, when an area of mangrove forest is cut olf Irom the
sea by a road or a railway and there is no more tidal movement, an extrcmelx dangerous
breeding site is created. This can be prevented by placing sufficient culverts in the
road or railway to allow the tide to go in and out.
In Indonesia, mangrove forests were cut for the excavation of saltwater ll'hpondv
t7
4
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Articles
...... ....
-i... ..... ..............
i
fclironds. U.oy«.»» I»».K .......... . MK-. I. ■ -I-
i
r<lt 1I1C di^ra„
........ ....
D»“ -
u.g ....... .....
-
100 per I.O(M). Hvc times higherthe fishponds. The
KT
7- --
malaria problem in the fishponds, lc ri<
I
nrowth of water plants that
fish, which were vegetarian.
.i,v..k-nic exploitation' - reduced
-S?bSX Sn.25.oi.o~ ,O on.s.mw <»-.
“t“" 'ZoOoo rrodoeed ^sfoCory .«-> »<l was applied in many
I
places in Java.
I
JAKARTA
spleen indices
Indore and after sanitation
J A VA
SEA
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D
-
E \c
ffl H ffl
01
0
1701
^’7
p
/
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10'-'
/ rtf
•
UJ
•
i
ffl
I
‘*7
J
D
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ID >
■
spleen indices
in the ye«f«
1*
1917 and 1935
marine fishponds
->
river
city boundary
I ip,re 6. Spken indices in Jakaru. Uforc and af.cr the hygienic cxploilalion of saltwater fishponds
IK
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Articles
Saline Rice Fields: Brengkok
In the vill v’e of Brenekok. in spile of the hygienic exploilulion of the fishponds, a
, J > oXl «f nidana oealned a. I«)
7>. Th,
I
wa> ih U Ida monsoon rains were laier than normal that sear » ho. « hnald Mar rd
to rain, it was too late to plant rice. On the saline rice fields, ramwater was
and became brackish. Brackish, stagnant water on unculm a led rtce w ds s.
lent breedim’ site for Anopheles smnkhens. Once the cause had been .dent bed Ik
lent oreeomg
I
wlKllcvcr rCason - remained uncultisokiuon was qinie simple, vInn a ncu nua
vated the bunds were cut to prevent rainwater from inundating the field.
This shows that the prevention of malaria doesn’t always reqmre a substantial m-
I
vestmenr in Brenekok. it onlv needed a simple water-management measure.
The c iuse of the Brenekok epidemic was not identified through lareac finds b
0 m'a,S do«„r o, on m>.om«loSisi. bm by - e»Sincr. Krepers. ...................
500 m
;|
Laboenan
I
Brengkok
Limes:one hd!s
Lirr.estort runs
Ma^jcroeb
l
ma'ine fisK ponds
= road
—-— feeder canal
bridge
=:
. waste 'and
transition zone
dam
w.ne nee land
I
l igure - Poie.n.al bre..;.-,;.- sues lor
1
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swul.n.
neur tlxnlUge ol Hrergk..; >
I*
Articles
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/
Engineer oflhe Provincial Sanitation Office for East Java. Kuipers used meteorologi
cal data and soil characteristics oflhe saline rice fields to produce a ponding curve .
f rom the ponding curve, he derived a theoretical vector-density curve, which appeared
to correspond with the mortality curve of thirty-five days later (figure 8). This corre
spondence was taken as evidence that the breeding of Anopheles siiiukticus in the saline
rice fields caused the epidemic (Snellen 1988).
r
Conclusion
Irrigation
Irrigation and
and drainage
drainage engineers
engineers have
have an important role to play in the control of
malaria. Because oflhe single strategy during the DDT era, engineers in the last de
cades haven’t been consulted much on the control of malaria and other water-related,
vector-borne diseases. But because the single strategy no longer works, they can expect
to be called upon soon, as they were in the past.
I
I
in mm
700 r—
I
r
P- precipitation
E =* evaporation
600
.
P-E (19321
I
500
r
400
*
surface runoff iaA .xxxxxxxxs AX\Ly] '.x\ xsxssyyy »y->'syyt
si
saturated field —
100 ------
VECTOR DENSITY
Jan
number of
deaths/week
___
----
“I30
It
’Feb
Mar
Apr
- 20
MORTALITY CURVE
AFTER 35 DAYS \
------—1-'
•r-'
dtirdoul liclil—► 0k---- -----Dec
F
t\XXV
---------------------- theoreticalA—
200
increasing
soil moisture
ponding
depth
in mm
V*
I
I
May
Jun
:
Jul
- 10
- 0
I igurc X. Mortality curve, theoretical vector density, and the ponding curve in sidine rice fields near Brcngkok. derived from data on rainfall, evaporation, and soils
20
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References
Harmon. G. 1978.
Mulanu.und Man A Hisiur) of the
uncc 1880. Murraj. London
Home, H 1929. The Engineer and the Prevention of Malaria. Chapman and 11 all Ltd . London
Jaarvcrslag Genecskundig Laboraiorium over 1936. 1937. In: Mcdcdcclingcn dunst volkigczondhcid 2b{A).
p.262 (in Dutch)
I
i
Koorenhof. A C.. AHA Corls, and LJ. Vroon 1933'34. De Tjihca-vlaktc cn de resullaicn in dr laatsfc
15 jaren aldaar bcrcikt op assainccnngs- cn landbouwkundig gebicd. ’n. Landbou* (Buitcnzorg. Java)
9(9): 441-489 (in Dutch).
Mangkocwinoto. R.M.M. 1923. Assainecring der Tjiheavlakle. In: Mededeehngcn van den burgcrlijken geneeskundige dwnst >n b'ederlandsch-Indic 237-275 (in Dutch).
Mulder, J G.A. 1936 De malariabcstrijding it Tjalang, Wcstkust van Aljeh. In: Ceneeskundig tijdsihrift
voor Ncderlandsch-lndic. 76(30): 1864-1889 (in Dutch).
Nieuwenhuis. H.G 1919. Assainecring van Sibolga. Departement der Burgcrlijke Openbarc Wcrken Medcderhngrn cn rapporten Afdcling G Wcrken in het bclang van de gc7ondhcid.4.
Nieuwenhuis. H.G. 1923. Sladshygicnc door bodem-assainevnng In. De ^aitrsiaats-ingenieur. 11(7)
181-195 (in Dutch)
Russell. P.F.. L.S West, and R D. Manwell. 1946 Practical Malariulugy. Prepared under the auspices
of the National Research Council. W.B Saunders and Co.. Philadelphia and London.
Schueffner. W. and N H. Swellcngrcbel. 1918. Handleidaig voor het epidemialog'isih malaria-ondcrzoek ten
behoove van anibtenaren bij den burgclijken geneeskundige dienst. Albrecht & Co.. Wcllcvreden.
Snellen, W.B. 1938. A Malaria Epidemic caused by Anopheles ludlowi in East Java in 1933. In: Proceedings
of the Workshop on Research and Training Needs in the field of Integrated Vector-Horne Disease Control
in Riceland Agro-Ecosystems of Developing Countries. International Rice Research Institute. Los Banos.
Walch. E.W. and CJ. Schuurman. 1930. Zoutwatervischvijvers cn malaria. In: Geneeskundig-tijdschrifivoor-Nederlandsch-Indie 70(3): 209-234 (in Dutch).
Watson. M. 1921. The Prevention of Malaria in the Federated Malay States. E.P.Dutton &. Co.. New York.
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<
ROLE OF FISHES IK VECTOR CONTROL IN INDIA
V.P. Sharma
abstract
studies have shown
Production of larvivorous fishes is inexpensive a^ .t
utilises naturally
naturally occurring ponds and it could be linked
the. production of edible fishes for better economic gams
'proposal to establish a 50 acre farm of fishes for public health
for research and development would, strengthen application of
biological control of mosquito breeding in the country.
INTRODUCTION
widespread^!
^have^remained
mid-1970s there was widespread
resurgence
Besides large parts
Japanese
in 1973 have been visiting newer areas with vengeance. Similarly
dengue epidemics have been reported from various parts of t e
country.
The problem of urban malaria started to deteriora
concurrent
to
malaria resurgence.
The
National
Malaria
Eradication Programme (NMEP) of the Govt, of India is responsible
for the control of vector borne diseases.
The NMEP intensified
Vector control measures, with particular emphasis on malaria
control. The strategy of malaria control in rural areas was to
control malaria by residual insecticidal spraying whereas m
urban areas anti-larval methods were emphasized under the urban
malaria scheme (UMS). This strategy resulted in the curtailment
. of transmission in many parts of the country while in some
regions malaria outbreaks have been reported with deaths due t
malaria.
This has become a matter of serious concern. Beside
falciparum incidence has stabilized at about 0.5 million annually
to chloroquine in various
ar.d the parasite has become> resistant
1The
control
of
malaria requires more
states of the country.
At
the
same
time
massive quantities of
potent insecticides.
At the
■^^l
of
malaria
(e.g. DDT (50%) 21000
insecticides used in the control
malathion
(25%)
20,000
mt) year,after
mt,
BHC (50%) 37,000 mt,' 1--attract
public
criticism.
Insecticides
year
started
to attract
public
hazard.
--j
a
serious
health
contaminate the food chain and pose
Besides evolution of physiological lresistance in vector species
and harmful effects on beneficial fauna resulted in , control
...
failures (Sharma 1986a). The environmentally conscious scientists
demanded
C
--started
to question the wisdom of spraying and
During
Malaria Research Centre,
22- Sham Nath Marg, New Delhi-110 054.
1
I
■>
k
This lobby is becoming stronger
restricted use of insecticides,
control
by insecticidal application
day by day. Besides malaria c
and
there
are
instances
of the mis-use of
is very expensive
be noted that
meant
for
spraying.
It
may
also
insecticides
have
limited
life
span
as
the
mosquitoes
develop
inseciticides
and
eventually
multiple
resistance
develops
and
resistance
is
at
control
of
vectors
not
achievable
even
enormous
effective
' . Besides the cost replacement of
investments by the government.
malathion,
fenitrothion
or
synthetic
like
insecticides
invariably
prohibitive.
With
this
background
pyrethroids is
there was felt need of the malaria control organization m the
country to develop> alternative methods of vector control. It may
be noted that before launching of the Science and Technology
project, although fishes were recommended for biological control
under the UMS but sufficient stocks were not maintained, almost
anywhere in the country. Larvivorous fishes were kept m some
urban areas more for demonstration rather than for malaria
save few
a
It is noteworthy to
isolated instances.
control,
nowhere"in^the
country
fishes
were
applied in rural
mention that
malaria control programme in any meaningful manner.
—• In 1983 a strategy on the bioenvironmental
Field Experiments:
control of malaria was conceptualized at the Centre ana1 launched
for the first time in Gujarat. This
This field
field project
proiect was
was started in
.project
was
aimed
to study the
Nadiad, Kheda district.
The •ir_
•
control
of
malaria
in endemic
feasibility of the bioenvironmental
.
,
rural areas.
The study villages had extensive breeding grounds
-----In rparticular
for a variety of Anopheles and Cul^x mosquitoes.
In
malaria
Anopheles culicifacies, the vector of rural malaria was m
abundance. The vector was resistant to DDT, HCH and malathion.
Mosquito nuisance was unbearable and there was an outbreak of
In this area
malaria with deaths due to P.
falciparum,
methods
in
environmental
modification
and . manipulation
reticulata
)
brought
down
conjunction with Guppy fishes (Foecilia
incidence of malaria to low levels which was unattainable by
the 1.
residual spraying of DDT and malathion (Sharma,, 1987).
1987)., The
environmentally safe socially
alternate strategy
was found
environmentally
acceptable and cost effective (In-depth report. 1987).
<
L
i
$1
i
■
i
■
Simultaneously, while the field experiments in Kheda were^in
progress
plans were made to initiate similar studies in other
r
••
*
These projects were
country,
geo-epi d 'biological zones of the
of bioenvironmental control of
j
launchec to test the feasibility
areas
with
problems
related
to terrain,
in
other
malaria
and
socio-economic
and
cultural
aspects in
parasite
vectors,
industrial
areas.
Because
of
the
fact that
jrban
and
rural,
bioenvironmental
feasibi1 i ty studies showed promise in the
of mosquito
breeding and interruption
of
methods in
L. the
-- control
-.
.
transmission, this strategy was launched under the Science and
Technology project in mission mode, The project has the approval
of the Prine Minister of India and progress of work is monitored
Under this
by the Scientific Adviser to the Prime minister.
Project 9 field stations were opened‘ in UP,j Orissa, MP, Assam and
Tamil Nadu.
In all areas besides the environmental methods of
2
i
j
i
vector control, fishes were extensively used for the control of
< ‘ al. 1989).
mosquito breeding (Sharma et al. 1986," 1987, Singh et
first instance
instance local
local fish fauna were surveyed and
In the first
of indigenous
indigenous fishes
fishes was evaluated in the control of
potential of
1987).
mosquito breeding in different habitats (Sharmaet al.
Guppy
a
The two well known larvivorous fishes are exotic. The in 1908
native
of South America was introduced in India
1985). Gambusia affinis a native of Texas and widely
(Jhingran,
distributed in the world was imported in India from
Rao (Rao, 1984). ‘Guppy (Poecilia reticulata) and
by Dr.B.A.
