report on preliminary survey by who bilharziasis advisory

Bull. Org. mond. Sante 1 1962, 27, 5-24Bull. Wld Hitha Org.

Report on a Preliminary Survey by the WHOBilharziasis Advisory Team in Upper Volta

DONALD B. McMULLEN 1 & JEAN FRANCOTiTE 2

The WHO Bilharziasis Advisory Team made a survey in Upper Volta during May andJune 1960. Data available indicate that S. haematobium is widely scattered throughoutthe country and that about 50 % of the population, or more than 1.5 million people, areinfected at some time during their lives. The examination offaeces is not a common practice,and it is therefore impossible to estimate the prevalence of S. mansoni and the intestinalhelminths. The available evidence indicates, however, that S. mansoni is more prevalent inthe country than is generally suspected. The distribution of the known snail habitats andthe bilharziasis foci indicate that most of the major watersheds are infested, but that trans-mission sites may be rather sharply defined. It will be necessary to take this and variousseasonalfactors into consideration in planning a bilharziasis controlprogramme.

An analysis of the various public health problems in the country indicated that a pro-gramme of bilharziasis control would not be ofpractical value unless it was combined with ageneral attack on filth- and vector-borne diseases, and that it was essential to considersuch a programme in conneixon with plans for the development of water and soil resources.

INTRODUCTION

In 1958 the World Health Organization estab-lished the Bilharziasis Advisory Team, composed of aparasitologist-epidemiologist and a public healthengineer with experience with irrigation projects.This team was to operate on an interregional basisand would be available to make surveys in variouscountries at the request of the governments con-cerned. In response to such a request from theGovernment of the Republic of the Upper Volta, theteam made a survey in that country during a33-day period in May and June 1960. The materialobtained during this survey may be taken as anexample of the type of report that has been preparedon surveys in 14 other countries since the establish-ment of the team. The stated objectives of suchsurveys are as follows.

(a) To estimate the seriousness of the bilharziasisproblem in each country; to determine whetherthere have been changes in prevalence and morbidityrates, especially in relation to the development ofirrigation schemes; and to advise on the mostup-to-date control methods applicable to localconditions.

(b) To investigate methods for the prevention ofthe spread of bilharziasis in connexion with the

Team Leader, WHO Bilharziasis Advisory Team.2 Irrigation and Sanitary Engineering Consultant, WHO

Bilharziasis Advisory Team.

development of hydro-electric power systems andirrigation methods or other economic or engineeringschemes.

(c) To review community development pro-grammes in areas where the bilharziasis problemexists with a view to advising on measures for theprevention of bilharziasis.

(d) To appraise freshwater ecology data and tosuggest appropriate ecological control measures inthe planning of irrigation, drainage and watermanagement schemes; if no such data are available,to plan studies in this field.

(e) To make recommendations for the co-ordina-tion of activities of agencies responsible for theprevention of the spread of the disease and thoseinvolved in the development of water resources.

(f) To consider the economic implications ofengineering control methods proposed for theprevention of the spread and for the control ofbilharziasis.

(g) To advise on long-term plans for bilharziasiscontrol.

PREVALENCE, EPIDEMIOLOGY AND IMPORTANCEOF BILHARZIASIS

Prevalence of bilharziasis in Upper VoltaSchistosoma haematobium. In the West African

countries previously surveyed by the team, data on

1144 - 5-

6 D. B. MCMULLEN & J. FRANCOTIT

the prevalence and distribution of S. haematobiumwere almost non-existent or of relatively little valuefor pin-pointing important foci and for use inorganizing control programmes. In these countries agreat deal of the data available came from hospitals,dispensaries, and mobile survey teams. These unitsusually sort out the cases on the basis of complaintsand the prevalence rate for S. haematobium infectionis based on the total number of persons examined.The rates determined in this way are always quitelow. A good many of the data available in UpperVolta also were of this type. For example, 9103cases were reported in 1958 and 13 246 in 1959, outof more than 1.25 million persons examined per year.Other data available in Upper Volta show thatfigures of this type have little relationship to theactual prevalence.Most of the data acquired before 1950 in Upper

Volta were of little value in determining prevalence,but Deschiens (1951) reviewed the informationavailable and listed eight of the major towns in thecountry as foci and estimated that 46% of thepopulation were infected with S. haematobium.In a letter 1 sent out from the Ministry of Health tomedical officers the methods for conducting moreadequate surveys were well presented. This wasfollowed in Upper Volta by a series of urine surveysthat vary in quality in different parts of the country,but the data obtained are among the best availablefrom the countries south of the Sahara and the resultscan be used to obtain a rather clear picture of thegeneral distribution of S. haematobium. The mostextensive of these surveys were by Sansarricq &Marill 2 and Marill (1957). Since much of thismaterial is scattered through many reports andvirtually impossible to use in its present form, asummary of the data found has been given in aseries of tables and an attempt has been made tolocate important areas on the accompanying map.Differences in spelling, the lack of a complete set oflarge-scale maps, etc. made it impossible to locate allthe villages.

In Table 1 it will be noted that surveys amongchildren showed that in two villages (Dohoun andKoungoussi) all of them were infected. Five villagessurveyed did not have the infection, 21 had less than10% and 34 had more than 50% infection.Table 2 lists the various centres that have been

1 Instruction NO 3/51, Enque6te sur les bilharzioses en A. O.F.,7/6/51.

' Reported in an unpublished document (1957) entitledBilharziose ti Schistosoma haematobium, Haute Volta,Region Bobo-Dioulasso.

reported to have S. haematobium infection but wheredefinite data were lacking. The comments madeabove about the location of these villages on themap apply to this list.

Table 3 summarizes the data contained in Table 1,from villages where actual numbers of personsexamined, etc. were given. In this table it will benoted that the percentages given, where the sex of thechildren was recorded, indicate that the males had amuch higher rate than the females. However, themuch larger group where the sex of the children wasnot recorded, but which probably was predominantlymales, gives a somewhat different impression.

Table 4 gives a summary of the data obtained fromthose villages where predetermined ratios of adultmales, adult females and children were examined.In general, the infection appears to be slightly morecommon in adult females than in males, and theinfection is considerably less common in adults thanin children. These data indicate that if Deschiens'estimate of 46% is applied only to those actuallypassing eggs, it may be too high. However, if oneconsiders that (a) 30%-45% of the children haveactive infections, (b) some adults no longer pass eggsfrom an earlier infection, and (c) some adultsacquire the infection later in life and are passingeggs from this or an earlier infection or both, itmay be that about 50% of the population, or morethan 1.5 million people, do become infected at sometime during their lives.Nothing is known about the residual effects which

these infections have on the people. It was noted inthe annual reports, however, that chronic urogenitaldisturbances, such as cystitis, lithiasis and unspecifiedconditions, were very common. While this is ascribedto venereal disease in the reports, and it is statedthat many of these cases were drug-resistant, onewonders what proportion of these conditions mayhave been caused by chronic S. haematobiuminfections.

