IMPACT OF MANGLA I S M PROJECT ON

ENDEMICITY OF MALARIA

Dr. Syed Mohammad Mujtaba

Engr. Syed Iftikhar Ahmed

Organized by

WORLD HEALTH ORGANIZATION Regional Office

for the Eastern Mediterranean

ENDEMICITY '6F W R I A

2 * D r . Syed Mohamaad Mujtaba Engr. Syed I f t i k h a r Ahmed ***

Introduction Of a l l the water-related diseases malaria presents the most ser ious publ ic hea l th problem i n Pakistan. It takes a heavy 5011 of hea l th and productivity, Since it leaves the victims weak and anaemic, and thus lowers t h e i r po ten t i a l for earning. I n an epidemic form it a f f e c t s advereely the i n d u s t r i a l and agr i cu l tu ra l production of the country. Since sporadic malaria epidemic a f f ec t s as many as 15 mil l ion people, Pakistan

occupies a prominent posi t ion on the malaria map of t h e world. (Fig. 1)

2. About 22 species of Anopheles mosquitoes have been iden t i f i ed i n Pakistan, which are l i s t e d i n Table I. Out of these species, Anopheles cu l i c i f ac i e s i s t h e moat important, eince it acts a s a vector of malaria. Its p re fe ren t i a l breeding places are : f resh r a i n water poola , w e l l s , waste i r r i g a t i o n water, c a t t l e ponds, sub-soil water swamps, rice f i e l d s , seepage f i l l e d borrow p i t s , i r r i g a t i o n channels with grassy banks, and surface drains.

3. Pakistan joined i n 1960 the world-wide malaria eradicat ion compaign sponsored by the World Health Organization, With the collaborat ion of WHO experts , a 14 years plan f o r malaria eradicat ion was prepared, Because of- some inherent defectis

* The views expressed i n t h i s paper are 'those of the authors and do not necessar i ly r e f l e c t t h e views of the Govt. of Pakistan.

** Director, Directorate of Malaria Control, Health Division, Govt, of Pakistan.

*** Chief, Water Resources, Planning 5 Development Division, Govt. of Pakistan.

i n the .plan as w e l l as i n t h e ope ra t ion approach, Slide

P o s i t i v i t y R a t e (SPR) after touching the lowest level of 0.2 i n 1966 inc reased t o as high as 15 i n 1972. (Fig. 2) With some effort it was brought down t o t h e l e v e l of 4.0

ove r a per iod of Ir years . I t has been observed that t h e SPR h a s a d i r e c t r e l a t i o n w i t h water a v a i l a b i l i t y for an m a . To i l l u s t r a t e t h i s p o i n t a comparison of the SPR and water a v a i l a b i l i t y dur ing 1975 f o r var ious provinces i s i n d i c a t e d below :

Water a v a i l a b i l i t y Province at f armgate SPR -

m l l l o n A c r e Feet ) Punjab Sind NWFP 1.9

Baluchis tan 0.5

86.0

4. Fu r the r t o i l l u s t r a t e t h e p o i n t , four d i s t r i c t s having maximum SPR each i n t h e i r r i g a t e d and t h e r a i n f e d areas of t h e Punjab are compared below:

Name of district SPR (a) 1rr ip;ated

i) Sahiwal 27.34 ii) Lahore 20.98

iii) Gujranwala 19.91

i v ) Guj ra t 18.12 ( b ) Rainfed

i) Campbellpur 4.35 ii) Jhelum 2.95

iii Rawalpindi 2.33

It can be i n f e r r e d t h a t t h e inc idence of malar ia is a func t ion of water resource a v a i l a b i l i t y .

5. An attempt has been made t o i den t i fy t he impact of water resources development p ro jec t s , i n general, and the

Mahgla Dam p ro jec t , i n p a r t i c u l a r , on t he pa t t e rn of endemicity of malaria. Other na tu ra l re levant f ac to r s such as topography, hydrology and c l imat ic conditions which are conducive t o breeding of mosquitoes have a l so been considered.

Topography E Climate of Pakistan 6. Pakistan is s i t u a t e d i n the t r o p i c a l b e l t of malaria, as it l i e s between 2Q0 and 37(' North Lati tude and 610 and 76O E a s t Longitude. It encompasses nearly 200 mil l ion acres of t o t a l surface area, of which 99 pe r cent is land and one per cent is water. The topography of the country var ies from snow covered mountains t o sandy deserts . (Fig. 3)

The mean annual r a i n f a l l var ies from 48 t o 2 inch. (Fig. 9)

The da i ly mean temperature i n the p la ins var ies from 40°c t o ~ O C . I n general the topography and the climatic conditions of Pakistan a re i d e a l f o r breeding of mosquitoes.