Gambusia (Gambusia affinis) have been used in vector control
programmes for 5“to 6 decades and could be found widely occurring
in nature almost all over the country. Stocks of these fishes
were collected, multiplied and introduced in mosquito breeding
Experience of project scientists working in different
areas.
parts of the country on the role of fishes in the control of
Readers
mosquito breeding is being presented in this workshop.
advised
to
study
these
papers
in
original
to
get
the
feel
of
are
quantum
of
work
done
on
this
important
aspect
of
vector
the
control, and how far fishes can be used in the control of vector
borne diseases. Some innovative methods have also been
to reduce cost of mass production and distribution,
distribution.
Besid
larvivorous fish production has been linked with edible
production as an incentive to generate income for the village
communities (Gupta et al.1989). This income has been used in the
other
of
mosquito
breeding and in
schemes
of
control
of
mosquito 1__
1989).
environmental improvement (Sharma et al.
t
I
Future prospects : In India the main mosquito transmitted
diseases are malaria, filaria, Japanese encephalitis and dengue,
At present there are about 2 million cases of malaria, and of
these
about 60—70% malaria cases are transmitted by Anopheles
Anopheles
stephensi.
Remaining
culicifacies and 10-15% by ------~
or
8
vectors
which
transmission (10-20%) is maintained by other^7
A.'culicifacies is the vector of rural
are of local importance,
and peri-urban malaria, “"it breeds on ground in a variety of
habitats such as ponds, puddles, hoof prints, rice fields,
water
There
irrigation channels, seepage --— and marshy areas etc.
■
;
with
the
onset
of
monsoon
as
is a sudden spurt of its populations
ideal
breeding
habitats
in
vast
areas.
M
rain water provides iJl—1 1
stephensi breeds in wells, overhead tanks, cisterns and ram
water puddles.
Recent experiments havej shown
---- that fishes can be
annlied in the control of both the vector species.
Fishes couio
also be applied
in
the
control
of
other
malaria
vectors
but large
applied in the control of c—
scale field
application
may
require
selection
of
field application may r .
specific strains
and further
further research.
research.
In regard to .filari
,
specific
strains and
with 18
to its risk with 18
there are about 360 million people exposed toj-ts
million microfilaria carriers and- 8- million
1. --- with manifestationof
Cui ex
Wuchereriabancroft
_____ t
the
disease.
The vector of Wuchereria
i,
in all rural
quinquefasciatus breeds profusely
------ * in
, - polluted
,. water
to
newer areas
and urban areas and the disease is expanding
‘ iww, Vellore (Abdulcader, 1962) and U.P
around towns such as Lucknow,
mosquito also constitutes the bulk
terai (Sharma, 1986b). t This
responsible
for high nuisance in and
of mosquito population
3
is
around rural/ and urban areas.
Besides, a small focus
Bruqia
malayi
maintained in Kerala and some other pockets of
The mosquito
infection transmitted by Mansonia annulifera,
breeds in ponds infested with pistia plants.
Fishes used in the control of mosquito breeding in the world
are given in Table 1 and their distribution is shown in map 1
(Source, WHO 1982). Fishes have been used in India in the control
of mosquito breeding in a variety of habitats (Sitaraman et al.
1976, Menon and Rajagopalan 1977, Sharma et al. 1987) and ther
are strains of guppy fishes surviving for more than a decade in
polluted drains (P.B.
Deobhankar,
Personal communication).
Grass carps have also been used in the control of water weeds.
If introduced they not only clean up the vegetation from ponds
but keep the margins free of grasses and maintain the ponds free
of any veaetation growth.
The Japanese Encephalitis
transmitted by Culex vishnui group of mosquitoes and the disease
occurs in sporadic form.
The vector mainly breeds in rice
fields. So far there has been no effective method of the control
of mosquito breeding in rice fields that can be applied in vast
rural areas.
Of the many methods tested for the management of
vector breeding in rice fields fishes, hold good promise. Dengue
is transmitted by Aedes aeqypti.
The vector breeds in urban
areas in overhead water tanks
tanks,t
cisterns and a variety of
containers.
In
many situations fishes can control mosquito
In many
breeding if a proper monitoring system is established.
It is
noteworthy to mention that for the first time ever fishes were
used for the control of Aedes aeavpti
aeqypti in Havana
1----- at
- the turn or
century.
stagnant water all over the
In addition to disease vectors,
country produces enormous mosquito populations, These mosquitoes
Fishes can play
bite frequently and create unbearable nuisance,
thus
a
major role in controlling mosquito proliferation,
curtailing nuisance and disease transmission.
in various parts or
of tne
the country
Our studies m
counuxy have
iiavc shown
miywu that
in times to come larvivorous fishes will play major role in the
control of mosquito breeding to interrupt disease transmission.
insecticidal
This
conclusion
is based on the fact that
application would have limited role in the future in managing the
control of mosquito populations.
There would be a variety of
semi-permanent and permanent water bodies such as ponds, lakes,
wells, stagnant water pools, seepage water and rain water
collections which would produce enormous mosquito populations.
Besides poor drainage and drains with city waste water would
constitute another important source of mosquito production. Most
of these places can be tackled by the application of larvivorous
fishes (See Fig. 1 to 17 on the application of larvivorous fishes
in the control of mosquito breeding).
It is understood that no
single fish species can meet the requirement of a wide variety of
situations that exist in terms of mosquito breeding, but fishes
This would also be
could be selected for specific situations.
the cheapest method of vector control and produce long term
It is therefore
impact in suppressing mosquito populations.
4
l
U
U
u
L
necessary to intensify research on various
biology and its role in mosquito control.
i
r
aspects
of
fish
Genetic Resource Unit : Malaria Research Centre has surveyed
local fauna of fishes at its field stations located in various
the two exotic fishes guppy and
•
•
Besides,
parts of- the
country,
l
local
fishes
(Rasbora,
Oryzias, Colisa, Esomus) have
g ambus i a 1-- 1 1been found as good larvivorous fishes but require further stucues
on their biology
biology and application m the control o_ rosq_±to
breeding.
The Centre has intensified efforts to discove- :
for certain special situations such .as the rice fielo.s, slo;.’
novinc streams, river bed, canal, polluted drains, annual f^nes
that "can survive tne dry season through, the eggs wi.icn tcin
withstand dessication and start breeding with tne onset of ra^n,
fishes that can withstand extremes of temperature,
_v.r.j_o.i
e..io
salinity.
Unfortunately at present no indigenous fisn has oeen
shown to be suitable for above situations. Experience so ic.r nas
shown
that introduction of fishes wherever .they
survive
completely eliminates mosquito breeding,
provioeo
survive long enough, negotiate the grassy margins or penetrate
the weeds etc.
Fishes are highly successful ui the con_rox
nosouito breeding at low cost and without any adverse it?ac. on
the' environment such as are faced with me app ica._c.. o
insecticides.
The technology requires very sr^ll buoget
for supervision and transportation and the fishes ... evnatural ponds without any special care. Because or simp ic.uy of
technology and
and ease with which fishes car. be handle^ an.
introduced in water bodies communities can f-ayu najor xo.e .n
the maintenance
maintenance of
of hatcheries and distribution in rural e.rc
There; is
therefore
is therefore aa felt need and great scope fcr expio.t^t.o..
of fishes in vector control programme all over the country.
no centre
At present in India or elsewhere there is larvivorous
on
for
basic
and
applied
studies
exclusively devoted
a genetic
" J such
There is an urgent need to develop
fishes.
India
and
abroad
could
be tested
resource unit where fishes from
control
of
mosquito
breeding
under a
for their potential in the stresses.
Methods should also bvc
variety of environmental
'
„.i
and
maintenance
of stocks at low
developed for their distribution
larvivorous
fishes
and their impact
A systematic study of
cost,
be
of
great
valve
in controlling
on the environment could
epido-clinatlc
zones of the
mosquito breeding in different
country.
In order to achieve this objective it is proposed to
establish a 50 acre genetic resource-j unit on fishes for public
research
health at a suitable.place in the country with modern
have
satellite
The
main
unit
would
and expansion facilities,
field
stations where fishes> requiring special
centres at the f
--- —
The
— unit would perform
climatic conditions could be maintained.
the following functions.
Collection of indigenous; and exotic fishes from all over the
of genetic stocks. Exotic fishes will
world and maintenance
i------5
be imported only after obtaining clearance from the Govt. of
India.
2.
Research and development
3.
Reference Centre for larvivorous fishes
4.
Establishment of linkages both national and international
5.
Training
6.
Fish distribution in the country.
7.
Preparation of health education material.
8.
Consultancy services
l-i unit and field stations would carry
It is envisaged that the main
following
research
and
development activities.
out the 1
requirements.
(i) Biology of fishes and their nutritional
(ii) Maintenance of genetic stocks in acquarium and ponds etc.
(iii)Development of appropriate technology for mass production of
fishes in rural areas as well as urban centres.
(iv) Tests on the larvivorosity of fishes.
(v)
transportation,
Development
of methods for packaging/j
establishing
local
re-distribution
by
<
release,
and
hatcheries.
(vi) Establishment
fishes all
programmes.
r
of decentralized hatcheries of larvivorous
over the country for use in mosquito control
(vii)Selection of fishes or sub-species of known larvivorous
pHf
fishes that can withstand extremes of turbidity/
temperature, salinity etc.
(viii)Selection of fishes for weed control e.g.
and fungi/algae etc.
water
hyacinth
(ix) Composite fish culture.
(x)
L
Methods of manuring fish ponds and cleaning of
weed fishes.
(xi) Ecological
ponds
impact of the introduction of exotic fishes
regard to other fish fauna and non-target organisms.
It
from
in
The above proposal has been approved by the Govt, of India,
is noteworthy to mention that this would be the first
6
I
I
facility
of its kind
anywhere in the world.
REFERENCES
1.
2.
3.
4.
5.
6.
7.
r
8.
9.
10.
11 .
12 .
13.
(1962). Introduction of filariasis into
Abduleader, M.H.M,
Ceylon. J. Trop. Med. Hygiene; 65: 298-301.
us,
(1987). In-depth evaluation of the community
Anonymous
Vector Control of malaria project in Kheda
based Integrated
'
(Gujarat).
( 1989) .
ma,
and V.P. Sharma
Gupta,
D.K.,
R.C.
Sharma
Fish
Malaria
Linked
with
Edible
Bioenvironmental Control of
Ind.
J.
Malariol
.,
26
:
55-59.
production in Gujarat.
Jhingran,
Hindustan
V.G.
(1985).
Publishing
Fish and fisheries in
(India),
Corporation
India,
Delhi.
Mosquito control
Menon, P.K.B and P.K. Rajagopalan (1977).
indigenous
fishes
in
of
some species of
potential
765-771.
Pondicherry. Ind. J._ Med. Res. 66:
Published by the
Rao, T.R. (1984). The Anophelines of India.
Malaria Research Centre, Delhi.
(1986a). Malaria : Eradicating mosquitoes
Sharma, V.P.
Insecticides - Gujarat shows the bio-environmental
without
(and profitable) way. Science Age, 4(8) : 49-54.
Sharma, V.P.
(1986b).
Intensive agrjtSe--(
1986b)
on vector borne diseases. Proc.
National Science
Proc. Indian National
Academy, B 51(1): 205-208.
Gautam (1986).
R.C.
Sharma and A.S.
Sharma,
V.P.,
of
malaria
in
Nadiad, Kheda
Bioenvironmetal Vector Control
of
Ma
lariol
.,
2
3(2)
: 95-117.
district, Gujarat. Ind. J.
in
V.P.
(1987). Community-based malaria control
V.P.
Sharma
3(7) : 222-226.
India. Parasitology Today, 3(7):
Studies on
Sharma, R.C., D.K. Gupta and V.P. Sharma (1987). of mosquito
the role of indigenous fishes in the control
breeding. Ind. J. of Malariol ■ f 2 4 (1 1 : 73-77
Sharma, V.P., and R.C. Sharma (1989). Community based bio
environmental control of malaria
i------ in Kheda district, Gujarat.
”, Mishra, and O.P. Singh
Singh, Neeru, V.P. Sharma A.K.
of malaria in a tribal
Bio-environmental control
c
(1989).
Ind.
Inch J. Malariol. , 26_:
area of Mandla district, M. P103-120.
7
WHO
(1982).
informal
consultation on the use of fish
14.
mosquito octroi WHO/VBC/82-838, Fenera.
15.
Sitaraman,
N.L.,
for
(1976).
wells by
in grSiteF-sJaSIEad dty.InjU j. com.
S. fMa^ade^pphensi larvae
in
pis.t 8(4) • 315—319.
L
I
I
[
I
[
i
I
B
---- in
India mark
nark II hand pumps have been installed by UNICEF
many parts of the country to provide potable water ini rural
areas.
The installed sites have no provision of drainage
d
waater
(Fig. 1).
In
this
case
a
drain
was
prepared
and
1).
collected in a pit in Mandla district, MP (Fig. 2). This
site is used as hatchery for the production Poecilia
reticulata for the supply of fishes to nearby areas.
In Nadiad kheda district Gujarat village ponds are used for
the production of carps along with the larvivorous fish
Guppy.
The scheme was launched to encourage edible f ish
production as an incentive along with the control of
mosquito breeding and production of guppies for distribution
to other ponds.