In a an unpublished report 3 on a malaria surveymade in the vicinity of Man, Republic of IvoryCoast, by a team from Centre Muraz, Bobo-Diou-lasso, it was noted that the splenic index amongchildren at Boue was considerably higher than theparasite index. Since this village was found to haveS. haematobium infection, it was suggested in thereport that this infection might be a factor. Aperusal of two different tables in the report gave thedata shown in Table 5.

' Rapport sur la Mission effective dans la Region de Man,Republique de la Cote d'Ivoire, du 21 mars au 8 avril 1960.

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TABLE 2SUMMARY OF OTHER CENTRES WHERE S. HAEMATOBIUMINFECTION IS KNOWN TO BE PRESENT BUT FROM WHICH

LESS DEFINITE DATA WERE AVAILABLE

Village | AdministrativeVillage ~~~~divisionNiyonbiniBatieBati6-NordLokossoBouss6raKpampkounaTomboliBoropoOuango-GiflniTehiniBamakoTourniKiribina-Karaflgu6laDounaYahoOuryDidyrImassagoKokologoNanoroPouniReoSigl6KindiPelaThyouS6g6n6gaKassoukaThiouNamissiguimaZogor6InganeBasciZigaGorum-GorumBaniMartioyiGaryodgiBarsaloghoTougouriBoulsaPinsaKorsimoroManeBogand4Diabo

GaouaGaouaGaouaGaouaGaouaGaouaGaouaGaouaGaouaGaouaDi6bougouOrodaraBanforaBanforaBoromoBoromoKoudougouKoudougouKoudougouKoudougouKoudougouKoudougouKoudougouKoudougouKoudougouKoudougouOuahigouyaOuahigouyaOuahigouyaOuahigouyaOuahigouyaOuahigouyaOuahigouyaOuahigouyaDoriDoriDoriDoriKayaKayaKayaKayaKayaFada N'GourmaFada N'GourmaFada N'Gourma

The data from the first five villages show that theparasite index is either higher than the splenicindex or the latter is only slightly higher. The datafrom the other seven villages show that the differ-ence between the splenic index and the parasiteindex ranges from 21 % to 51 %. From the presentauthors' survey in Ivory Coast, it is known that threeof the latter villages are S. haematobium foci, with25% to 66% of the children infected. Similar areasmay be found in Upper Volta and a study of theetiology of the enlarged spleens and possible implica-tions would be of interest.

Schistosoma mansoni. As a result of the selectivemethods used in the examination of patients, and therelative difficulty of making faecal examinations,there are no statistically valid data on the prevalenceof S. mansoni in Upper Volta. In his review Des-chiens (1951) reported the parasite at Ouagadougouand Bobo-Dioulasso and estimated that 8% of theUpper Volta population was infected. Scraps ofinformation in recent reports indicate that theparasite may be endemic in at least eight generalareas (Table 6), but all of the towns mentioned aresimply hospital centres to which severe cases gravi-tate. The few data available and the presence ofthe intermediate hosts for this parasite in the southernpart of the country (see following section) indicatethat this infection may be more common than isgenerally supposed. There is some meagre supportfor this idea in the various reports.At the Bobo-Dioulasso Hospital in 1959, 292

faecal examinations were made on patients withgastro-intestinal complaints. Of these, 99 (34%.)had S. mansoni and four of the eight patients hospita-lized were children under one year of age. Examina-tion of the more recent records revealed that duringthe first few months of 1960 the ratio of S. mansonicases found to those of S. haematobium was 47:137.Considering the relative unpopularity of stoolexamination and the ease with which symptoms ofS. haematobium infection can be elicited and thediagnosis made, this is a rather high ratio.

SUMMARY OF DATA IN TABLE ITABLE 3

FOR VILLAGES IN WHICH ACTUAL NUMBERS OF PERSONS WERE EXAMINED

Children

Females Mixed Total

Adults

Males Females Total Mixed

43/156 5 176/18 265 5 500/18 918- 213/925 241/925 453/1850 147/867 6 100/21 635

27% 28.3% 29.1 % 23% 26% 24.5% 17% 28.1 %

Mixedpopulation-I

12

SURVEY BY WHO BILHARZIASIS ADVISORY TEAM IN UPPER VOLTA

TABLE 4SUMMARY OF DATA FROM AREAS WHERE

PREDETERMINED RATIOS BETWEEN ADULT MALES,ADULT FEMALES, AND CHILDREN IN EACH VILLAGE

WERE EXAMINED a

Group Number Number PretgGroup examined positive Percentage

Children 1900 833 44

Adult males 925 213 23

Adult females 925 241 26

Total J 3750 1 287 34

a See Table 1.

Since the team's visit in Navrongo, Ghana, in1959, a survey has been made of the persons comingto the hospital there and it has been found thatabout 10% have S. mansoni. At Po, just a shortdistance across the border in Upper Volta, faecalexaminations have not been made and the parasitehas not been reported.The data avaiiable indicate that scattered trans-

mission sites may occur throughout the BlackVolta and Comoe watersheds in the southwesternpart of the country. The team's finding of Biom-

TABLE 5SUMMARY OF SELECTED DATA FROM A MALARIA

SURVEY MADE IN THE VICINITY OF MAN, IVORY COAST

Splenic index Parasite indexVillage No. inf./

%No. inf./ %

No. exam. A No. exam. A

Dain6 17/31 54.8 17/31 54.8

Zeregouin6 26/122 21.3 35/123 28.5

ZagouL 49/169 29.0 37/170 21.8

Kabakouma 29/57 50.9 28/57 49.1

Zouzousso 23/37 62.2 28/37 75.7

Trokpadrou 108/152 71.0 76/152 50.0

Siemien 82/116 70.7 44/117 37.6

B6ou6 41/59 69.5 24/59 40.7

Gbomello 31/49 63.3 6/50 12.0

Bagouin6 18/25 72.0 9/25 36.0

Gbanbegouin4 49/71 69.0 15/71 21.1

Lagoulal6 49/67 73.1 15/68 22.0

TABLE 6SUMMARY OF CENTRES FROM WHICH

S. MANSONI INFECTION HAS BEEN REPORTED

Village Report

Koudougou Some S. mansoni

Banfora Some S. mansoni

Fada N'Gourma 6 S. mansonl (1955)

Tenkodogo 7 S. mansoni (1957)

Bobo-Dioulasso 36 S. mansoni (1958)

Bobo-Dioulasso 35 S. mansoni (1959)

Nouma 4 S. mansoni (1959)

Ouahigouya 2 S. mansoni (1958)

Gaoua 3 S. mansoni (1958)

phalaria at Tenkodogo and reports of cases fromthat same area indicate that at least the lowerreaches of the White Volta may contain foci. Onthe other hand, in areas where the parasite might besuspected, it is of interest that surveys involvingseveral hundred stool examinations have shownTrichomonas, amoebic cysts and trophozoites,Taenia, etc., but no S. mansoni. There is no evidencethat the parasite is endemic in the northeastern partof the country. At present it is impossible to estimatehow many persons in Upper Volta are infected withS. mansoni.