Water Resources Development 7. There are th ree hydrological un i t s i n the country; namely, t he Indus Basin, t he Kharan closed Basin and Mekran coas ta l aasin. (Fig. 5 ) About 70 per cent of t h e gross area of t h e country f a l l s under t h e Indus Basin, and Kharan and Mekran Basin each cover about 1 5 per cent of t he t o t a l geographical area. The Indus Basin can be c l a s s i f i e d as ho t bed of malaria. The basin is t raversed by 5 l a rge perennial r i v e r s and numerous seasonal streams. Nearly 3b.5 mill ion acres i n the basin are being i r r i g a t e d by 48 canal systems. The i r r i g a t i o n system consis ts of 5 large

and - d i m dams, 20 small d w , 1 8 r i v e r diversion works, 39,000 miles of canal , 3,700 miles of surface d ra ins , 161,000 number of tubewells. ( F i g . 6 )

8. The water resources development besides increas ing the production of food and f i b r e , br ings about changes i n t h e environment, readjustment of populaticm, calamities such as

waterlogging and s a l i n i t y , changes in climate ( increase i n humidity), and epidemics of water borne diseases. The water resources development p ro jec t s /programmes are being planned, designed, implemented and operated without paying due a t t en t i on t o t h e i r harmful e f f ec t s .

9 . There i s an ample evidence t h a t the areas which had low incidence of malaria, became hyperendemic regions after the construct ion of water development proj e c t s . The following aspects , r e l a t ed t o t h e water development p ro jec t s , are responsible f o r crea t ing conducive environment t o the breeding of mosquitoes :

a) A r t i f i c i a l fakes and rese rvo i r s created through construct ion of dams, barrages, diversion works across the r i ve r s : The r i v e r s and streams normally flow at high veloci ty and carry s u b s t a n t i a l amount of silt. '

This does not allow t h e breeding of mosquitoes. However, when the flow i s r e s t r i c t e d cr obstructed,on t he upstream of t h e obst ruct ion the water l e v e l increases , ve loci ty of flow decreases, and water becomes f r e e of silt. Reduction i n veloci ty and silt create ideal conditions f o r mosquito breeding. Rise i n water l e v e l fills t h e depressions along the r i v e r and when the l e v e l drops, t h e water s t ays i n such depressions. Such small ponds and lakes are responsible f o r breeding vectors of various diseases. b) I r r i g a t i o n channels: Nearly 25 per cent of water dei ivered a t the head of earthen i r r i g a t i o n channel i s l o s t due t o seepage and evaporation. Though the canal banks are desipned t o take care of hydraulic gradient', y e t the water seeps t o the borrow p i t s excavated f o r maintaining canal embankment. (Fig. 7) Such p i t s

are required t o be ploughed i n , bu t , i n p rac t i ce they are l e f t unattended and become permanent breeding places. The mean veloci ty i n the i r r i g a t i o n channels i n Pakistan varies f r o m 2.5 t o 4.0 f t /Sec . The veloci ty near the banks is, of course, much less than the mean velocity.

It has been observed t h a t on the channels with t h i ck vegetat ion growth along t h e banks, mosquitoes breed along the water l i n e . c) Drains: On account of non-avai labi l i ty of s t e e p natural grad ien t , d ra ins i n Pakistan have f la t slopes. Moreover, t h e d ra ins car ry s i l t free water, with t h e result that they get gut ted w i t h acquat ic plants . The d ra ins create pe r f ec t environment f o r t h e reproduction of mosquitoes. d ) I r r i g a t i o n Practices: Beyond t h e o u t l e t o r turn-out, as much as 50 pe r cent water is est imated t o be l o s t on account of s p i l l a g e , seepage, and evaporation. A part of t h e s p i l l e d water f inds i t s way t o low depressions and s tagnates i n small pools and becomes temporary abode of mosquitoes. Further , t h e rice f i e l d s usual ly flooded

with water are ideal breeding grounds f o r mosquitoes. Furthermore, i n t he Pancho System of i r r i g a t i o n , warm s tanding water i n t h e r i c e f i e l d s is replaced by f r e sh cool water from canals by l e t t i n g t h e warm f i e l d water flow t o low ly ing areas. Under t h i s l a rge a r t i f i c i a l lakes a r e created and areas around these lakes are swampped with mosquitoes,

* 10. A study was conducted i n Muzaffargarh District i n 1969

with a view t o establishing r e l a t i onsh ip between malariogenic

p o t e n t i a l s and i r r i g a t i o n channels. The population r e s id ing adjacent t o and away from t h e Muzaf fargarh canal was screened t o f i n d ou t t h e l eve l of human rese rvo i r . Whjle performing microscopic examination of blood through mass blood survey, it was observed t h a t t h e SPR was two times h igher among t h e population residing within one mile b e l t on e i t h e r s i d e of t h e canal than t he population r e s id ing f a r t h e r away. It was