Fig. 4 shows the collection of fishes from
a pond and Fig. 5 shows edible fishes ready for auction.
of
the
Health
education
is an important component
Fig.
6
shows
bioenvironmental control of malaria strategy,
a group of students visiting a laboratory in Nadiad field
station to study the role of larvivorous fishes in the
control of mosquito breeding and Fig. 7 shows a health
education camp delivering a lecture in Mandla village on the
application
of biological and environmental management
methods in the control of mosquito breeding.
xxd Gambusia
Ganbusia fishes are mass produced in village
Guppy and
A
pond
in Shahjahanpur village is being prepared for
ponds.
production of Gambusia fishes.
Weeds and predatory fishes
are removed and margins are cleaned and vertically cut (Fig.
8). Abandoned cement tanks are also used as hatcheries as
shown in Fig. 9 from a village in Nadiad, Gujarat.
10 and 11 shows a view of the nothing of Gambusia from
Fig.
pond in Shahjahanpur.
a village
1
Gambusia or Guppy fishes are collected from the hatcheries
and transported l.i
in a bucket for short distances (Fig. 12) or
truck
and
released in a variety of mosquito breeding
in a
such
an
underground
cement tank in Haldwani (Fig.
sites
13).
Fishes are used to control mosquito breeding in a variety of
habitats in rural and urban areas such as a well in
shahjahanpur (Fig. 14) a pond in Shankargarh, Allahabad
a drain in
(Fig. 15) a cement tank in Haldwani (Fig. 16) and
Mandla (Fig. 17).
9
Table » 1 KNOWN AND POTENTIAL LARV1VOROUS FISHES
/
ZONE AND COUNTRIES
SpairT, Morocco
Mediterranean and Near East
(including Afghanistan & Iran)
South-East Asia
FISH AND THEIR BIONOMICS
Family
Cyprinodonl idae
Cyprinodonlidae
Cyprinodontidae
Genus and Number of Species
Aphanius, 12 spp.
Valencia, 1 sp.
Aplocheilus, 6-7 spp.
Better Investigated Species
dispar, sophiae, rento
hispanica
lineatus,day i,blocki,panehax
Size (in cbs.)
5 - 10
B - 10
5 - 12
Dimorphism of sexes
Intermediate
Little
Intermediate
Type of spawning
On plants and substratum
On plants and substratum
On plants and substratum
Food
Omnivorous
Omnivorous
Carnivorous
Incubation period (in days)
7 - 10
12 - 14
14
Not resistant
Not resistant
Resistance of eggs to dessication Not resistant
Size of Fry
Of medium size
Big
Big
Rate of Growth
Rapid
Rapid
Rapid
Position of Mouth
Superior
Superior
Superior
Breeding Period
Year round
(depends on temperature)
Year round
(depends on temperature)
Year round
(depends on temperature)
Habitat
Streams, lakes, pools, ponds Streams, lakes, pools, ponds Lentic
1
CHEMISTRY OF WATER
6-B
6 - B
6- 8
dH
Hard water
Hard water
Moderate hardness
Salinity
Tolerant to sea water
Tolerant to sea water
Not very tolerant
Resistant
Resistant
Resistant
pH
o
Organic Pollution
[
I
—
I
TEMPERATURE
Max. range (in Deg. C)
B - 40
10 - 25
18 - 40
Min. (for breeding) (in Deg. C)
IB - 25
16 - 18
23 - 28
Very adaptable, hardy,
voracious feeders
Tolerate cooler waters,
voracious feeders
Surface feeders
REMARKS
L
L
S0U1H-LASI ASIA
SUUIH-EAS1 ASIA
50U1H-EAST ASIA
Family
Cyprinodontidae
Cyprinidae
Hen»i f bani ph i dae
Genus and number of Species
Oryzias, 10 spp.
Heniriianphus, Dern.o-ienys
Chela, Rasbora, Bar bus
(Punt ius), Darn o • Brae ti ydan i o,
Esomus.Osleobrama
Better investigated Species
melastiqma, javanicus
latipes
Many species in each genus
Few species
in every genus
Size (in cl)
3-4
2-10
4-10
Dimorphisit of sexes
Very little
Almost none
Little
Type of spawning
On plants, eggs in clusters
Un substratum
Viviparous
Food
Carnivorous
Omnivorous
Carnivorous
Incubation period (in days)
3-5
1-4
0
Resistance of eggs to
dessi cation
Not resistant
Not resistant
0
Size of Fry
Very small
Small or of medium size
Fig
Rale of Growth
Slow
Slow
Rapid
Position of Mouth
Superior
Terminal
Supericr
Breeding Period
Year round (depends
on temperature)
Rainy season
Year round
Habitat
Primarily still
water
Streams, stagnant waler,
rivers, lakes
Lagoons and
in fresh
reservoirs
7-9
6-B
7-9
dH
Hard waler
Soft
Ver y hard
Salinity
Tolerant
to salinity
Not tolerant
Tolerant to
sea water
Organic pollution
Resistant
Some can withstand,
but generally poor
Resistant
o
Max. ranges (in C)
18-40 : 1-40(laiipes)
18-40
IB-40
o
Min.(for breedingXin C)
23-28 :18-22(laiipes)
23-28
23-28
Remarks
Surface feeders
Surface and shoaling
f eeders
Surface feeders
ZONE AND COUNTIES
FISH AND THEIR blONOlUCS
r
I
CHEMISTRY OF WAI ER
pH
o
TEMPERATURE
I
/
South-East Asia
West Africa
West Africa
Family
Anabantidae
Cyprinodontidae
Cyprinodontidae
Genus and Number of Species
Macropodus ,Betta, Colisa
Trichoqaster, Trichopsis
Aphyoseition, 60 spp.
Roloffia. 20 spp.
Better Investigated Species
Many species in each genus
cal 1 iu run?, qardneri, sjost.-.'ti occidentalis, qeryi
Size (in cns.)
3-15
5 - 12
5 - 10
Dimorphism of sexes
Strong
Strong
Strong
Type of spawning
On plants, On substratum
Nests of water surface
Bubbles usually made by male
Food
Carnivorous
Carnivorous
Incubation period (in days)
2 - 3
1) 14
ZONE AND COUNTRIES
FISH AND THEIR BIONOMICS
Resistance of eggs to dessication Not resistant
2) 1 - 4 months
On plants, On substratum
Carnivorous
1)
14
2)
till 9 months
partially resistant
I
1) Partially resistant 2) resistant
Size of Fry
Small
Small or of medium size
Small or of medium size
Rate of Growth
Slow
Rapid
Rapid
Position of Mouth
Terminal
Superior
Supeiinr
Breeding Period
Year round
Year round
Year round
Habitat
Slow vara reservoirs and
in slow streams
Slow streams, pools, ponds
Slow streams, pools, ponds
6-9
5.5 - 7.5
5.5 - 7.5
dH
Soft and hard water
Soft
Soft
Salinity
Slightly tolerant
Some spp. slightly tolerant
Some spp. slightly tolerant
Organic Pollution
Very resistant
Resistant
Resistant
Max. range (in Deg. C)
20 - 40
15 - 35
15 - 35
Min. (for breeding) (in Deg. C)
23 - 30
20 - 25
20 - 25
Air breathing, easily
transported
Males may be territorial,
surface feeders
Males may be territorial,
surface feeders
CHEMISTRY OF WATER
PH
o
TEMPERATURE
REMARKS
ZONE AND COUNTRIES
West Africa
West Africa
West Africa
Family
Cyprinodontidae
Cyprinodonlidae
Cypr inodont idae
Genus and Number of Species
Epi platys, 30 spp.
Aplochei1ichthys, 50 spp.
Procatopus, 10 spp.
Better Investigated Species
fasciolatus, daqeti, chaperi
Size (in cms.)
3 - 10
2 - 6
5 - 8
Dimorphism of sexes
Strong
Little
very little
Type of spawning
On plants
On plants
On plants
Food
Carnivorous
Carnivorous
Carnivorous
Incubation period (in days)
14 days
10 - 18
10 - 14
Not resistant
Not resistant
FISH AND TrKlR BIONOMICS
Resistance of eggs to dessication Not resistant
gracilis
Size of Fry
Small
Small
Small
Rate of Growth
Rapid
Rapid
Rapid
Position of Mouth
Superior
Superior
Superior
Breeding Period,
Year round
Year round
Year round
Habitat
Slow streams, pools, ponds
Slow streams, pools, ponds
More rapid streams
6 - 8
5 - 7.5
6 - 8
dH
Soft and hard
Soft
Soft
Salinity
Slightly tolerant
Slightly tolerant
Slightly tolerant
Organic Pollution
Resistant
Not resistant
Not resistant
Max. range (in Deg. 0
15 - 35
16 - 30
16 - 30
Min. (for breeding) (in Deg. C)
20 - 25
20 - 25
20 - 25
Surface feeders
Surface feeders
Surface feeders
r
I
CHEMISTRY OF WATER
PH
0
TEMPERATURE
REMARKS
1^
1?
I
East Africa
East Africa
East Africa
ratiily
Cyprinodontidae
Cyprinodontidae
Cichhdae
Genus and Number of
Species
Nothobranchius, 20-25 spp.
Pachypanchax, 2 spp.
Tilapia, tore than 20 spp.
belter investigated
Species
guentheri, orthonotus,
patrizii, korthausae
playfairi, potalonolus
nilotica, mossarbica,
i:ze (in cui)
5-8
6-10
Inriorphisfr of sexes
Strong
little
lype of spawing
in substratum
On plants
on substratum, some carry
eggs in the mouth
Food
Carnivorous
Carnivorous
Carnivorous or
herbivorous or omnivorous
Incubation period
(in days)
20 days - 1 year (eggs
require drying)
14
Resistance of eggs to
des si cat ion
Resistant
. Not resistant
Not resistant
Size of Fry
Small
Of medium size
Large
Rate of Growth
Extremely rapid
Extremely rapid
Rapid
Position of Mouth
Superior
Superior
Terminal
Breeding Period
Year round
Year round
Well-known genus, species
variable
Habitat
Temporary ponds
Streams, pools, ponds
6-8
6-8
dH
Soft and hard
Soft and hard
Salinity
Tolerant
Very tolerant
Organic Pollution
Resistant
(Very tolerant to extremes)
Resistant
Resistant
16-30
18-35
10-40
20-25
23-28
18-28
"Annual" voracious feeders
Voracious feeders
Can be a food fish
ZONE AND COUNTRIES
• A,‘o' THEIR BIONOMICS
zilli
CHEMISTRY GF WATER
pH
6-8
o
)
)
}
variable, tolrerant
TEMPERATURE
o
Max. range (in C)
Mir*, (for breeding)
•'in Deg. C)
REMARKS
1+
Latin America
Latin America
Latin An.erica
Family
Cyprinodonlidae
Goodeidae
Poecillidae
Genus and Number of Species
Cynolebias, 20 spp.
Xenotoca, Goodea, Neoloca
Gan.busia, Poecilia, Girardir.us, Xipnophorus
Beller Investigated Species
belottii, adloffi, eleqans
X. eiseni
Hany species in each genus
Size (in cnis.)
4 - 12
6 - 14
2 - £
Dimorphism of sexes
Strong
Marked
Hales with gonopodium (anal fin in the
shape of lube)
Type of spawning
in substratum
Viviparous
Viviparous
Food
Carnivorous
Omnivorous
Omnivorous
Incubation period (in days)
2-5 months
(eggs require drying)
0
0
0
0
ZONE AND COUNTRIES
FISH AND HEIR BIONOMICS
Resistance of eggs to dessication Resistant
r
Size of Fry
Big
Very big
Big
Rale of Growth
Very rapid
Very rapid
Very rapid
Position of Mouth
Terminal
Terminal
Superior
Breeding Period
Year round
Production of fry about
50 days, ()L eiseni)
Year round, production of fry about
4 weeks
Habitat
Temporary pools
Streams, ponds, lagoons
Streams, ponds
6 - 8
6 - 8
6 - B
dH
Soft and hard
Hard
Hard
Salinity
Slightly tolerant
Very tolerant
Tolerant
Organic Pollution
Resistant
Resistant
Resistant
Max. range (in Deg. C)
5 - 40
5 - 40
10 - 35
Min. (for breeding) (in Deg. C)
18 - 25
20 - 25
20 - 25
Very vigorous
Very active feeders
PoeciHia and Gam bus la well known
I
CHEMISTRY OF WATER*
PH
0
TEMPERATURE
REMARKS
Source : WHO Ref. WHO/VBC/62.838 (Reproduced).
IG
i
>8
Med. and
Near East
Aphanius sp.
Valencia sp.
Cyprinodontidaepplocheilus sp.
Oryzias sp.
Cyprinidae
Rasbora sp.
Cnela sp.
Esows sp.
Barpus (puntius) sp.
Danio (Brachydanio) s:
Osteobrama codio
Latin America
S.E. Asia
J-?' /k
Hernirhamphus
-- Hemirhamphidae
(and other genera)
Cyprinodon
xipnophorous
Rivuius
Girardinus
Fundulus
Gambusia
Zenotica
/■,
E. Africa
W. Africa
Cynolebias
Austrofundulus
Nothobranchius
Pachypanchax
Tilapia"
' Anabantidae
;•
Epiplatys sp.
Cyprinodontidae
Aphyosemion sp.