Intermediate hostsAttempts were made by the team to find molluscs

in all the areas visited. While it was possible toobserve numerous potential habitats throughout thecountry, apparently it was not the ideal season forsnail surveys. In many cases the habitats had beencompletely dry for several months, in others onlystagnant pools unsuitable for snails remained, andin a few places the wet season was beginning and thehabitats had only recently received fresh water. Inthe first two types of habitat, usually only shells ofsnails were found, and the other places cannot beconsidered negative without further study. Many ofthe recently filled habitats were also negative or hadonly immature snails that could not have beenproducing cercariae. At present it appears that thegeneral lack of irrigation schemes and other waterresource developments tends to confine most of thetransmission of bilharziasis to natural bodies ofwater and ponds.

2

13


TABLE 7SUMMARY OF AREAS IN UPPER VOLTA REPORTED TO HAVE BULINUS

AND BIOMPHALARIA

Bulinus (Physopsis) Bulinus (B.) forskaiii Biomphalarla

From previous reports

Leo

Garongo

Tangar6

Barasgo

Guirgho

Bobo-Dioulasso,vicinity: 6

Tambili

Zitenga

Tieb6I1

Djiba

Toudou

B6r6

Kayao

Fada N'Gourma



From observations by WHO Bilharziasis Advisory Team

Liguidi-Malrama

P6

P.K. 55,a south ofOuagadougou

Koudougou,vicinity: 2

P.K. 5, south ofOuagadougou

Gaoua

Banfora, vicinity: 2

Sian

P.K. 4, south of Ouagadougou


Gouga


Nobili

P6

P.K. = Kilometric point.

These observations and a study of the data onrainfall (averages for 10-40-year periods up toDecember 1958) indicate that transmission in UpperVolta may be quite seasonal, except in a few placeswhere suitable habitats exist throughout the year.In some instances, it may even be possible thatconditions for the development of cercaria-producingpopulations of snails may occur only occasionally,during a period of several less dry years. A few of the

potential habitats seen had been dry for more than a

year and the presence of dry shells may have been noindication that they had recently been breedingsites. The only relatively dense living population ofmature snails which had reached the age of cercarialproduction was found in a permanent reservoir atthe edge of Po. This consisted of Bulinus (Physopsis)sp., and an examination of the collection showedthat 30% of them carried an infection with a mamma-

Guiaro

Bourra

Bousa

Lougogo

Soubega

Manga

Hound6

Santidougou

Sidenga

Agonon

Mousa

To6c6

Bind6

Nob6r6

Yalou

Koungoussi

Gaoua

Banfora

Bandassago

Goubr6

Penti4ri

Tenkodogo

Di6bougou

Tougan

Koudougou,vicinity: 2

Tenkodogo

14


TABLE 8SUMMARY OF POTENTIAL HABITATS EXAMINED

Type No. examined No. negative Bulinus (P.) Bulinus (B.) I Biomphalaria Other | Bivalves

Barrages, reservoirs,causeways, etc. 38 17 9 8 3 10 9

Lakes 6 1 1 1 0 1 0

Streams, pools, etc. 24 15 3 4 0 5 1

Bayous 4 3 1 0 0 0 0

Irrigation canals 2 a 2 0 0 0 0 0

Borrow pits 2 a 1 1 1 0 0 0

Fish ponds 2 a 2 0 0 0 0 0

Total 78 41 15 14 3 16 10

a Localities, rather than actual number of habitats examined.

lian type of schistosome, presumably S. haematobium.In the other areas, where the habitats were lesspermanent, it appeared that in the northeastern partof the country transmission would probably belimited to a period between August and November.In the southwestern part of the country the period oftransmission in such habitats may be somewhatlonger, possibly from June to November. It appearsthat these seasonal limitations may be used to saveeffort and expense when control programmes areplanned. However, it will be necessary to study theeffects of the seasonal and year-to-year variationsin rainfall on snail breeding, survival, infections andgeographical distributions before control measurescan be applied intelligently. Also it should beremembered that water resource developmentswhich increase the number of snail habitats orprolong the period of cercaria production, or both,will result in an increase in bilharziasis prevalenceand in the intensity of the infections.

Table 7 summarizes the information available onthe distribution of the two different types of inter-mediate host and Bulinus (B.) forskalii. Before theteam's visit Bulinus (P.) sp. had been reported from35 areas and 14 sites were added during the survey.While collection records for this snail indicate thathabitats are relatively numerous in the southern partof the country, scattered foci have been found in thenorth and prevalence data indicate that undiscoveredhabitats must be present. B. (B.) forskalii had beenreported previously in five habitats in the vicinityof Bobo-Dioulasso. The team found this snail in

ten additional sites. While the known habitats forthis species are widely scattered, they tend to be in thesouthwestern part of the country. Table 8 summa-rizes the types of habitat examined and what snailswere found. Under the circumstances and thelimitations of such a brief survey, it appears thatstreams and reservoirs are the most commonlyinfested habitats.

Biomphalaria had been reported previously infour sites in the vicinity of Bobo-Dioulasso. Theteam found this snail in two habitats in the vicinityof Koudougou and in one at Tenkodogo. It will benoted on the map that these sites are widely separated.and in different watersheds.During the surveys two species of bivalves were

found in ten widely scattered sites, Lanistes in seven,Lymnaea in three, and Gyraulus in three. The lastspecies was the only mollusc found (shells only) inthe dried habitats in the vicinity of Dori, in thenortheastern part of the country. One gets theimpression that the life of molluscs in Upper Voltais often a difficult one.

Relationship of bilharziasis to other diseases

F: While greater emphasis seems to have been placedon the other diseases in Upper Volta, especiallythose considered to be among the grandes endemies,malaria appears to be the most common and mostimportant single disease in the country. Thisimpression was gained from medical officers in thefield and from the review of various reports. For

15

16 D. B. MCMULLEN & J. FRANCOTTE

example, in 1959 there were 226 838 cases of malariareported from all the medical units in the country,out of 1 277 090 persons examined. While a greatmany of these cases were reported by dispensaries onthe basis of clinical symptoms alone, some specificdata lead one to conclude that malaria prevalence ismuch greater than these figures indicate.