* by D r . Bashirul Haq, Assis tant Chief, Health Sect ion, Planning E Development Division, Govt . of Pakistan.

a l s o observed t h a t t he dens i ty of vector mosquitoes

(&. c u l i c i f a c i e s ) was a l s o very high i n t h e human h a b i t a t s near t o the &anal. The observations were based on co l l e c t i on

of mosquitoes by space spray of l i v i n g rooms and cattle sheds,

Endemicfty of Malaria around Elangla Dam Projec t

11. It has been shown t h a t water resources s t r u c t u r e c lose ly

relate t o t h e pa t t e rn of endemicity of malaria, The impact of Hangla Dan; on endemicity of malar ia i s highl ighted ,

as an example.

1 2 . Mangla Dam i s a multipurpose p ro j ec t on t h e r i v e r Jhelum south-east of Islamabad. The p ro j ec t commenced i n 1962 and was completed i n 1967 a t a cos t of US $ 320 mil l ion. The

dam 1s designed t o conserve and cont ro l t h e f lood waters of

r i v e r Jhelum with a view t o supplementing i r r i g a t i o n shortages,

and generat ing power. The m a i r i e a r t h - f i l l dam which is 380 f t .

hlgh and 10,300 f t . long, s t o r e s 5.34 MAF i n t h e r e s e rvo i r

which extends 40 miles and has a surface area of 100 sq. miles.

(Fig . 8) For more t e chn i ca l data ,please see Table 11, It is est imated t h a t t h e n a t i o n a l benef i t t o t he a g r i c u l t u r a l

economy during t he normal r i v e r flow amounts t o US $ 34.7

mi l l ion (on t h e b a s i s of US $ 6.5 pe r acre foo t of s t o r ed

water) and ne t benef i t from power production is US $ 22.6

mi l l ion (on t h e b a s i s of US $ 0.005 pe r K.W.Hr. ) The maximum

r e s e r v o i r level a t t a i ned each year during t h e f i l l i n g

period is ind ica ted below:

Year - Date - Max. Reservoir Level

1967-68 Sept. 1 4 , 6 7 1202.32

1968-69 1t 5 $68 1202.10

1969-70 II 5 , 6 9 1202.09

1970-71 " 23,70 1193.57

1971-72 " 17,71 1183.76

1972-73 19 9,72 1202: 1 9

1973-74 " 13,73 1202.02

1 9 74- 75 r1 2,74 1173.65

It may be seen t h a t t h e r e s e rvo i r is f i l l e d during the swnmer monsoons, when t h e vector densi ty b u i l t s up progressively.

13. Owing t o t h e cons t ruc t ion of Mangla Dam, near ly 65,100 acres of land and 32,900 houses have been submerged, and 81,000 people have been af fec ted . About 20,000 fami l i e s had t o be r e se t t l ed . Due t o non-avai labi l i ty of s t a t e land

around Mangla some of t h e fami l ies had t o be s e t t l e d i n far away d i s t r i c t s having d i f f e r e n t environments. I n various d i s t r i c t s nea r ly 8300 ac res have been a l l o t t e d t o t h e new s e t t l e r s .

14. A s is apparent from Fig. 8, a huge a r t i f i c i a l l ake has been crea ted by impounding t h e waters of r i v e r Jhelum and i t s t r i b u t a r i e s . The dam has been i n operat ion s i nce 1967, thereby allowing t he examination of malariogenic po t en t i a l s over a 1 2 year period. Though no research study on t h e malariogenic e f f e c t s of Nangla Dam, as such, has been c a r r i e d ou t , ye t t h e rout ine work c a r r i e d out by t h e Malaria Control P ro jec t i n t he a r ea adjacent t o Mangla Dam provides morbidity

data. From t h i s da ta a glimpse of t h e epidemiological t r end of malaria can be s tudied.

15. The number of s l i d e s co l l ec ted through ac t i ve and passive case de tec t ion i n Mirpur District alongwith t h e r e s u l t s of microscopic examination are given i n Table 111.

A graphica l p resen ta t ion of the da ta has been made i n Fig. It is apparent t h a t i n 1969 (two years a f t e r t h e completion of t h e P r o j e c t ) , the SPR was as low as 0.32, and it has been r i s i n g s ince then and i n 1975 it was as high a6 2.236. Undoubtedly, the t r end i s i n l i n e with t h e s i t u a t i o n i n t h e o the r p a r t s of t h e country. It may be argued t h a t t he r i s i n e t r end i s not a consequence of t h e dam i t s e l f . However, it has been shown t h a t t h e epedemiological t r end of malaria has a d i r e c t r e l a t i o n

with t h e Water Resources Projects . The s to r ed water of l a rge dams is u t i l i z e d a l l over t he country and wherever t h i s water goes, it does leave a t r i a l of malaria.