Roloffia~sp.
Aplochei'lichthys sp.
Procotopus
NAP SHOWING THE DISTRIBUTION OF LARVIVOROUS FISHES
Source :WHO Ref. WHO/VBC/82.838 (Reproduced)
T9 “
Macropodus
Betta
Colisa
Trichogaster
Trichopsis
i
Indian J •jrn.il of Malariology
Vol 24. June 1987. pp. 73-77.
es on the Role of Indigenous Fishes in the Control of
Mosquito Breeding
R C SHAH MA' D K GUPTA1 and V.P. SHARMA 1
L
L
Rural malaria control is based primarily on the
spraying of residual insecticides to interrupt
transmission and treatment of malaria cases to
eliminate the parasite reservoir. The bioenvironmental strategy of malaria control being
employed in Nadiad lays primary emphasis on
control of mosquito breeding combined with
intensive fever surveillance. Among biological
control agents, fishes occupy the foremost po
sition due to their effectiveness in the control of
mosquito breeding, and the ease with which they
can be mass produced, transported and released
in a variety of habitats.
Fish fauna survey in 20 experimental villages of
Nadiad taluka revealed the presence of 27 types
of fishes. The fishes were identified by the keys of
Hora and Mukerji (1937) and Jhingran (1975).
These fishes v.ere found in temporary pools,
wells, a variety of ponds, seepage water, canal
and river etc Eight fishes were distributed widely
in many water bodies. Two species of top mi now
(Aploc'htiius lineatus and Aplocheiius panchax)
Accepted for publication: 12 February 1987.
’Malaria Research Centre Field Station
Civil Hospital
Nadiad-387001. India.
’Malaria Research Centre
22-Sham Nath Marg
Delhi-110054. India.
and guppies (Poecilia reticulata) were most com
monly encountered. In semi-permanent water
bodies 3 additional types of fishes were found.
Permanent water bodies had the richest fauna
i.e., 24 species of fishes, whereas the canal and
river yielded 19 and 16 types of fishes respectively
(Table 1). Though the fishes of India have been
studied quite extensively (Prasad and Hora,
1936) and there are several accounts of their
distribution, habitat and feeding habits eg.,
freshwater fishes of Bombay and Karnataka
(Gideon et al., 1937) this is the first account of
fish fauna of Kheda district. Of particular in
terest was the wide distribution of Aplocheiius
lineatus, A. panchax and Poecilia reticulata which
have been well documented as excellent larvivorous fishes and of these A. lineatus was
reported to be the fish most suitable for the
controf of mosquito breeding in a variety of
habitats (Hora and Nair, 1938; John, 1940).
During 1985 hatcheries established in the village
ponds in 20 villages produced enough guppies for
100 villages. Our field experience shows that
production of guppies is easy to accomplish.
Although top minnow fishes can also be pro
duced and transported with equal ease, these
fishes arc heavily preyed upon by a variety of
birds. This decimates their population in natural
habitats.
pl-5 3IT
(«(
03^ 3S-
library
AND
1* < OOCUMeiMTATION
\
<
UNIT
/
J
/
74
INDIAN J MALARIOL . VOL. 24. JUNE 1987
Table I. Ftsbes of stody villages
Species
Aplocheilus lineatus
Aplocheilus panchax
Ambassis nama
Chela bacaila
Catla catla
Cirrhina latia
Cirrhinus mirgala
Cirrhinos reba
Channa punctatus
Channa sp.
Glossogobius sp.
Heteropneustes fossilis
iMbeo rohita
Mastocembelus armatus
Mastocembelus pancalus
Mystus punctatus
Mysius seenghala
Notopterus notopterus
Ompok bimaculatus
Poecilia reticulata
Puntius sp.
Puntius stigma
Puntius ticto
Rasbora daniconius
Trichogaster fasciate
WatIago attu
Xenentodon cancila
Total
Temporary
Semi-permanent
t
Canal
River
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
8
Laboratory tests were conducted in plastic con
tainers (6 litres) containing 5 fishes each (except
Nctopterus notopterus [1 fish] and Mastocem
belus pancalus and Cyprinus carpio [4 fishes
each]), Four hundred IV instar anopheline lar
vae were introduced in the containers on the first
J; y. those that survived 24 -hours later were
Ci iinted and the number made upto 400 again.
The experiment lasted four days.
i
Permanent
Tests on larvivoracity revealed (Table 2) that
two fishes viz.. Mastocembelus pancalus and
Xenentodon cancila did not consume any larvae.
Poecilia reticulata fed on an average 40.5 larvae
per day while all other fishes consumed 60 to 80
+
+
+
+
11
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
■+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
19
16
+
24
larvae per day. Mysius seenghala consumed 132
larvae per day. Notopterus notopterus consumed
371 larvae per day which was the highest number
recorded among the 16 species tested.
For outdoor experiments cement tanks (80 x
80 x 75 cm) were filled three fourths with
water. Eight types of fishes were tested-on Culex
and Anopheles larvae. Mosquito larvae were
introduced in the tanks and their density was
estimated (average of 5 dips) daily for 6 days.
Results of outdoor experiments are given in
Table 3. The study revealed that feeding
capacity of fishes was reduced in presence of
i
I 1
I 1
LJ-
U
LJ
75
SHARMA ei ot INDIGENOUS FISHES IN MOSQUITO CONTROL
Table 2. Laboratory tests for larvivoracity
_
Number of mosquito larvae consumed
Fishes
Aplochalus lincalus
Aplocheilus panchax
Chela bacaila
Cyprinus carpio* *
Channa punctalus
Cirrhinos reba
Glossogobius sp.
Mastocembelus pancalus
Mystus seenghala
Notopterus noloplerus
Poecilia reticulata
Pontius sp.
Puntios ticto
Rasbora daniconius
Tnchogaster fasciata
Xenentodon cancila
Size in cms
2.5- 3.O
2.5- 3.0
3.0-4.0
2 0-5 0
6.0-10.0
-3.0-4.0
3 0-3.5
5.0-5.0
4.0-7.0
15.0
2.5- 3.O
3.O-3.5
4.0-5.0
3.0-4.0
4.0-6.0
21.0-23.0
Fishes
(Nos.)
5
5
5
4
5
5
5
4
3
I
5
5
5
5
5
5
Day I
Day 2
Day 3
Day 4
Total
Average*
400
396
400
400
399
391
260
0
386
360
350
320
400
260
400
400
400
382
327
0
396
367
100
363
400
400
4(X)
0
334
175
400
400
400
400
191
0
400
393
130
388
400
400
400
0
400
354
400
400
400
400
400
0
400
365
330
400
400
400
400
0
1534
1185
1600
1600
1599
1573
1178
0
1582
1485
810
1471
1600
1600
1600
0
76 6
59.2
-80.0
80.0
80.0
78 6
58 8
0
132 0
371.0
40.5
73.6
800
80 0
800
0
■ 400
400
400
0
• Average larvae consumed day/fish
•• Chinese or common carp
!
i
1
aquatic vegetation, although the margins were
clean and the fishes were able to reach all corners
of the tank. The larval density was reduced to
very low numbers in a 5 to 6 day period. Mystus
seengha/u consumed the larvae very quickly
followed by Puntius ticto. The known larvivorous
fishes Aplocheilus and Poecilia also reduced the
mosquito densities in ponds to low levels but
these fishes were found inferior to Mystus and
Puntius. In the absence of vegetation, the pre
ference was more pronounced for Anopheles
than Culex larvae. This may be due to better
visibility of Anopheles larvae which Goat on the
water surface. In the absence of vegetation, the
rate of consumption was; high and almost al) the
I trvae were eaten away in four days (Table 3).
Though Gambusiu has been credited for reducing
malaria transmission in the Ukraine (Gerbench
.md Laird. 196S). WHO (1982) and Hulbert
et al (1972) disfavour it because of its adverse
ecological impact. Fisheries departments in India
ilso discourage the use of Gambusia. It was not
found in rural areas of Kheda district, although it
,s used in the urban malaria scheme in Gujarat.
Gambusia was not studied in the present expertments
Field experiments were carried out to study the
impact of cleaning the margins of ponds. Larval
density was ascertained using a dipper 24 hours
before and after cleaning the margins and results
were compared against ponds w ith unclean mar
gins.
Results of field studies revealed that there was
considerable reduction in the larval density with
in 24 hours i.e.. average reduction in density
was 52%. 39% and 28% in January. February and
September respectively (Table 4). The impor
tance of cleaning the margins was therefore
clearly demonstrated and incorporated as an
importantI measure in the biological control of
mosquito breeding using fishes (Sharma and
Sharma. 1986).
Kheda district has a large number of ponds. Fish
fauna of these ponds is rich but these ponds also
support moderate to heavy mosquito breeding.
The ponds were never cleaned or properly main
tained by the village Panchayats. Although fishes
were being collected from these ponds and
occasionally auctioned by the Panchayats the
production was negligible. The ponds were
I
76
INDIAN J MALARIOL . VOL. 24. JUNE 1987
Table 3. Larvivoracity test of fishes ia cemeat tanks
Specie^
Size in ems
Larval density per dip
Fish Mos
es
quito
(Nos.) Spe
cies
Day 0 Day I
Day 2 Day 3 Day 4 Dav 5
Dav 6
An.
Cx.
An.
Cx
An.
Cx
An.
Cx
An.
Cx.
An.
Cx.
An.
Cx
An.
Cx
An.
Cx.
35.0
108
38.2
13.0
28.0
25.0
26.2
1.0
47.2
5.6
33.8
7.6
35.8
8.4
31.8
7.2
33.3
23.2
32.5
4.4
17.6
3.2
27.4
23.6
12.4
1.0
35.4
4.2
32.0
4.0
8.2
5.2
12.8
1.8
31.2
19.2
28.2
2.2
152
2.2
20.4
19.8
4.0
1.0
28.0
1.0
30.4
2.2
5.0
1.0
10.6
1.6
30.6
180
23.2
2.0
9.0
1.8
15.2
12.6
1.6
0.6
13 2
0.4
22.6
2.2
2.2
0.6
5.2
1.0
28.2
15.4
192
1.6
7.6
1.2
5.6
5.4
1.2
0.4
5.0
0
13.4
1.2
1.0
0
4.2
1.0
26.0
14.2
14 4
1.2
5.2
1.0
3.6
1.4
0.4
0
9.2
1.0
3.6
1.0
2.0
1.0
0
10.6
1.0
0
5.4
02
3.0
1.0
24.4
12.0
2.2
1.0
21.2
102
An.
Cx.
An.
Cx.
An.
Cx
An.
Cx.
An.
Cx.
An.
Cx.
An.
Cx.
An.
Cx.
An.
Cx.
54.0
67.8
28.4
53.6
43.6
60.4
74.8
48.2
51.8
51.8
54.2
48.6
39.2
43.0
63.2
666
52.4
66.4
28.4
62.6
5.6
33.2
20.2
52.0
2.6
1.0
164
36.0
360
43.5
124
35.2
8.2
45.4
50.2
64.8
19.2
53.2
2.0
3.4
0.4
32.2
0
0
3.0
22.4
21.4
40.6
0
4.6
2.2
15.0
47.6
63.2
7.2
506
0
0
0
29.0
2.4
18.2
0.8
19.6
5.6
38.2
0
6.6
1.6
8.0
2.2
1.2
0
46.0
61.4
0
0
(with aquatic ve^cu. oo)
Aplocheilus pancha
2 5-30
5
Channa punctalu.'
6 0-10.0
5
Cirrhinus reba
3 0-4.0
5
Heieropneusies fossilis
7.0-12.0
5
Mystus seenghala
4.0-70
2
Poecilia reticulata
2.5-3.O
5
Puntius ticto
4.O-5.O
5
Trichogaster fasciata
4 0-60
5
(witboat aquatic vegetation)
Aplocheilus panchax
2.5-3.0
5
Channa punctatus
6.0-10.0
5
Cirrhinus reba
3.O-4.O
5
Heteropneustes fossilis
7.0-12.0
5
Mystus seenghala
4.0-7.0
2
Poecilia reticulata
2.5-3.0
5
Puntius ticto
4.0-5.0
5
Trichogaster fasciata
4.0-6.0
5
Control
Control
cleaned and guppies were introduced to control
mosquito breeding. A scheme for the composite
culture of food fishes and prawns along with
larvivorous fishes was implemented
i
in 8 village
ponds. The ponds were thoroughly cleaned of all
94
44.8
47.0
types of fishes. Fries, fingerlings and juvenile
prawns purchased from the inland fisheries de
partment were then introduced and fish food was
occasionally provided for optimum growth. At
the end of one year the ponds were auctioned.
I
I
SI I AR MA < I hI
77
INDIGI NOUS 1 ISIII s IN MOSQUITO CONTROL
of poods on
Table 4. Impact of cleaning the margins
the* l»rv«l density of mosquitoes
Average larval density of positive sites
No of
Aiea
(1985)
Sites
examined
No
posi
tive
Results
dips
(Nos )
A. Experimental
24 hrs aftet cleaning maigins
Before cleaning margins
based on
I
11
Hl
IV
Total
3 43
1
II
JI!