In a survey 1 made by the Service des GrandesEndemies in the vicinity of the Sourou River in 1954,among 4906 persons examined under 20 years ofage, the splenic index was 72.45% and the parasiticindex 86.7%. Among 942 persons over 20 years ofage, the same indices were 2.95% and 75.5 %respectively. Nearly 99% of these infections werePlasmodium falciparum and the remainder were P.malariae. In many of the villages surveyed thechildren in the age-groups 0-5, 6-11 and 12-23months were all infected. In the examination of299 schoolchildren in Gaoua, 39% were found tohave positive blood smears. In the school at Massala,52% of 105 pupils had splenomagaly and 10% hadpositive blood smears. In the annual report of theHealth Service for 1952 it was said that 24% of12 827 schoolchildren examined had enlargedspleens. In all but one area visited by the team,malaria was considered the greatest single cause ofmorbidity. It was impossible to reach any conclu-sions concerning mortality rates, but they must inall probability be high.

Meningitis and measles occur in epidemics inUpper Volta and are greatly feared because of theirdramatic course and the high mortality they cause.In several areas it was stated that these two infectionsand malaria produced a 50% mortality among chil-dren in the 0-2-year age-group.

Leprosy is still a serious problem in the countryand one source indicated that there may be 100 000cases. The number of cases of trypanosomiasishas been greatly reduced but the residual for theinitiation ofepidemics remains. Trachoma is a majorpublic health and economic problem. In 1959 atotal of 33 527 cases of dysentery were reported.While 6877 of these were said to be of amoebicdysentery, one cannot be certain how many wereconfirmed by microscopic examination. It is known-that a great many of the other dysentery cases werediagnosed in the dispensaries on a purely clinicalbasis.While it is generally agreed that the intestinal

helminths are practically universal, it is impossible

,LReported in an unpublished document entitled Valledu Sourou. Rapport entomo-,pidemiologique.

to get substantiating data on prevalence. In con-nexion with a trypanosomiasis survey made by ateam from Centre Muraz, stool examinations weremade on 114 persons, mostly children, in Diemanso,Kassoba, Souma and Dinderesso. Of these, 20%had hookworm and it was simply stated that severalwere infected with Taenia and Ascaris. The annualreport of the Health Service for 1949 gives theresults obtained from the faecal examination of60 Europeans and 2763 Africans with dysentery.The percentages have been calculated and summa-rized in Table 9.

In nearly all hospital reports hookworm is givenseparately and other intestinal helminths appear ina category headed " intestinal worms ". In thereports from the dispensaries and mobile teams boththese types of parasite appear under the latterheading. In 1959 a total of 2724 hookworm caseswas reported and from both sources there were25 579 cases of " intestinal worms ". Considerableimportance was attached to the prevalence of hook-worm and its association with anaemia in reportsand in discussions with medical officers, but signi-ficant data were not found. It did appear, however,that hookworm infections were more common inthe southwest and less so in the drier northeast partof the country.Of 299 blood smears examined at Gaoua, 11%

had microfilariae. In the vicinity of Bobo-Dioulasso

TABLE 9

SUMMARY OF PREVALENCE RATES OF INTESTINALPARASITES AMONG PATIENTS WITH DYSENTERY

Percentage positiveParasite

Europeans Africans

Endamoeba histolytica 38 70

Eschirichia coli 62 61

Giardia 37 16

Balantidium 0 0.5

Trichomonas 0 5

Hookworm 0 20

Ascaris 5 2

Strongyloides 1 1

Trichuris 25 0.4

Enterobius 0 0.6

Taenia 5 12


some elephantiasis has been reported, but data fromone survey indicated that Dirofilaria perstans wasmuch more common than Wuchereria bancrofti.In nearly all of the centres visited foci were mentionedwhere dracunculosis and onchocerciasis were seriousproblems. About 6000 to 10 000 cases of the formerinfection have been reported annually since 1951.It was stated that large tracts of fertile land hadbeen abandoned as a result of onchocerciasis in thesouthern parts of the Red and White Volta Riverwatersheds. This usually occurs when about 30%of the people in a village are blinded by the infection.These areas are relatively obvious on the maps of thecountry which show population distribution. Asfar as records indicate, however, blindness andmigrations from infested areas have caused thisdisease to assume importance out of proportion tothe actual number of cases.Data were scarce on parasitic infections in do-

mestic animals. In one instance it was stated thatabout 40% of the calves die of parasitic infections.In 1959, 1200 livers of inspected cattle were con-demned because of Fasciola gigantica. In Touganthe veterinary officer reported that 30% of 61 1 cattleinspected in 1959 had fascioliasis. However, theparasite is not considered a serious problem in thecountry. Cysticercosis, enchinococcosis, and sarco-sporidiosis are common. Reports on the presenceof Schistosoma bovis varied in each area visited.Trypanosomiasis and anthrax were said to be themost serious problems. From the records and inter-views there is some doubt whether stock raisers andveterinarians would be much interested in co-operating in the control of the intermediate hosts ofsnail-borne diseases.

DISEASE CONTROL

Factors related to the economic developmentof the country will be discussed in the followingmajor section, but it can be said here that naturalresources are meagre, that there is a lack of sufficientrainfall in much of the country, and that generallythe soil is.poor. In spite of these adverse features,the population is relatively dense and as a result theaverage living conditions, educational attainments,etc. tend to be quite low.

Medical and health servicesThe work of the Ministry of Public Health and

Population is carried out primarily by the "Assist-ance Medicale Africaine " (AMA) and the "Servicedes Grandes Endemies " (SGE), formerly the SHMP.

There is also a programme connected with theschools but it is closely related to the AMA and theSGE. The functions of both major units are impairedby lack of funds nd personnel. In 1959 planscalled for 43 medical officers, 21 medecins africains,three pharmacists, 26 midwives, and a total of 753nurses, technicians, etc. Not all of these positionswere filled at the time of the survey. The majorhospital was in Bobo-Dioulasso, but a large one wasunder construction in Ouagadougou at the time ofthe team's visit. There were 22 medical centresthroughout the country and all of these except threewere visited by the team. In addition, 188 treatmentcentres, maternity clinics and dispensaries weredistributed in 37 administrative units throughout thecountry. In nearly all the areas the shortage ofpersonnel made it imperative for the SGE and theAMA to work together and often the medical officerpresent was in charge of both programmes. Inmany of the smaller centres, the presence of a singlemicroscope in one of the local SGE and AMA unitsdetermined who made the microscopic examinationsof blood, urine, etc.

In theory the SGE units are in direct contact withthe villages and rural populations, but they areprimarily concerned with leprosy, trypanosomiasisand the treponematoses. The AMA is in charge ofhospitals and related medical services. In parts ofthe country where there are nomads, however, theSGE is the principal medical service. There wassome feeling by certain authorities that with themarked decline of trypanosomiasis and the trepo-nematoses, the SGE could use its mobility andvillage contacts in attacks on such diseases as malaria,bilharziasis and other helminthic infections. If thisshould be done it would require considerablereorientation, additional support and personnel.The physicians are oriented primarily towards theuse of chemoprophylaxis and treatment as prevent-ive medicine techniques; the technicians and nurseshave had relatively little practice in the examinationof excreta; and sanitarians are non-existent. In thepast, studies made on the helminthic diseases havebeen of only passing interest because chemoprophy-laxis did not lend itself to an effective controlprogramme, and after some information had beenobtained on prevalence and distribution, that wasessentially the end of the matter.