16. Z t is unfortunate t h a t , while planning and designing t h e Water Resources Projects, no a t t en t i on hae so far been paid t o t h e remarks of S i r Malcohn Watson, who s a i d t h a t "Engineering which leaves a trial of malaria behind it, i s bad engineering".

17. Conclusion - tU compared t o nature , t h e man has produced b e t t e r environments and i d e a l h a b i t a t s for t h e vector of diseases which spread i n an epidemic proportion, - There is an ample evidence t h a t t h e water hrne vector diseases have a d i r e c t re lat ion with the development of water resources projects/programmas, spec i a l l y , i n the countr ies t h e topography, hydmlogy and climate of which i s appropriate f o r t h e surv iva l of these vectors . - Ins tead of waging only chemical w a r against: the vectors , a deeper th inking is needed i n con t ro l l i ne t h e vec to rbo rne diseases by other methods viz. environmental, b io log ica l , managerial, and self help. - A coordinated e f f o r t of planners, designers , engineers, l e p i s la t o rs , administrators , epidentologists , entomologists and the pub l ic at large is needed for cont ro l l ing and preventing t h e vector-borne d i s~asc~~.

Table I LIST OF ANOPHELES IN PAKISTAN

(1) Anopheles barbipostris van &r wulp, 1884

(2) II b6cianensis J-6, 19 XI- (3) t i &e var Similensis(J2mes) 1911 ($1 11 habibi - Mu?X.gan and Puri 19 36

ales v m der wulp

Giles , Pattan,

J-,

Theobald

a r i s t o p h e ~ ~

camboihu Ttaeobald

Theoba3.d

Theabald

Kaizunri Listcn, GMssi

GMssi Giles Giles

N.B. Out of the abcnre mticmed 22 Amqheline species A. d c i f a d e s and Stepbnsi are the mf irned vector species wh=rea6 A. fluviatifis S - ictus and maculatus (Hilly species)qpe the ~uqie,d sped-tan.

Table I1 (a) PERTINENT DATA ON MhNGLA 9AM

A. Hydrolo~ical

Cat- Area

ban h u a l Flw of River Jhelum at t4mgl.a Maxixum l3xbabI.a Flood t%l?dmm Mccarded FlOod

B. Other - Resermir

cmst kvel

12870 Sq. miles

Catastrcphic Flocd Level 1228 SPII

Yudmrm Ccnservaticn Level 1202 SPD MLnimnn Pool level Gross storage

Kve St-

1040 SPD

5.35 MAF

4.75 MAE' Length of he& Wl miles

Popdaticn Affected 81,000

Total to be aaph?ed 73,000 aaxs

C. DAMS - 1. Main Dam

Maxinum &i@t 380 ft. (crest level 3234 SPD)

-t Length 11,000 ft. 41 ft.

5.7 mcu. yd.

78.0 m.cu.yd.

purpose Storage and Ebm -- crest wgm

234 ft.

5700 ft.

Top Width 41 ft.

Table I1 (b)

3. sukirm Qvke

MPcinwm Height

Crest h g t h Excavaticn

Fill

D. Spillways 1. Main Spillway

Type No. of e g s

Size of Gates

lLpe

Capacity Excavatia

(h-lCrT?te

2. FfilesErlency Spillway

Type Exoavaticn Conete

Crest Elevation

-tY E. Hydro-Electric Works

1. Tunnels No. of Tunnels Size Length

Tunnel Excavation Concrete

2. P a e r Statim (lst Stage)

Tu&o.Alternatw Sets

Capacity (each set)

Cancrete

3. P w e r Station Tailrace

Excavflcm

Clnregulated apen cut.

16.3 m.m.yd.

0.014 m.cu.yd.

1206 Sm> 212,000 mew.

5

30 f t . d iamete r (Finishe.' 2000 f t . each

0.319 n. cu. yd.

0.131 m. cu. yd.

-12-

Table I1 ( c )

4. Bcay:CBlal Capacitu m?tfi Bed Width

Excavaticn F. Total Principal Estimated

Quant i ty Excavation

40,000 mecs 37 ft.

100 Et. 15000 ft.

10.5 mcu.yd.

55.0 m.cu.yd.

108.3 m. cu. yd.

T a b l e I11

SURVEILLANCE DATA OF MIRPUR DISTRICT 1969-76

Slides Slide Examined P.v. P.f. Tot a1 Positivity pats