IV
Total
118
0 44
2.87
0 42
0 27
0.82
0 10
0
0 43
0.09
0
0 12
1 79
0 71
4 24
January
February
September
48
37
66
28
17
41
133
85
213
2 36 0 79
1.34, 0 29
9.76 3 58
0 23
0 18
I 15
0 06
0
0 40
I 81
14 89
B. Control
January
February
September
23
14
20
22
13
20
117
65
83
3.35 4 I) 3.27
6.9 17 63 5 84
43 0 32.8 23 21
1 90
2 94
7 49
12 63
33.32 Nu change v.as observed in larva!
density
106 50
The production of edible fishes with indigenous
larvivorous fishes has motivated the village com
munities and for the first time composite culture
is being practised on a large-scale to control
mosquito breeding and improve the village eco
nomy. Eight village ponds were selected for food
fish culture out of which four ponds had to be
abandoned due to drought conditions and
large-scale poaching. Remaining four ponds
yielded about 10 tons of food fish worth appro
ximately Rs. 1 lakh.
Notes on the distribution . habitat and feeding habits
fishes of the Bombay &
of some of the fresh v.ater
Karnataka Rcc Mui Surv. Ind. 7(4): 245-251
(1937) 3 able for the
Hora. S L and I) D Mukeiji
*... ..
identification of Indian fresh uater fishes with de
scriplion of certain families and observationls on the
scriplion
‘
larvivorous fishes in
relative utility of the probable
3
Health Bull. No 12.(Govt of India Press. Nev.
India I.—....----Delhi).
Hpra. S L. and K K Nair (1938). Observation> on the
nutrition of Pancho* panchax (Hamilton) Proc
A. Nat
4
5.
i
acknowledgements
6.
Authors are grateful to Dr. H.B. Dave, Superin
tendent of Fisheries, Inland Fisheries Depart
ment, Government of Gujarat for the help
extended from time to time.
7.
8
9.
references
I
2.
Inst Sei- India. 4: 245-251.
Hulbert. S H . J. Zedler and D Fairbanks (197.). b.Cosystem alteration by mosquito fish (Cumbwm afjims)
predation Science. 175: 639 641
Jhingran. V G (1975) P^hes and fisheries oj India.
(Hindustan Pubbshing Corporation. India): 954
I »hn CC (1940). Observation on the utility of AptX /mArus (Cue & VAL) for mosqutto control. J.
Mat Inst Ind . 3(1): 67-80
Prasad. B and S L Hora (1936) A general review of
the probable larvivorous fishes of India Rec. Mai
Surv Ind . 6: 631 -648.
Sharma, V.I’, and R C Sharma (1986) Renew of the
integrated controlofmalariam Khedadtstncl. Gujarat,
(ndia. In Proceed,IC MR WHO Workshor on
Ge, bench. J B and M Laird (1968). Bibliography of
Communily Purucpooon Jo,
I rcmr kun.rol.
edited by VP Sharma (Malaria Research Centre.
papers relating to the control ol mosquitoes by l|ie use
offuh An annotated bibliography lor the years 1901
1966 Food and Ague. Org of UN. FAO Fuhene,
|C MR. Delhi) 59-84
W HO (1982). Biological Control of Vectors of Disease
Technical Paper No. 75: 70.
Gideon, P.W., P S. Gaonkaar and S.R Hagai (1937).
10
Sixth report of the WHO expert committee on vector
biology and control. WHO Tccii Rep. Ser.. 679: 39.
Indian Journal of Malariology
Vol 24. December 1987. pp. 175-180
Small-scale Field Trials with Polystyrene heads for the
Control of Mosquito Breeding
R.K CHANDRAHAS’ and VP SHARMA2
k
f
I
vations made between February 1985 and Feb
Wells and overhead tanks are the principal
ruary 1986 arc summarised in thi?» communi
sources of mosquito breeding in urban and semication.
urban situations. In villages around Delhi, wells
are the major sites for mosquito breeding. Most Well surveys were undertaken in South Delhi
of the wells are unused and abandoned. Culex
(Basantpui area) and West Delhi (Gommanaquinquefasciatus is the predominant species as hera and Pindiwala Khurd areas) in January
sociated with well breeding. Other species found
1985. All wells found with mosquito breeding
breeding in wells were the members of C vishriUi
were numbered. The population of immatures in
group. Anopheles stephensi and A cultcijacies. the wells wa> sampled using a galvanized bucket
In urban situations, overhead tanks are of con
(5 litre capacity). A total ol 5 dips were taken
siderable importance as far as mosquito breeding
from each well. The anophelines and culicines
is concerned. In Delhi city almost every locality
were then separated and counted instarwise in
has an innumerable number of overheadtanks
number of pupa£ coUected
enamel trays. —
. .
and the mosquitoes found in associa
recorded.Polystyrene beads
were also recorded.-Polystyrene
beads were then
overhead tank breeding are the vector
introduced
with
the
help
of
a
bucket (16 litre
haemorrhagic introduced with the help of a l_
capacity) and allowed to form a
fever. Aedes aegyptL
Generally two buckets of beads (about 650 to 700
introduced into each w ell of about 1.5
1"
“
SSXiin
m diameter and in bigger wells 2.5 to 3 buckets of
control of mosquito breeding in unused w ells and
beads (about 800 to 900 gms) were introduced.
overhead tanks, the effectiveness of Expanded
Polystyrene beads (EPS) was evaluated in Delhi
The overhead tanks located in Ayurvigyan Na
and its neighbourhood. The results of the obsergar. R.K. Puram (Sector 9). INA Colony and
Pushpa Vihar areas were surveyed during
AcceptedJor publication 28 August 1987
June/July 1985 and numbered. Thereafter, the
‘Malaria Research Centre (Field Station)
entrance of the ingoing pipe was covered by a
1807. 18th Street
small piece of steel mesh to prevent the entry of
I Block. Anna Nagar West
beads into the pipe line. About 200 gms of
Madras 600040. India.
2 Malaria Research Centre (ICMR)
polystyrene beads were introduced into each
22-Sham Nath Marg
overhead tank.
™ «*«
Dclhi-110054. India
bigger
/
176
INDIAN J MALARIOL.. VOL 24. DECEMBER 1987
Post-treatment observations in wells were carried
out at weekly intervals. After taking one sample,
the beads drawn along with the bucket were
removed with the help of a metal strainer and
transferred to an enamel tray and the larvae
(instarwise), and pupae were counted. The larvae
(instarwise) and pupae which were found dead
were also counted and recorded separately. The
beads collected from all the five samples were
returned to the well.
The post-treatment observations in overhead
tanks were also carried out at weekly intervals.
The breeding was checked with the help of an
aluminium spoon (60 ml capacity) or an enamel
bowl (150 ml capacity). Generally three dips were
taken. The contents were transferred to an
enamel tray, beads separated carefully and then
checked for the presence of immatures.
The EPS beads were introduced into 42 wells of
which 25 were found breeding exclusively culicines and the remaining 17 wells had mixed
breeding of anophelines and culicines at the time
of application. The EPS beads were introduced
into eight wells each during February 1985 first
and second fortnights respectively, six and three
wells in March first and second fortnights re
spectively. nine wells in July second fortnight and
five and three wells during the first and second
fortnights of August respectively. A total of six
wells served as co itrol. The post-treatment ob
servations were continued for a period of 46
weeks in wells treated during the first and second
fortnights of February 1985; for 42 weeks in wells
treated during :he first and second fortnights of
March; for 26 weeks in wells treated in July
(second fortnight) and for 22 weeks in wells
treated during the first and second fortnights of
August 1985. However, in the presentation of
post-treatment data, the results of weekly col
lections have been computed and the monthly
average number of immatures per dip sample
with range for the entire observation period from
February 1985 to February 1986 have been given
I
I
i
in Table 1 with density of larvae and
recorded in the control group of wells.
EPS beads were introduced into a total of 879
overhead tanks in Ayurvigyan Nagar, R.K.. Puram and INA Colony. Pushpa Vihar with 476
overhead tanks was retained as control. The
results of overhead tank survey are furnished in
Table 2.
There are inherent difficulties associated in the
effective control of mosquito breeding in wells.
While a larvicide requires weekly application,
larviciding is a difficult operation in wells be
cause of long distances between the wells and
difficulties in reaching them during the rainy
season. The present study on the application of
EPS beads has shown that there was a drastic
decline in the density of culicine larvae and pupae
in the successive weeks after treatment. Further,
the EPS beads suppressed adult emergence as
seen by considerable mortality of pupae and
emerged adults. In case of anophelines, breeding
was detected in 6 of the 8 wells treated in
February 1985 and one of the 3 wells treated in
March 1985. Following application of beads, the
anopheline breeding was found to continue for a
period of one to three weeks except in two wells
where the breeding was recorded for a period of
19 to 22 weeks after application. In all these wells
only the early instars were encountered. Fourth
instar larvae could be detected during 7 out of 17
weekly observations. However, no pupae could
be detected during the entire period of obser
vation. Based on laboratory studies (Sharma,
1984) it was observed that application of EPS
beads at the rate of 1.0 gm/m2 produced high
larval and pupal mortality in Cx quinquefasciatus, A. culicifacies and A. stephensi. In a field
study, Sharma et al (1985) found that EPS beads
were effective in the control of mosquito breed
ing in biogas plants and wells in Nadiad taluka.
Kheda district, Gujarat. The results of the pres
ent study support the observations of the above
authors. The method has several advantages, a) it
“I
1 j
1
j
1
t }
I
J
1
J
I
Table 1. Effect of polystyrene beads on mosquito control in wells
Months—post treatment
February 1985
study
Number of
collections
Average No. of
immatures
1-111
Range
IV
Range
Pupae
Range
March 1985
treat net at
Number of
collections
Average number
of immatures
I-1II
Range
IV
Range
Pupae
Range
Feb
19X5
Mar
Pre
treat
ment
Post
treat
ment
16
65
51 3
458 0
0 9151 0-1057
38.0
5.2
18-587 0-344
0.09
75
0-10
1-267
Apr
May
Aug
Jul
Jun
Sept
Nov
Oct
Dec
Jan
1986
Feb
n
5z
c
60
66
28.0
0-1573
0.445
0-71
0
0
17.6
0-1246
0.44
0-523
0.002
0
0.025
0-2
0
0
0
0
60
61
51
54
2.5
0-353
006
0-11
0
0
0
0
0
0 02
0 6
0 006
0 1
0
44
14
21
0
0
5
5(✓)
16
>
2.6
0-225
0.095
0-10
0
0
40
2.67
0-626
0 143
0-10
0
20.6
0-833
0.73
0-89
0
9.05
0-517
0
0
524.2
306-7632
66 5
28-1441
5.2
0-127
tn
I
5
z
Pre
treat
ment
9
z
o
m
r
c
35
32.2
0-1801
0.9
0-149
0.001
0-1
42
1.7
0-158
0.02
0-3
0
36
36
>
z
o
40
37
20
18
12
26
II
0
3.8
0-148
1.6
0-128
357.3
0-920
3.0
0-285
0
6.3
0-343
0
0
9.9
0-453
0.006
0-4
0
0.07
0-3
0
0.08
0-15
0
0
0
004
0-7
0
0
0
0
0
0
0 001
0
0-1
contd.
>
z
*
C/5
Table I. (contd.)
Months—post treatment
Feb
Mar
Apr
May
Jun
1985
Jaly 1985
TreatMeat
Jul
Aug
Prement
PoMtreat
ment
9
37
tre.it-
No. of
collections
Average number
of immatures
l-lll
Range
IV
Range
Pupae
Range
Sept
Oct
Nov
Dec
Jan
1986
Feb
z
o
>
36
2
25
16
II
21
7
X
64.6
4 2
0-1362 0-481
' 9 15
0.26
0-215 0-24
1.6
0.005
0-35
0-1
0
(l
0
0
0.1
0-12
0.008
0-1
0
12 0
0-874
7.0
0-55
0.04
9.2
0-201
0
0
0-220
0.03
0-3
0
2 34
0 82
0
0
0-3
l-lll
Range
IV
Range
Pupae
Range
5r□
m
n
CONTROL
No. of collections
Average number
of immatures
>
rn
21
461.5
40-6675
80.0
3-1438
11.3
0-269
25
664.8
35-13941
101.5
0-1369
9.2
0-275
27
70.0
0-3140
17.0
0-854
3.0
0-145
26
1.45
0-61
0.4
0-38
0.12
0-11
24
27
37.2
51.5
0-2346 0-4064
7.6
6.23
0-722 0-727
3.0
2.0
0-303 0-188
21
IK
9
9.7
0 384
6.8
0-358
0.044
0-4
0 03
0-3
34 0
75 0
0-915 0-2454
0
15.0
0.83
0-43
0.2
0-18
K
0-423
0
2.5
0-73
20
X
19d n
0 5X|<
119 (i
0-4'7
466 5
0-9920
14.0
0-196
24
2 25
0 8|
0-55
2
□3
rr
( IIANDRAIIAS AND SHARMA
179
l.l’S IN WI LLS AND TANKS
labk 2. EffiCBCj p( El’S beads in overhead tanks
Ayui vigyai)
Aic.i
R K
I'm.iin
1 NA C olony
Pusb.pa Vihar
((. Oilliolj
ISafal
276
476
H7
172
I
11
III
l\
(I
0
72 I
72 0
| 4->
88 12
I
6(> 3
52 3
80.6
143/0
8 0/0
Numbct <•! tank-' ticatcd
J..,) I**?. 5
Numbc: of taiik* sampled
positive
Week
48 7
A jgu-»t
Week
96,4
11
161,2
IH
'1V
Scptcinbct
Week
1
86 0
80,4
331/25
11
60,0
247.10
96.12
111
116/0
1 16, I
125,8
65,19
IV
141/0
96 2
1
172/0
144/1
249/30
167,2
251/1
414,14
201,1
IV
157,7
68,1
157/0
223/0
2 80/3
249,4
465/7
146,4
318/3
37/0
270/2
472/7
172/0
276/0
(Alobc!