In one of the documents obtained from theMinistry of Information, the statement was madethat the AMA and SGE saw or visited a total of2013 115 persons in 1959, with nearly eight million

17

D. B. MCMULLEN & J. FRANCO1TE

consultations. With the number of personnelavailable, even when all levels of training are con-sidered, it is obvious that the work load was sizeable.In order to accomplish this Herculean task shortcuts had to be taken and, while the total number ofpersons examined and of consultations is impressive,there is practically no information available ongeographical distribution, factors influencing theepidemiology of each disease, prevalence, etc.Until data of this type are available, it will beimpossible to set up basic control programmes or tomake reasonable judgements on the relative import-ance of the various diseases. This is particularly trueof intermediate host and vector-borne diseases,where transmission is directly associated with thehabitats of the hosts and vectors and with humancontact.The Ministry of Health does not have personnel

trained in public health engineering, environmentalsanitation, or public health education. Rural andurban water supplies are the responsibility of theMinistry of Public Works but no one on the staff ofthat Ministry has been trained in sanitary engineer-ing. There was some interest expressed in attemptingto correct this deficiency by giving special trainingin this field at the School of Public Works in Bamako,Mali Republic.

Environmental sanitationThe ultimate solution to the bilharziasis problem

and that of the control of other filth-borne diseasesmust be based on improved environmental sanitation.However, this approach requires the co-operation ofthe people, and this is difficult to obtain in areaswhere the general educational level and the averageannual income are low. Even under ideal circum-stances, marked improvement of conditions andreduction in the prevalence of such diseases with thisapproach could not be expected to occur in less thana generation. This means that other measures mustbe used in the interim, but it should be emphasizedthat, regardless of when an environmental sanitationprogramme begins, there will be an interval duringwhich expensive, repetitive measures will have to betaken. The longer it takes to initiate such a pro-gramme, the longer these measures will be required.

Water supplies. In the rural areas, especially atcertain times of the year, water of any kind is often inshort supply. Observations in the field showed that,as a result, almost anything wet will be used. Tothose who have never been driven to the extremity ofusing such sources, they appear incredible.

To help correct this situation, the Ministry ofPublic Works has a well-digging programme anddams are being built to store run-off water. Theformer will provide deep wells with adequatelyprotected heads, which should provide better waterthan the commonly used shallow depressions thathave been scooped out in low places. However, inone instance it was observed that the clear waterfrom a well and its head were being used for thewashing of clothes. The wash water was allowedto go back into the well, while in a near-by streambed a muddy pool, which was supplied by seepage,was used for drinking. In other areas, with evenless adequate water supplies, the people oftenbelieve that they have sufficient water and marvelat the concern of the authorities who wish to digwells. Plans include the provision of 1000 villagewells and 250 small dams.

There are many wells of varying depth and degreesof contamination in major centres such as Ouaga-dougou and Bobo-Dioulasso. Polluted streams insuch centres also serve as water sources. In theformer city there are three dams relatively closetogether in the same watershed. The reservoirslightly above the city serves as the municipal watersupply. The watershed and the reservoirs are onrelatively flat terrain and the water is collected froma rather heavily populated area. The two lowerreservoirs are along the margin of the city and receivedrainage from a system of ditches and stream bedswhich serve as open sewers, which more or lesscarry away waste. With the rapid growth of the cityand the resulting demand for water, plans have beenmade to channel the sewage to a point below thethird dam. Wells and other sources serve as watersupplies in other population centres and filtrationor chlorination is required before it can be consideredpotable.

Borrow pits. With the rapid growth of Ouaga-dougou, there is an increasing demand for clay forbuilding houses. The numerous shallow pits fromwhich the clay comes catch water and often makesuitable habitats for mosquitos and snails.

Urban sanitation. There are no sewerage systemsin the country. Ouagadougou does have two publiclavatories for a population of 70 000. Refuse fromhouses and markets tends to accumulate and itoffers harbourage for flies and rats. Pollution byhuman waste is very common.

This listing of the undesirable features about thesanitary conditions in the major population centres,

18

SURVEY BY WHO BILHARZLASIS ADVISORY TEAM IN UPPER VOLTA

and the need for potable water supplies, mayappear to add up to a hopeless total of items thatneed attention. Actually these items simply repre-sent the long-range steps that any poorly developedarea must take to improve the health and living con-ditions. Eventually the larger population centres willrequire water supply systems with treatment plants,sewerage systems that will protect the water supplies,channelling of streams, drainage and grading,garbage disposal, etc. These developments will notbe practical without provision for maintenance ofthe structures and for education of the public to apoint where they can appreciate their value andco-operate in their use. One suggestion that iscommonly made is that such educational pro-grammes should start with the teachers and passthrough them into the schools. On the surface thisappears to be a good idea but the following quotationfrom the Report of the Commission of Enquiry intothe Health Needs of the Gold Coast (1952; para. 167)may be considered pertinent to Upper Volta: " Sofar as prevention [of disease] is concerned, instructionin hygiene is a step in the right direction, but theteaching of hygiene in the schools without even therudiments of sanitation is clearly of little value andthe practice of hygienic habits is impossible. It isequally of little use teaching schoolchildren hygieneor treating their preventable diseases, if after schoolthey return to a village without any sanitary ameni-ties". At present the schools and villages do nothave the sanitary amenities and only 9% of thechildren attend school. Changes that fill basic needswill be required before the more advanced ones canbe dealt with. In a discussion of the " unhappyparadox " of agricultural overproduction in someparts of the world and substandard nutrition levelsin others, Harrar (1961) makes the followingstatement: " ... the future economic growth ofmany of the less well-developed nations of the worldwill depend precisely upon the rapidity with whichtheir citizens can be trained for the multiplicity ofresponsibilities related to agricultural production,distribution, marketing and utilization and attend-ant occupations ". With only a small percentage ofthe children attending school, this general problem ofeducation is irrevocably related to the economy andthe health of the people in Upper Volta.

Rural sanitation. This is non-existent but duringcertain seasons the combination of rapid desiccationand the action of the sun must be quite effective inreducing the transmission of some filth-bornediseases. Next to the provision of a water source,

that of safe bathing and laundering places and ofsimple waste disposal facilities should be the firststep to be taken in the villages. As has been indicatedabove, maintenance and proper use of such facilitiesmust be accompanied by health education or theywill be a waste of effort. There is a plan in UpperVolta for a three-year course for 14-17-year-oldadolescents in the rural areas. This is intended toprovide practical training in agricultural methods,etc. It may be that elementary instruction in hygiene,sanitation and disease prevention could be included.

AGRICULTURAL AND WATER RESOURCE DEVELOPMENT

The average annual rainfall in the southwesternpart of the country, according to a 1958 report of theHydraulics Service, is 1253.7 mm and it decreases to518.4mm in the northeast. In the former the monthlyaverage ranges from 2.7 to 262.9 mm, with Novem-ber through March essentially without rain andwith the greatest fall in August. In the northeastthe pattern parallels this but the monthly averageranges from 0 to 182.7 mm, with the months ofOctober through May essentially without rain. Inmany areas bare rock is exposed, in others the soil isrelatively impermeable and has little vegetation forcover. As a result the rain, which tends to come inviolent downpours, causes a great deal of erosion andmost of the water is lost in flash floods. The effect ofthese seasonal fluctuations on the intermediate hostsand the transmission of bilharziasis have beendiscussed in a previous section.

In the circumstances it is obvious tiat improvedagricultural methods, soil conservation, flood con-trol, and water storage are primary problems inUpper Volta. In the past thirty years the populationpressure, poor farming methods, soil erosion, over-grazing, etc. have resulted in the extensive encroach-ment of desert flora from the north. In the vicinity ofOuahigouya there is an excellent three-year-old soiland water conservation programme which involvescontouring and increased soil percolation. At present7000 ha are included in this programme and theresults obtained demonstrate its value. Unfortun-ately it will cover only a relatively small area, incomparison with what needs to be done. It has beenestimated that 1.5 million ha, with a population ofthree million people, should be included in such aprogramme within the next twenty years.With contouring and increased water absorption

by the soil, this project tends to eliminate the accu-mulation of surface water for long periods, and no

19


snail breeding and bilharziasis transmission siteswere observed. However, a dam and reservoir arebeing planned for the area and may provide suchsites unless precautions are taken.

In regard to arid and semi-arid areas, it has beenshown repeatedly in Egypt, Sudan, SouthernRhodesia, Congo and elsewhere that the spread andintensity of bilharziasis increases from 1 %-IO% to35 %-80% in areas where water conservation andirrigation projects provide snail habitats and extendthe season of transmission. Some of the agriculturaland irrigation methods reported by the WHOBilharziasis Advisory Team 1 in Ghana, Kenya andIraq appear to reverse this trend. This has beendone by careful water management and a reductionin the amount of human contact with the water.

Bilharziasis also flourishes in areas where there istoo much water, e.g., marshes, swamps, seepages.Because of the flat terrain, Upper Volta has suchareas, in spite of the long dry season. In this typeof area, drainage and land reclamation tend toreduce the number of snail habitats. After suchmeasures have been taken, residual snail coloniesthat might remain could be controlled by improvedagricultural methods and molluscicides.

It was stated that an inter-ministerial organizationexisted in Upper Volta for the over-all planning ofsuch projects. The personnel directly involved insuch plans were quite aware of the importance ofsanitation and disease control measures but therewas little evidence that practical steps had beentaken. In several countries surveyed by the team,special funds have been allocated for this purpose.It was stated that in Upper Volta funds for resourcedevelopment were difficult enough to obtain andthat there was no obvious source for the support ofthese less tangible aspects of projects.

Agricultural practicesWhile the agricultural methods in general use

appear to be primitive, they supply food for arelatively large population. Millet, maize, yams andrice are common staples, but the last of these is oftenlooked upon as too expensive to eat and is for saleonly to the more prosperous segment of the popula-tion. In general, there tends to be a relative abund-ance ofproduce in the southwest, but lack ofcommu-nication and buying power in some other sectionsprevent an equitable distribution. In the morefertile, low-lying sections mounding or furrowing,

' See the article by McMullen et al. on page 25 of thisissue.

done by hand, is used to retain water or to obtaindifferent degrees of moisture suitable for variouscrops. In the drier and higher parts of the country,often only small holes are hacked into the hard soiljust before the rainy season and a few seeds aredropped in each one. The use of ploughs and draughtanimals was observed only at the Lantaogo co-operative scheme, near Fada N'Gourma.

Irrigation, flood control and drainageIrrigation. With the exception of the marshy

plain in the vicinity of Segedougou and in theSourou Valley, all irrigation-agricultural schemesplanned or in operation are on a small scale. Thesmall schemes usually consist of low dams across avalley and the water stored is used to supplementrainfall. Such schemes are the responsibility of theRural Engineering Service of the Ministry of Agri-culture, and the resulting reservoirs will be discussedin a later section in connexion with similar bodies ofwater. It was indicated that in some parts of thecountry the people were not sufficiently versed asagriculturists to take advantage of these schemes.Because of the season during which the survey was

made, little could be learned concerning the effect ofirrigation schemes on snail distribution, except insome of the reservoirs. It will be noted in Table 8that there was evidence of snail populations inalmost half of those examined. None of the canalswas in use and at the time of the survey snails werenot found in the few examined.The irrigation methods used in established schemes

are of two general types. At Segedougou, Loumanaand Douna earthen dams and dykes are used toretain water in low, flat flood-plains. In such areasthe people use mounds or ridges and the naturalcontours as the basis for the distribution of cropsand the adjustment of water levels. In effect, this is atype of basin irrigation. In the first of these areas,the people have not fully accepted this method offarming and only 500 ha out of the 2000 availableare being farmed. A total of 5000 ha could be madeavailable there.At the Dabesna, Lentaogo and Malba schemes the

water in the reservoir is used to supplement rainfallfor crops below the dam. Lateral canals from eachend of the dam can be used for irrigation and theformer stream bed serves as a drain. In the last twoschemes they also use the floor of the reservoir forcrops as the water recedes, using methods somewhatsimilar to those described in the previous para-graph.

SURVEY BY WHO BILHARZTASIS ADVISORY TEAM IN UPPER VOLTA 21

Nothing is known about the effect these schemeshave had on the prevalence of bilharziasis in theassociated population. As will be seen in Table 1,however, surveys made in 18 villages in the Sege-dougou area in 1956-57 showed that bilharziasisinfections ranged up to 67%. At Malba, 54% ofthe schoolchildren examined were infected withS. haematobium, and in a superficial survey of 23persons at Douna, 14 (61 %) had haematuria. Nosurveys have been made in the other areas mentionedbut, as will be seen from Table 1 and the map,irrigation schemes are not necessary for the supportof heavy bilharziasis infection rates. Since there arenew schemes which have not yet had a chance tochange the infection patterns in village populations,it should be possible to study this relationship inUpper Volta. In such a study organized surveysshould be made of a cross-section of the populationin an area where the scheme is not more than twoyears old, or in an area where such a scheme is to bebuilt. Periodic checks, especially in children under10 years of age, would give the data required. Suchsurveys should be of as much value to the plannersof the schemes as to the Ministry of Health, sincetheir success depends partly on the health of thepeople involved.