Week
II
111
199,1
November
Week
I
286/3
II
186/0
111
185/0
IV
Week
I
80/0
281/0
68/0
172/0
IV
3J7/O
172/0
1
317/0
11
64/1
92/0
December
199,0
227.0
80; 0
265/0
90,0
199/0
476/01
January 19K6
IV
Note:
211/0
172/0
11
111
97/1
379/1
90/0
111
Week
463/7
317/0
172/0
201/0
InapartolPushpa Viiur. the bead* * ere constantlybeing removed as lhe ico Iienls were in lhe habit of drav. mg water
directly from the overhead tanks In view of this the entire Pushpa Vib ar area v. a»•. ta ken as control alt hough the area »a>
treated in the beginning
1
Indian Journal of Malanology
Vol. 22, December 1985, pp. 107-109.
/*
Field Trials on the Application of Expanded Polystyrene
(EPS) Beads in Mosquito Control
R.C. SHARMA . R.S. YADAV and VP. SHARMA-
In laboratory experiments expanded polystyrene
(EPS) beads were found very effective in the
control of mosquito breeding and they prevented
gravid females from laying eggs on the EPS
treated water surface (Reiter. 1978; Sharma.
1984). This is a report of the results of
preliminary field trials on the control ot
mosquito breeding in their natural habitats using
EPS beads.
I
L
I
Trials were carried out in Nadiad taluka villages,
district Kheda. Gujarat. The following sites were
selected: (i)a biogas plant, in the slurry around
the drum there was heavy breeding of Culex
quinquefasciatus
mosquitoes.
(ii) three
abandoned wells in which there was heavy
breeding of Culex sp. mosquitoes, and (iii)two
septic tanks in w hich there was heavy breeding of
Culex mosquitoes. Before the start of the
experiment, anti-malaria staff of the Municipal
department treated the septic tanks with
larvicidal oil (MLO). All immature stages of
mosquitoes died. The EPS beads were applied 1
week after MLO treatment to study whether the
Accepted for publication: 17 September 1985.
'Malaria Research Centre (ICMR)
Field Station
Civil Hospital
Nadiad-387 001, India.
^Malaria Research Centre (ICMR)
22-Sham Nath Marg
Delhi-110 054, India.
(
septic tanks would become positive for mosquito
breeding in presence of EPS beads. No M LO was
applied to the slurry of biogas plant and the
wells.
EPS beads were weighed and applied manually
bv hand at the rate of 50gm 1000cm2 in the
biogas plant (5 to 6 layers of about 2.6 cm
thickness). 20 and 85gm 1000cm2 (i.e., 2 to 3
layers of 1.0 cm and 9 to 10 layers of 4.4 cm
thickness) in wells and 70gm 1000cm2 in septic
tanks (6 to 7 layers of 3.6 cm thickness). The
density of immatures was measured in the biogas
plant and septic tanks by a 9.5 cm diameter
dipper and in wells by a 25 cm diameter well net
by taking an average of 5 samples each time.
Observations on the density of immatures w'ere
made on day 0 followed by weekly intervals upto
six weeks.
Results in biogas plant and wells are given in
Table 1. Breeding in the slurry of biogas plant
and well-I declined gradually and reached zero
level in the 4th week in biogas plant and in 5th
week in well-1. Whereas in well-II and well-III.
larval density reached zero in the second and first
week respectively and remained at that level upto
the 6th week post-treatment period, it may be
noted that breeding, continued upto four and
five weeks post-treatment in slurry and in one of
the wells. This was unusual as the breeding
generally terminates in the first one or two
o
oo
1
I
Table I. Impact of EPS beads on the control of mosquito breeding
Observation
Interval
(one week)
Density of Immature*
Biogas plant
IV instar
Day 0
Week I
Week II
Week III
Week IV
Week V
Week VI
Z
14 4
31.0
25.2
5.6
0
0
0
Pupae
4.X
5.0
9.2
2.0
0
0
0
Well I
Larval
density
65.0
56.6
25.2
5.6
0
0
0
IV instar
Pupae
z
Well II
Larval
density
Very high density
Very high density
11.0
0
334.5
4.5
0
46
6.5
0
15.5
0
0
0
0
0
0
IV instar
2.5
5
0
0
0
0
0
Pupae .
0
0
0
0
0
0
0
Well III
Larval
density
IV instar
239.5
7.5
0
0
0
0
0
0
14
0
0
0
0
0
Pupae
0
0
0
0
0
0
0
2
Larval
density
31
0
0
0
0
0
0
Notes: I. Rate of application of EPS beads was f'
50gm; -----1000cm2 (i.e.. 5 to 6 layers of 2.6 cm thickness) in biogas plant, 85gm,/1000cm2 (i.e.. 9 to 10 layers of
4.4 cm thickness) in wcll-l and III, and 20gm lOOOcm2 (i.e., 2 to 3 layers of 1.0 cm thickness) in well-ll
2. larval density includes the density of I, II, III and IV instars.
c
>
>
73
o
r
<
o
r
N
O
m
n
m
2
oo
m
73
o
oc
SHARMA et al.: FIELD TRIALS OF EPS BEADS
weeks. The beads on slurry develop the tendency
to stick together and these were being disturbed
by children. As a result breeding persisted for a
long time, however, educating the children
helped in keeping the layer intact on the slurry
and consequently the breeding was terminated.
In the case of well-I, some floating objects and a
dead dog created a feu spots where mosquito
breeding persisted. In other wells there was no
such disturbance. In the two septic tanks treated
with EPS beads one week after the application of
MLO, no egg rafts were laid by the mosquitoes.
These septic tanks remained negative for
mosquito breeding and for egg rafts throughout
the six week period of observation.
r
r 1
I
1
n
L
L
L
1
Wells are the main source of mosquito
production in many parts of India. In Delhi rural
Culex
areas,
profuse
breeding
of
while
quinquefasciaius occurs in wells
and
occasionally
Anopheles culicifacies
also
encountered
breeding
in
are
A.stephensi
wells (Sharma, 1985; Rao, 1984). In other parts
of the country- such as in Salem and Hyderabad
A.stephensi breeds mainly in wells and maintains
malaria transmission throughout the year
(Seetharaman et al., 1975; Batra and Reuben,
1979). Since EPS beads are safe and one
application lasts for a very long time, application
of EPS beads in wells can greatly reduce mosquito
breeding in wells and, it is hoped, would also
reduce or eliminate disease transmission. Similar
application of EPS beads in septic tanks can
eliminate an important source of mosquito
breeding on a semi-permanent to permanent
basis. Recently the Government of India has
placed considerable importance on alternative
energy sources, and installation of biogas plants
is one of the major areas receiving emphasis by
the Department of Non-conventional Energy
Sources. However, biogas plants are becoming
another source of mosquito production in rural
areas because the slurry of these plants supports
109
heavy breeding of Culex quinquefasciaius which
are vectors of filariasis and the major nuisance
mosquito. The application of EPS beads on
slurry of the biog?.- plants would eliminate this
important source of mosquito production, thus
improving the environment and reducing disease
transmission. In a recent study, Curtis and
Minjas (1985) have shown that the application of
beads in soakage pits and pit latrines is an
effective method of mosquito control.
In view of the usefulness of EPS beads in the
control of mosquito breeding, more trials and
integration of beads in the non-insecticidal
methods of vecter control are envisaged in the
near future.
REFERENCES
1.
Batra. C.P. and R. Reuben (1979). Breeding of
Anopheles siephensi (Liston) in wells and cisterns in
Salem. Tamil Nadu. Indian J. Med. Res., 70(Suppl.):
114-122.
2.
Cunis, C.F. and J.Minjas (1985). Expanded
polystyrene for mosquito control. Parasitology
Today, 1(1): 36.
3.
Rao, T. Ramachandra (1984). The Anophelines of
India. Rev. cd. (Malaria Research Centre, ICMR,
Delhi).
4.
Reiter, P. (1978). Expanded polystyrene balls: an idea
for mosquito control. Ann. Trop. Med. Parasitol., 72:
595-596.
5.
Sharma, V.P. (1984). Laboratory experiments on the
effectiveness of expanded polystyrene (EPS) beads in
mosquito control. Indian J. Malarial.. 21(2): 115-118.
6.
Sharma, V.P. (1985). Field experiments with thiotepa
sterilized Cule.x quinquejasciams in India. In
Integrated Mosquito Control Methodologies, v. 2
edited by M. Lrird and J.W. Miles. (Academic Press.
Neu York): 117-140
7.
Seetharaman,N.L.,M.L.Karimi andG.VenkataReddy
(1975). Observations on the use of Gambusiaaffinis
holbrooki to control A. siephensi breeding in wells.
Results of two years’study in Greater Hyderabad cityIndia. Indian J. Med. Res., 63: 1509-1516.
GUIDELINES EOR .PREVENTION OP HA LnE. 1A AL'D
JAPANESE ENCEPHALITIS IN ~REVERY ' VALLEY PROJECTS 4
^mpact of engineering, agronomy and water management practices on
disease vectors, transmitting Malaria & Japanese Encephali ti~~Tn^.India
Irrigated areas in India are increasing ivith the increased
demand for agricultural production.
for example rice fields
increased
from 29.8 million hectare in 1951-52 to 41 million hectare in
1983-84 of
vhich about 17.2 millions hectare arc irrigated.
Or
Lite
Lot. J 1
111iga ted
areas about 39 percent is irrigated by canals, 8.8 percent by tanks,
percent by tubewells,
20.7
24.9
percent by other wells and 6.5 percent by other
sovrces.
In India among the vector borne diseases, Malaria and Japanese
Encephalitis are of prime importance associated with irrigation
resulting from development of River Valley Projects,
potential
Lifierature is replete
with reports of increased incidence of malaria with the introduction
of
irrigation system.
Malaria endemicity and increased incidence of malaria
ceaths in Pattukottai regions near- Madras and Handya District in Karnataka
due to introduction of Cauvery - Mettur irrigation project in .'934 and
Vi svesvarya
canal respectively are well knohn.
incidence of malaria associated with
In the recent times high
Upper Krishiia River Valleu Project in
Karnataka has raised a controversy at International level
regard ing funding
of the project by World Bank.
Japanese Encephalitis is another important vector borne disease
which has become endemic in areas of intense rice cultivation.
between 1978 and 1987, 39,149 cases with 14,246 deaths a
ra ce of 36 per cent was recorded.
In India,
fatalitu
Economic losses as a result of high morbidity and mortality
ha ve
crippling effect on the economy of tbe country, besides individual
siff erings.
Therefore, introduction of river valley projects, wi thout
adeguate safeguards against these
harbinger of disaster
A
vector borne disease could become a
rather than ushering in an era of prosperity.
--------------------- -------
Prepared by Directorate1, of National Malaria Eradication Prccia-.o,
22, Sham Nath Marg, Delhi -110054.
2
BUDGET FOR I IEA L TH S EC '1VR:
It has been observed that practically all projects whether in
I
public or private sector earmark some
percentage of the estimated cost of
the project to meet the requirements of health
sector but all these
financial commitments are utilised towards CWVXTIVE aspects of the medicare
and not on PREVENTIVE
and recurring
aspect while much of the problems are preventible
cost avoidable, besides saving of productive man hours loss/
suffering.
PLANNING FOR PREVENTIVE MEASURES:
It is therefore, imperative that a carefully planned survey to
determine the adverse health impacts shouia
go hand
hand in
m hand
with engineering
should go
hand with
The findings of such a survey
surveys.
should receive full consideration
before finalizing each project which includes
not only the impoundment area
but also the distribution system and necessary provision
should be made
for implementing the recommendations in the estimate of the projects.
I
HEALTH SURVEY TEAM:
Health survey teams should comprise of public health experts viz.
Malariologist, Medical Entomologist, Public
Agricultural Engineers. Services of these
Health Engineers
and
r
I
experts can be provided/loaned by
Public Health/Agricultural Institution of the State and Central Government.
ENGINEERING MEASURES FOR PREVENTION OF MALARIA AND JAPANESE ENCEPHALITIS:
[
Engineering measures for prevention of malaria and Japanese
encephalitis should be incorporated as built in process of the project
and as such should receive consideration under the following three stages.
i)
[
I
Planning-and Design stage
ii) ' Construction stage and
ill) Maintaince stage
A.
PLANNING AND DESIGN STAGE:
a)
Selection of impoundment area
The final selection of impoundment areas which involves a
considerable amount of initial engineering surveys work should
Com,]
r
invariably be followed by malaria survey.
I.
Such surveys may also
include an investigation as to whether a provision could be
in
corporated for malaria surcharge in the dam/barrage height.
The
need for an induced periodic water level fluctuation in constant
level pools, appurtenant to the main impoundments
(i.e. barrage
ponds, and stilling basins) may not be a flat requirement, buz
rather a possible need to be considered in the
overall water
management plan so as to avoid loss of water i:.
function.