Sourou Valley. An irrigation, flood control,agricultural scheme has been proposed for the SourouValley in the northwestern part of the country.This is being discussed separately from the otherschemes because it involves more than twice as greatan area as all the others combined and, if it is com-pleted, an estimated 48 000 people would immigrateinto the Sourou.The part of the valley which would be affected

extends from the junction with the Black Volta forabout 110 km northwards and into the Mali Repu-blic. It contains 23 000 kM2, of which 36 000 hacould be irrigated, and an additional 65 000 ha couldbe cultivated. At present only 10 000 ha are undercultivation. The gradient is very low, about 3-4 cmper km, and a natural dike prevents complete drainageinto the Volta. The hydraulic characteristics of thearea are affected more by the rainfall in the BlackVolta watershed and the annual flood than by thelow annual fall in the Sourou drainage system, wherethere is a seven-month dry season and not morethan 800 cm of annual rainfall. When the BlackVolta is in flood (August) an average of 350 millionm3 of water flow into the Sourou and cover about25 000 ha. At present 110 million m3 flow back intothe Volta and the remainder is accounted for by

evaporation, agricultural use, percolation, etcDuring the lowest level, 4000-5000 ha remaincovered by water. The fish caught in the Sourou,especially during the period when the water is low,account for about 20% of the established value of theproduce from that area. Estimates of the annualcatch vary from 300 to 800 tons. The area is alsovery important because some 40 000 head of stock arebrought into the area during the dry season.The present plan includes a dam of the Volta, a

canal from the reservoir to the Sourou, and a seconddam with gates on the latter to regulate the waterlevel. All water control would be by gravity and itsflow could be used to generate power. Accordingto various calculations this scheme would be econo-mically feasible, with an increase in gross annualvalue of the produce from 85.2 million to 1214.2million francs CFA.1 By some, the Sourou is con-sidered the country's principal potential resource.It is of interest that one of the reports on the Sourouplan refers to the data obtained by the SGE surveyteam, discussed in a previous section. In spite of theprevalence of various diseases reported, it is impliedthat there is nothing to be alarmed about on thatscore. This is also in spite of the fact that the popu-lation of the valley would be expected to increasefrom 22 000 to about 70 000. Just the concentrationof this population in the area would markedlyincrease the amount of the faecal veneer and thechance of filth-borne epidemics. In the budgetestimates prepared, nothing is shown for diseasecontrol, community development, or environmentalsanitation. It was, however, stated that the inter-ministerial committee would correct this oversightwhen the final plans were made.

Dams, causeways, etc. Such structures come underthe jurisdiction of the Hydraulics Department andRoad Building Service of the Ministry of PublicWorks, and the Rural Engineering Service of theMinistry of Agriculture. Between 1940 and 1950 thelast of these agencies constructed about 100 damsbut many were not properly built and others were ofno use because the hydrological data were inade-quate. Only a small number of these are still in use.A new programme was started in 1955, and 15 newdams are in use, 19 are under construction, and eightmore are planned for 1961. A map of the distribu-tion of these dams showed that many of them are inareas where bilharziasis is highly endemic. There isan increasing demand for such dams and 255

1 Frs CFA 100 = S0.48.


requests are on file for consideration. The pro-gramme that has been planned would cost about7000 million francs CFA. The Hydraulics Depart-ment has 12-15 dams under its supervision.The dams are financed by the Government, or in

some cases the villagers pay one third of the expense.Once a dam is constructed, it is maintained by thevillage but it is inspected by officials from time totime. There is no pre-storage clearance of the reser-voir, silting and aquatic vegetation are not consideredserious problems, and cleaning of the bed during thedry season is not done. Most of the areas are soflat that water take-offs at the base of the dams areimpracticable, but wells at the base are sometimesused. Fencing the large, shallow ponds is consideredimpracticable. The height of the dams ranges from2.5 to 3.5 m and the reservoirs vary from 1 ha to 765ha in extent. Some contain water the year round,but many of them are often dry for two or moremonths. Some of the former produce considerablequantities of fish.

It was stated that there was relatively little loss ofwater from reservoirs through the soil. The dailywater loss by evaporation was said to be about 1 cm.It was thought that the use of cetyl alcohol andsimilar materials to reduce evaporation would betoo expensive.

In addition to the types of dam mentioned above,many causeways have been built across low-lyingareas, the tops being used for roads. The watercaught behind these serves much the same purposesas the other types of reservoir and also as snailand mosquito habitats.

Fish-ponds. There are about 100 fish-ponds in thecountry, and, because of the seasonal flow in thestreams, these tend to be confined to the southwesternsection. They are supervised by the Water andForests Service. The ponds visited at Tin consistedof a series of six, and there were 42 at Beregadougou,near Banfora. In the latter case the water was quiteacid and the fish did not thrive. The people are notmuch interested in fish-ponds and prefer to buy driedfish which come from the Niger River. As indicatedabove, some of the reservoirs are sufficiently per-manent to support fish.

Roads, bridges, etc. While travelling over about4000 km of the roads in Upper Volta, it was possibleto observe various man-made snail habitats thatresult from the building of roads and accessorystructures. The causeways have been discussed inthe section on dams. In building these and in

placing culverts, the natural drainage has oftenbeen obstructed, partly from an urge to conserve asmuch water as possible. These installations do,however, offer breeding sites for various diseasevectors. Snails and mosquito breeding sites also werefound in seepages and pools below such structures.Engineering methods could be used to eliminate atleast some of these habitats, while retaining theadvantages of water conservation.No snail habitats were found associated with

bridges.

SUMMARY AND CONCLUSIONS

Distribution and importance of bilharziasis in UpperVoltaWhile many of the data available on bilharziasis

in Upper Volta cannot be used to determine theprevalence and precise distribution of S. haema-tobium, there has been a sufficient number of specificsurveys to give more information than is availablefrom neighbouring countries. An analysis of thedata from these surveys indicates the following:

(a) The infection is generally distributed through-out the major watersheds and administrativedivisions of the country. Data on the prevalencefrom various villages, however, show that seasonalhydrological and geographical factors limit themost important transmission sites. Concentration ofcontrol measures on such sites would be the mosteffective approach.

(b) The infection is most common in children,and slightly more prevalent in adult females than inmales.

(c) It is estimated that about 50% of the popula-tion, or more than 1.5 million people, have theinfection at some time during their lives.

(d) Nothing is known about the residual effectsof these infections but various types of chronicurogenital disturbances commonly appear in theMinistry of Health Reports.

Lack of sufficient data from faecal examinationsmakes it impossible to estimate the prevalence andimportance of S. mansoni. Evidence from a fewrecords and the scattered distribution ofBiomphalariaindicate that this parasite is probably more commonthan health authorities suspect.There are indications that the prevalence and the

intensity of the infections of both parasites willincrease with the development of agricultural andwater resources of the country. For this reason, it is

22


concluded that bilharziasis has a direct bearing onthe country's economy.

Statistics and recordsWith some additional effort it should be possible

to obtain a great deal more information, from thegreat amount of work being done, on the prevalenceand distribution of the various communicablediseases in countries such as Upper Volta. Withoutsuch data it is virtually impossible to plan a practical,epidemiological approach to the control of many ofthese diseases. This is particularly true of thosediseases transmitted by intermediate hosts andvectors.

SurveysIf the scope of these efforts is expanded to include

studies on the intestinal protozoa and helminths,it will be necessary to consider the following:

(a) Surveys in the human population(1) Select representative areas for initial surveys.(2) Include urine and faecal examinations of

specific population groups e.g., a cross-section ofthe population in selected areas- to determine theage distribution of the infections and, amongschoolchildren, to obtain baseline data for theevaluation of control measures.

(3) Record age of each person examined.(4) Record domicile of each person examined.(5) From data above, determine the important

foci of transmission.(b) Snail surveys. If special emphasis is to be

placed on bilharziasis, snail surveys should be made.In Madagascar and Ghana the mobile units havedone the following:

(1) Observe water-use habits of people in eacharea surveyed.

(2) Collect snails from bodies of water wherehuman contact is common, determine typespresent or send them to a specified place foridentification, obtain quantitative data on snailpopulation density during different seasons.

(3) Examine snails for the mammalian type ofschistosome cercariae.

On the basis of the above, it should be possibleto determine the places where the greatest controlefforts should be expended, and the type of controlmeasure or combination of measures best suited foreach situation. The assessment of the value of these

measures would be made by snail population studiesduring the first year or two, then after three to sixyears a resurvey of the human population, especiallythose of school age, would indicate the effectivenessof the control programme.

Methods of control

The lack of truly efficacious drugs for bilharziasisforces the conclusion that special attention must bepaid to the preventive aspects of the control of thisinfection. It has been indicated in the report thatsnail control, engineering methods, and environ-mental sanitation can be used. In some cases thesecan be combined with soil and water resourcedevelopment, but it should be emphasized that inarid areas the storage of water and its use forirrigation are apt to increase the prevalence andintensity of the disease. Because of the broadnature of the health problems, it is concluded thatbilharziasis control in many countries shouldprobably be considered in relation to other filth-and vector-borne diseases. This general approachwill require some reorientation of the thinking andimplementation of the programmes of the publichealth agencies. The types of measures can besummarized as follows:

(1) Snail habitat elimination. This also assists inthe control of some of the arthropod vectors ofhuman disease.

(2) Use of molluscicides on the residual colonies,when all transmission sites cannot be eliminated.

(3) Improvement of water supplies. This will tendto reduce human contact with polluted, snail-infested water. It should be combined with theconstruction of safe bathing and washing places.Such measures also reduce the transmission of otherfilth-borne diseases.

(4) Proper disposal of urine and faeces. This willprevent the infection of snail populations and thepollution of water supplies.

Pilot control project

Past experience indicates that the establishment ofa pilot control project is the best way to utilizelimited funds and personnel, and it prevents thedissipation of effort to unpractical limits. As a resultof this particular survey, Bobo-Dioulasso appears tooffer many elements that one would look for inselecting such an area. It is a large population centrewith filth- and vector-borne disease problems, and

23


S. haematobium, S. mansoni and their respectiveintermediate hosts are present in the vicinity. It is anarea where environmental sanitation and eliminationof snail colonies could be used to an advantage, andmolluscicides could be tried on residual colonies.Laboratory facilities and living facilities for thestaff would be available. The preliminary studies, theinstitution of control measures in such an area, andtheir evaluation would require at least five years.However, the benefits of a pilot control projectwould not be localized, since the methods tested andadapted could be applied more efficiently and at aminimum of expense in other irhportant foci.

Water resource development and disease controlIt is concluded that public health surveys should be

a part of the preliminary investigations made in areaswhere the development of water and soil resourcesare being contemplated. The data obtained should beused as a part of the material needed to determinethe feasibility of the project, and to provide informa-tion that can be used to estimate the public healthrequirements. It must be recognized that the mea-sures necessary for safeguarding the health of thepeople are part and parcel of the over-all projectand must be provided for in the same way as detailson soils, hydrology, etc.

ACKNOWLEDGEMENTS

The authors are deeply indebted to many individuals inUpper Volta for their assistance and co-operation inobtaining the basic information required for this report.In this regard, special mention should be made ofDr Lambin, Dr Pascal, Dr Roux, and the MedicalService personnel in the various areas visited.

In addition to the unpublished documents mentionedin the text, the following reports were also kindly placed

at our disposal: reports of the School Medical Service forthe years 1947-53, annual reports of the Health Servicefor the years 1949-59, annual reports of the variousmedical centres visited, reports in the files of the CentreMuraz, and two reports by the Hydraulics Service of theMinistry of Public Works on the proposed developmentof the Sourou Valley.

RJESUMI

L'equipe consultative de l'OMS sur la bilharziose aeffectue une enquete sanitaire en Haute-Volta (mai-juin1960) qui a montre un pourcentage eleve d'infestation aSchistosoma haematobium: 500% des habitants, soit1,5 million de personnes environ, sont atteints 'a unmoment quelconque de leur vie. Les enfants surtout sontparasites, et les femmes un peu plus souvent que leshommes; les sequelles de cet etat de choses sont malconnues, mais on note la frequence des affections genito-urinaires vues i F'h6pital. Par ailleurs, les examens deselles ont et trop peu nombreux pour evaluer la fre-quence de S. mansoni et l'importance de son r6le. Cepen-dant, au vu de quelques observations et de la distributionde Biomphalaria, on peut supposer que cc parasite estplus repandu que ne l'admettaient jusqu'ici les autoritesde sante publique. Le reperage des habitats occupes parles mollusques et 1'6tude de la repartition des foycrs de

bilharziose ont montr6 que la plupart des plans d'eausont infestes; en revanche, les sites de transmissionseraient assez nettement delimites. Ce seront la deselements a retenir, au meme titre que les divers facteurssaisonniers, au moment de mettre sur pied la campagnede lutte contre la bilharziose.Le tableau sanitaire du pays dans son ensemble devra

etre etudie en meme temps que l'assainissement du milieu,l'approvisionnement en eau, le developpement de l'agri-culture avec la construction de barrages et de systemesd'irrigation qu'il entraine. Toute une serie de problemesde sante publique reste a resoudre si l'on veut que lalutte contre la bilharziose ne soit pas vouee a l'echec.Compte tenu des ressources actuelles, il serait logique derealiser tout d'abord un programme-pilote, et la regionde Bobo-Dioulasso semble la plus indiquee pour la miseA execution de ce projet.

REFERENCES

Deschiens, R. (1951) Bull. Soc. Path. exot., 44, 350, 631Gold Coast. Commission of Enquiry into the HealthNeeds of the Gold Coast (1952) Report of the Com-mission. . ., Accra, Government Printing Department

Harrar, J. G. (1961) Science, 133, 671Marill, F.-G. (1957) Bull. Acad. nat. MMd. (Paris), 141,

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report on preliminary survey by who bilharziasis advisory

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