L
b)
!
The Dam Site:
Depending upon the topography of the country,
arise as a result of impoundment:
ged
two main problems
trees and vecetaticn to be submer-
and villages in the submersion area.
i)
Trees and Vegetation:
The area to be submerged may be inhabited and clothed wizh
forest or scrub jungle or be barren
with no mentionable vecezation.
Clearing the forest and scrub jungle preliminary to impoundage
5
is necessary and/or desirable from the point of view of the following:a)
Reduction of mosquito breeding potential
b)
Safety
c)
Safety of navigation, fish culture, fishing and other
i
of the dam and its appurtenances,
recreational vocations (boating etc.)
i' ■
d)
Avoiding the development of foul smell due to rotting
vegetation and discolouration of water.
H) Si ting of villages in
the submersion Areas:
Adequate arrangements will have to be made to ensure that the
villages in the submersion area are shifted well before actual
impoundage
begins.
It is here,
that a survey furnishing information
in regard to malaria hazards in the proposed rehabilitation area.
will be very necessary.
Preparation and ma in tcnancc of the shore
line and zone of fluctuation will have to be provided for
impoundments and barrage ponds.
It is desirable that the
both in
rehabili-
tated villages should not be within one and half KM of the highest
pool level of the reservoirs.
As health of the people in the
4
rehabilitation villages and those along the shore line
will be the direct responsibility of the project aul hoi Hies,
I
provision for protection against malaria will be most vital.
Hi)
Preparation of fluctuation Zone:
In every reservoir the zone of normal fluctuation will
require close attention.
Ordinarily, a reservoir fills during
rains (4 to 5 months) and a draw down period of 7 to 8 months
exposes several small collections of water and seepages in the
zone of (fluctuation where the two important vectors of malaria in
India,
viz., A.culicifacies and A.fluviatilis may breed luxuriantly.
These collections of water will have to be eliminated along the
periphery of the reservoir in the zone of fluctuation,
!
Close
vigilance will be necessary to watch all such pockets which may
breed mosquitoes.
Preparation of the zone of fluctuation should be
effected once during pre—impoundment and once again immediately
Qfter the first drawdown when these collections and seepages will be
more apparent.
iv)
i
i
Yearly review will also be necessary.
Seepage potential of Earthern Dam:
Earthern irrigation dams/embankments are prone to seepage and
r
I
its trapping becomes essential for safety of the dam.
p
However its
disposal never attracts the attention of the irrigation engineers
!
and this water is let loose and
results in ertfation of marshes and
swamps and thus become breeding grounds
of vector mosquitos and
the villages in the command areas show high incidence of
Hence,
malaria,
appropriate drainage schemes should be always developed and
incorporated as a part of the project to prevent malaria.
v)
Designing of Discharge gate:
Ihis requires attention at two points; exit gate and further
down stream.
a)
Exit gate:
The pitched/concerete areas against the discharge gate and the
speed breaker should be sufficient in number so that it should arrest
the speed of the water and should not create pond immediately after
the pitched area by
Erosion down .s tree•
I
5
b)
Down Stream:
I
The discharge of seepage water for Dam in non-irrigation season/
dry season often results in formation of pools in the river belt
which prolificly breeds A. culicifacies.therefore, it becomes necessary
to make provision for
flushing flows to combat this problem.
At dam site, where the bed is rockey a "cunette" can be
'build to stream line the flow of water' and prevent stagnat 2on.
vi)
Canal systems:
Untidy irrigation system is known to
set iii extensive
water logging of the areas which not only render the fertile loy,^l
into waste land, but also stagnates large bodies of water conducive
for breeding of A.culicifacies the vector of malaria.
laying
Therefore,
of canal system needs special attention and incorporation
of engineering design so that the irrigation becomes tidy.
The
following points need special attention.
1.
Alignment of canal/distributaries should provide adequate
drainage cuts to permit natural drainage of the area and to prevent
r
water logging.
2.
The canal system should provide very tidy irrigation by providing
infrastructure which would not lend itself to leakages.
technology of lining the canal system
sheet may be considered to
Modern
with low density polythene
prevent not only the water loss but
also the seepage of water.
3.
The canal should be designed straigt as far as possible
avoiding acute curves and with proper gradation for ensuring proper
water velocities.
4.
The burrow-pits for the construction of canal embankments should
be avoided as far as possible and may be relied on modern gadgets
to bring earthwork from elevated lands.
Should it become necessary
to dig burrow-pits they should be properly drained into natural
drainage system.
6
I
i
5.
Al icjnmcnt of the canal Jn arc.is w.i th high potential for
I
water logging should be avoided.
i
6.
Already water logged areas should be drained.
7.
Wherever a new canal is being dug to replace the old
/
canal system (as in the case of Upper Ganga canal project) the
iI
old canal system should properly be dressed so that docs not
retain rain water and provide linear breeding places for
mosguito.
vii) Drainage system of excessive water:
Whereas there exist provision for net work of irrigation
canal to take water to the fields for irrigation there does not
exist
r
I
any provision to drain the excess water from the fields or
seepage water being impounded in the adjoining low lying areas
along with fields.
Therefore, there is a need to
provide an
adequate drainage system for draining of the excessive water.
B.
f
CONSTRUCTION STAGE:
This stage has three phases:
f
- Construction of the dam.
- reservoir preparations, and
- excavation of the distribution system.
1)
Dam construction:
I
!
a)
Elevated and well drained sites should be selected for
location of several temporary labour camps and
permanent
colonies for the maintainence establishment.
b)
Jungle clearing around the labour camps should be undertaken
to expose the seepages/water collection for treatment of
larvicides.
c)
Antimalaria drains should be constructed for drainage of the
dam site.
d)
An organisation for carrying out recurrent measures for
any malaria hazard in different camps both for superior staff
and labour must be provided.
I
I
I
7
c)
/
There should be a close liaison between the engineering
department and the malaria organisations.
2)
Reservoir Preparation:
i)
Arrangement should be made for exploitation of
valuable timber.
ii)
Removal of all trees, bushes and other
getation likely
to emerge at maximum dra^' dov.n level of the reservoir.
It
is desirable that all trees within the submcrsive areas and
about 5 feet or more depending upon local conditions, land
word from the highest pool level should he cu~
uprooted.
but never
The trees should be cut as close as possible to the
ground level allowing stumps of not more than six inches.
;<L
iii)
Hi) Straighting
of margins through cutting,
deepenina
and filling of reservoir cdqe.
iv)
Filling of natural or man made depression in the vicinity
of reservoir or draining of these depressions by ditches
leading to the reservoir.
v)
.Provision of paths and other means of access to the
reservoir edge for vegetation clearance and fcr pesticide
application if need be*
vi)
■All protective works provided for the prevention of seepages
should be executed and it should be made obligatory that the
layout of borrow-pits be made a planned basis to permit
efficient drainage during the post construction operations.
C.
MAINTENANCE STAGE:
If all the requirements indicated by a previous detailed
survey of the area are incorporated in the project estimates and the
works are actually executed,
it is expected that there will be
little or no malaria immediately following the char.ne 1 sustem beinc
put into service.
Malaria that could be attributable to the
project cannot be kept down unless ail adequate provision
regular maintenance is provided.
for a
Where necessary for taking care
of any residual-malaria, recurrent measures
should be the
responsibility of the Malaria Ciganisat ion
of the project
/
the State concerned.
Specification lor Civil Woiks:
Specific^ ion for oxcoutin,/ of civii works connected with
River Valley Project are included in "Health Dull. No.32- "Malaria
Incident!al to Engineering Const met ions" PMEP 22-Sham Nath Ifirg,
Delhi-110054.
proccdnic for carrying survey works:
The procedure adopted by the earstwhile Mysore State now
Karnataka is cited below as an examplc :
River valley projects arc prepared by the Public horks Depart
division attached to the Chief
men t, major ones by the project
by project sub-divisions attached to
Engineer and minor schemes
the Circle Superintending Engineers.
Simultaneously with the
a development
according of administrative sanction to a project
of
committee consisting of the Chief Engineer and all the heads
i
constituted by the Government for all
developments as member is also
major projects.
Working sub-committees are also constituted to
The number of these
carry out detailed surveys, coordination etc.
main committee and their
sub-committee are considered by the
recommendations are forwarded to the different departmental heads
them,
who are responsible for implementing
sanction.
are debited to the
The cost of all engineering works
capital cost of the project.
are
after getting competent
One oi
mor e of such sub-commit t(
responsible for carrying out health surveys mainly with a view to
suggest measures for prevention of malaria developing as a
health problem.
Such a
committee consists of representatives of the
Health, Engineering, Irrigation and Revenue Departments.
They
r
L
included in the project list and put up detailed
jointly visit the area
proposals regarding:
1.
allgnment of minor channels:
within the flight
protective works necessary for any villages
range of local vector species;
works necessary within such a
ill. drainage and other protective
rams? as. in
(ii) above;
I
9
I
i v.
I
t.icatincj)t for tanks or other col]oct ions of water;
v.
crop planning, wit]) suggestions for t/n? types of crops
I (
to be grown; and
vi.
other rural amenities required, like drinking water wells.
schools, culverts, crossings across channels etc.
The above indicated procedure had been approved bu Cox'ornmen t
and sue]) detailed surveys have Jr.cn.cariicd out in respect of the following
projects:-
r
1.
Visweryariah canal arc, i,
2.
Narcuhalli project
3.
Tung a project
4.
Nugu project, and
5.
Lakkavalli project
/1/.77 Z'-l/.l'i/.l ' ‘ZrZlA’/:-U7H.7
Trd imi.narij ntaqr i TI ann i no and T'sian)
1
•)
Ma iai': d nd:■ f
3
4
Malaria Engineer
7 . ■> ‘hn i<» ianr
8
Insert t'ol l.rrt oy's
Mi 'di
:/
] 'n t ()mi > i (■<; i s f
('.'tains (\i an Km,>n;
!
/
r,> i ".a i
• )• f
■«<,
(
7, .
(
)
)
- •;
(ii(>(i 1 pf'rsonnd. may be supplied nr trniibd at the National Malari
1(7
Lradicataon E'rogramme, 22-Eham Nath Marg, Id hi\
Ccm n ti'ua t inn ;’>L(t(jc (Ave. cni on
1
4
.5
6
7
8
i t11 J .1 ■/ /<■ 1
Malaria Offid'rr
- i
Malaria taiginrrr - Trdinical J.ii’:'
M( ‘di<ni i En t.omc> / eg is t
-/
Malaria Inspector
-1
Superior Field Workers
- 8.
Field Markers
- 10
Lab. Technicians
-1
Jnsect Collector
-1
•) ■
( /'fny'. n/ )
1nsoo11 rides
l.arv id des
Equipment
Maintenance Stage
Camp and
Eeservoir
I.
II.
(a)
(Establishment vidr ronst rurtion staqc
(to be continued with suitable modification.
4 Area under irrigation
Staff
Malaria Officer (Entomologist) - I
Malaria Inspectors
-8
Superior Field Markers
-4 (
Field Markers
- 12( l.'A months
Superior Field Markers
- 20 (
Field Markers
- 1.10( 5 months
(b)
Malaria Engineer
with necessary subordinate staff for maintenance of
anti-malaria engineering works.
(e)
Con tifigencies
Transport
Motor boats
3 his establishmen t zs what is required J or i'rot <'(* 11
one million people,
suitable adjustment is, to bo made wnei'f' there is alrf'aau an oxisting
organisation e.g.f National Malaria Control units working in the different State:
V.’Ht >/Vr.C/8S . ‘h.o
APPENDIX 1
TECHNIQUE OF SURFACE OR OPEN DRAINAGE
Mosqui to> control ditches should be designed to drain an area in three to four days,
and pupae have had time to develop into adult mosquitos.
before larvae
1
Drainage lines should be as straight as possible to prevent erosion and to shorten
the length of ditches.
As a general rule, open drains should be narrow and deep rather than broad and
shallow.
The required depth of the drainage channel is usually determined by the level of the
outlet and, to a lesser extent, by the slope of -the land.
The nature of the soil also affect?, the depth and number of drains needed to keep
the groundwa ter level at a safe d i s Lane e I i om I I ie sui i .ice . Wlie re the ground
consists of clay, deepening a drain may not increase the area of its influence to
any measurable extent, because the friction exercised by the fine soil particles in
clay and their powerful capillary action may prevent the water from ever reaching
the drainage zone.
In such soils a large number of shallow drains may be needed
first, until the character of the soil improves.
Fewer drainage channels will be
required later, and the functionless drains can then be filled in and the remaining
drains deepened with good effect.
It is desirable to give a fall of at least 75 cm to the kilometre (1 in 1300), but a
fall of 20 cm to the kilometre (1 in 5000) may be sufficient if the ground is so
flat as to prevent a steeper g r a d i e n t.
The velocity of water should be kept below a safe limit in order to reduce the
Tins limit ranges from 30 cm per second in
erosive power or the cutting capacity,
fine sand to 90 cm per second in stiff clay.
The banks should be kept clear of vegetation and sloped to an angle of about
For example, an open drain averaging 30 cm in width at
45 degrees (i.e. 1 in 1).
In the coarser
the bottom and 120 cm in depth, should be about 3 m wide at the cop.
textured soils a 2 to 1 slope may be advisable, and very sandy soils may require
slopes of 3 to 1.
i
L
The bottom of narrow drains should be rounded and not flat or V shaped, but in broad
drains a shallow V is preferable to a flat bottom.
The drain is usually lined with concrete, brick, scone, etc., or may be simply an
earth drain.
It is not always necessary to line the entire depth of the drain, the
lining of the bottom and sides up to 10 cm above the normal water line being
sufficient.
For this purpose a pre-cast concrete invert can be used.
The spoil banks of a ditch should be moved back from the cdgic so as to leave a
"berm" about as wide as the ditch i.s deep, so that rainfall will not cause washing
of the spoil back into the ditch nor the weight of the spoil cause caving of the
supporting bank. Alternatively, the spoil may be spread over a wider area to reduce
its height and the corresponding pressure oni the supporting ditch bank;
in this
case, the wider spoil bank should be graded .so that rain which may fall upon it will
^run off away from rather than toward the excavation.
Smoothing the cop of the soil
bank while the recently excavated earth is scill soft involves only a little extra
labour, and may greatly facilitate any subsequent inspection or spraying of the
ditch since the* inspectors or spravmen can walk easily and quicklv down the spoil
bank instead of .stumbling along, a roug,h, overgjown uni ini:.bed h.ijik.
i
WHO/VBC/86.96O
page 66
I
ApprndJx 1
The excavation for drainage should start at the o.utfall end.
The main drain should be- constructed first, and the tributary afterwards.
Tributaries should enter at an acute angle or curve where possible, and not at right
angles, in order :<• lessen the deposition of silt and debris at the point of the
j unc t i on.
At the point of j notion with a side channel, the opposite side of the drain should
raised m prevent overflow.
be strengthened :
In places whordrain has to pass beneath a road by means of a culvert, the grade
of the drain si.on.d be increased to prevent the accumulation of silt or debris,
The
bottom, of the cui • ■ : t should be lined with stone or concrete.
In the case of lu.n.ill seepages, the best method is to construct a system of
contour drains, at right angles to the direction of flow, to intercept the seepage
above at the point at which it arises (intercepting drains).
The necessity for repeated cleaning of open earth drains makes their upkeep costly.
Lined drains last longer and are more easily cleaned, but these too require frequent
inspection and their cost of maintenance is by no means negligible.
I
page 67
appendix 2
TECHNIQUE. OF SUBSOIL OR
S.b.oU a„.n.£. 1. j
underground drainage
with mosquito breeding, since by
'■
have no access to
method which requires very
in the long run the least
applied,
considerable technical knowledge^
M
i
form of drainage when intelilgenciy
expens ive
•
* -i of which are placed subsoil pipes
Jor drain is a ditch in the bottom
— stone) to provide» an underground
A subsoil or under-orain
occasions, brushwood, bamboos^or
in with earth
the ditch being then filled
f
(or even, on
which
the
water
may
run,
channel through
the continuity of the surface.
to maintain
demand the placing of drains at
. •
used where conditions
in the
Subsoil drains are naturally
"Rurally
tion saves in upkeep and supervision;
their application
small intervals s
iculture, their use prevents the loss of cultivable ground.
case of many forms or agri
as it is
than 10 cm internal diameter is not advised,
The use of subsoil pipes less
liable to become choked.
found that smaller pipes are
The standard length is 30 cm, but pipe:>
^eater length are manufactured in the
case of pipes of a diameter of more than 20 cm.
In general,
less than 1.2 m.
should, as a rule, be laid ati a depth of not
The pipes
should be the depth.
the steeper the slope the greater sevenly graded and should
of the trench on which the pipe is laid must be as close together as
The bottom
placed
traight as conditions permit. The pipes are
be as s
of small stones.
and are kept in good alignment by means
possible
The pipes When laid in the trench ought always to be c°V^eJ ^"^“b^t^elt^ring
or with long grass or any other material which will aid^P
r
^/ihrt^and^es ^t^e^pen joints between the pipes.
This work complete,
the pipes are then covered with earth.
of subsoil drains as their roots may grow
Trees should be removed from the vicinity
Into and choke the pipes. The usual distance required for such clearing extends to
12 m or more from the pipeline.
collars are found useful in making joints watertight when
Socketed drain pipes
the drains are
the junction is
be 1
pipes may
away.
few outlets as possible,
Every subsoil drainage scheme should be Plan"e^.W1^h
as a rule into streams or
constructed of either concrete or bricks, and discha g g
lakes or ditches at a higher level.
there is a danger of cracking or
Never cover subsoil pipes directly with stones as
breaking the pipes.
be laid
a bottom layer of cinders or crushed stones may
In very soft and wet soil,
for the subsoil pipes.
as a foundation
VHO/VBC/88.960
page 68
App^n<3ix 2
Pipes to be laid from downstream upwards, always guarding against blockage at the
upper end.
Subsoil lines are spaced from 10 to 30 m apart, closer in heavy than in light soil.
Subsoil lines should be as straight as possible and any change in direction should
be by means of long and easy curves.
Changes of gradient should, be avoided wherever possible, especially if the change is
fro:: a steep gradic:..
.d one, as a sudden flattening of the grade causes silt
deposition in the flat
tion.
cion. The remedy is to construct a silt chamber at that
point.
To lower subsoil water, a ,.i adient of at least 25 cm per 100 m is usually required.
In sandy soil, a gradient as steep as 1:100 for 10-cm pipe and, in clay soil, 1:1500
also for 10-cm pipe;
and proportionately less for large-size pipes is better.
Subsoil pipes should be a_ least 1.2 m deep, or better still up to 1.8 m deep.
In
clay soil 60 cm is better than 1.2 m and, if the normal water-table is near the
surface, a depth of 2 m is better.
VHO/VBC/88.960
page 69
APPENDIX 3
CONSTRUCTION OF AN AUTOMATIC SIPHON AT
BOTANICAL GARDEN, PENANG
- ", is practically
1.
Botanical Garden, located approximately 8 km from George To-’n,
wide ravine divides'the area, through which flows the main rocky
surrounded by hills. A i
The whole area is
hill stream together with its. smaller branches flowing from the north.
One of
•r'der antilarval control rr-»-cr rising permanent drainage and weekly larviciding.
eekly
larviciding,
was
th-: branch streams, approxir cly 300 m long, which was under
of
an
automatic
siphon.
selected for the construct: n
The description giver. h' f2 is non-technical as the construction of this siphon is
2.
It is intended only to give some
purely based on field exper
:e flnd observation.
ractical hints in the method of construction, stage by stage, until it is completed,
p:------ ----- --- This construction was actually the result of a combined effort by a health inspector,
masons and labourers, Through such effort and direct field participation in the
construction, a successfully working automatic siphon has been erected.
’» firstly because of constructional and
The decision to construct the siphon was made
3.
be
sufficient and the flow of water
The
gradient
has
to
L~
operational feasibilities,
Further, with stopping of the weekly larviciding, labour
continuous throughout the year,
Furthermore, such a construction can give practical
may be deployed to other areas,
training to many inexperienced masons.
From field observations, the velocity of water, the depth and width of the stream
should be noted. The upper part of the stream should also be inspected to determine the
best possible point where the dam may be erected. The point chosen would be at a
slightly higher level which should net only assist to create a strong flush but also to
cover a reasonable flushing distance. That part of the stream should be sufficiently
wide to accommodate the size of the reservoir with minimum excavation.
The bed of the
stream should be firm and without any crevices or holes which could form underground
4.
I
outlets.
From field studies, it was decided to construct a ZO-cm
25-cm sipnon
siphon wicn
with a 1.35-m ^igh
5.
retaining wall. The reservoir would be 8.7 x 4.2 x 1.5 m, with a capacity of 55 m .
The whole construction was carried out by antimalarial workers, comprising six labourers
and three masons.
The first stage of construction began soon after the whole site had been cleared,
6.
The cement
cement concrete base is first prepared for s iting the dam outlet pipe.
From this
concrete is then filled in to complete the required length of the basement.
baserrent, the retaining wall is built up upwards, stage by stage.
A
The erection of the siphon pipe is the most important part of the whole
Antilarval
The siphon tube comprises several pipes joined together.
construction.
are
lar.ed
sewer
pipes
which
subsoil pipes can be used, though not as good as
are provided with
Furthermore
,
sewer
pipes
comparatively more intact and airtight.
Only the best pipes should be
C(onnecting heads which facilitate installation work.
hard
ringing
sound
when
the pipes are gently knocked.
selected. This is indicated by a 1
»
25
cm
in
diameter,
which is considered
The sewer pipes used for this siphon are
water
.
the
size
of
the
reservoir
and
flow
o
r
appropriate for t..---- -- ------ --
Two bend pipes are
8.
The siphon tube is erected at the centre of t!.- retaining wall.
pace
is
excavated
at the base of the
first joined together to form the siphon outlet,
•.itioned,
at
a
level
with the bed of
retaining wall where the siphon outlet is properlx
cted and erected vertically and, at
the flushing drain.
From this outlet, pipes are c
Pure white cement is used to
the same time, the inlet siphon pipes are also en •
:re
connected, the working level and
join the pipes.
Before these outlet and inlet pi;
maximum height of the siphon tube has to be deteri
VHO/VBC/88.960
page 70
Appendix 3
’. The height of both the inlet
9.
The reservoir is then filled up to the maximum level,
level
at
which
the
flow starts to trickle down the
and outlet pipes is thcr. adjusted to a ’—
then
the
pipes
are fixed into position and
outlet pipe. When this level is obtained,
connected.
. used1, three different sizes of air tubes were installed.
In the r
particular siphon
10.
tubershould be positioned beside the siphon tube, extending about “
30T cm longer
The air i
to
a
few
centimetres
rising
across
the
retaining
wall
and
down
t
than the siphon outlet,
a few centimetres
.
l
:
r
tube
is
made
to
extend
abov
the inlet openi
into the siphon tube.
The
Before the air tube ir> installed, its correct level must have been determined.
11.
>
to
maximum
level.
Holding
the
connecting
tube,
the
reservoir is again fille up
a
horizontal part of the a - : tube is inclined upward and downward. During the process,
certain level should be obtained at which a hoarse sound is heard within the siphon
That level indicates the correct functional level. The process of determining
tube .
this level can be time-consuming.
Having fixed the level of the air tube and the connecting tube effectively sealed,
12.
,
’’
the reservoir
is again filled up and the working
of' the-J siphon is tested. Once it is in
working order, the^siphon outlet pipe, the extended dam outlet pipe and the air tube are
covered with concrete and levelled about 30 cm above the bed of the flushing drain.
dram. The
■ vertical part of the air tube rising across the retaining wall down the inlet siphon tube
is also covered with concrete. The stream-bed directly below and adjoining the siphon
inlet is deepened to about 30 cm.
While the installation of the siphon tube is being carried out, part of^the^labour
force should prepare the concrete wall oni both sides of the reservoir. The flushing
of about 4 m to give the flowr an added initial
drain should be straightened to a distance
<-----Boulders available
the—site can be-used to construct the walls.
force.
-------- —at —
13.
14.
i
The entire work should be completed within two to three months.
The flush from this siphon was reasonably strong, lasting about nine minutes and
15.
-- m.. This
was subjected to repeated
covering an effective distance of some 200
*--- distance
---larval checking and no breeding was detected in the intervening water.
16.
For more than three years after it was built, the siphon worked perfectly,
maintenance work done was repainting of walls and siphon tube.
The only
17.
A total of 16 siphons is still functioning in the State of Penang, Their combined
Considering
that these siphons have existed more
flushing distance is more than 3000 m.
<
than 5'j vears and are still functioning, they have, compared with the cost of
larvic . ding, saved large sums of money on the cost of their construction. Automatic
siphon - have played an important contributing role in the overall antilarval programme in
the St..te of Penang.
I
L
PUBLIC HEALTH
WORKSHOP FOR ENGINEERS, ARCHITECTS, TOWN PLANNERS AND MOSQUITOGENIC
ADMINISTRATION ON PREVENTIVE AND CORRECTIVE ASPECTS 0
PROJECTS/WORKS.
CONDITIONS CREATED AS INCIDENTAL TO ENGINEERING
/19
DATE :
VENUE :
PROFORMA ON THE PARTICIPANT'S OPINION
1.
Whether you found the course
useful
Yes
No
2
Which aspects of the course
in your opinion need more
Lectures
Video Film
Any other
Field work
demonstration
3.
Whether the duration of the
course was adequate, if not,
kindly suggest the required
duration
Yes
No
4.
5.
What other disciplines,
besides engineers should be
given this training (list in
order of priority)
6.
Would you be able to implement
or utilize the knowledge gained
in your day-to-day work
1
I
What level of officers would
you recommend for future
workshops of this kind
7.
Would you suggest a capsule
course for undergraduates and
diploma course for engineering
students
8.
Do you feel the need of a policy
decision (i) at higher level for
implementation of
engineering
methods in the control of mosquito
breeding or (ii) it could be done
without any such intervention or
direction from above
9.
Any other suggestion or remarks
(Please use reverse side)
Date :
/19
AE
SE
EE
1.
2.
3.
4.
5.
Yes
No
Yes
No
(i)
(ii)
Name :
Designation :
(X) in the box if you agree.
Note : Please mark cross
Position: 1295 (4 views)