Intercountry project for the feasibility study of an onchocerciasis control campaign in the Senegal river basin area (project ICP/MPD/07)

Efie 1.7 ORIGINAL: FRENCH 7 l 7 I 7 7 ? INTERCOUNTRY PROJECT FOR THX FEASIBILITY STUDY OF AN ONCHOCERCIASIS CONTROL CAMPAIGN IN THE SENEGAI RIVER BASIN AREA (PRoJEcr rce/veo/oot1 INTERIM REPORT a' t' f r' I October 1980 JPCI.7 Page 2 CONTENTS "( 1 tPage t I I Sunrnary . 1. Introduction. 3 5 3.1 3.1.1 2 J 3.2 3.2 J.J 3.3 Presentation of ttre Project area Project activities Data already avaiLable Entomology .(a) Identification and distribution of the vector species . .(b) Distribution of pre-imaginal sites(c) Dynami-cs of the vector population and parasite transmission Epidemio logy Hydrobiology Hydrolory CarEography Socioeconomic aspects Previous campaigns . . Data obtained by the Project . I Entomology .(a) Distribution of Iarval sites(b) IdentificaEion of species of the S damnosum complex(c) Population dynamics and transmission(d) Limits of E.he distribution zone of the savanna vectors 2 Epidemiology . 3 Hydrobiology . Data still to be obtained - deadlines for obtaining them . . I Entomology(a) Distribution of vectors .(b) Identification of species of the sum complex in order to determine the boundaries of the Project(c) Population dynamics and transmission(d) Vector susceptibility or resistance to insecticides Epidemio logy(a) Onchocerciasis(b) Other diseases Socioeconomic aspects . 4. Onchocerciasis control campaign 8 8 8 8 9 10 11 20 20 20 20 20 2L 2L 2L 3.1 3.1 3.1 3.1 3.1 3.1 )n 1a ) .3 .4 .5 .6 .7 16 L6 L6 L6 L7 L7 L7 18 I8 18 L9 19 20 20 20 L7 \ s. d 3.3 .2 3.3.3 n 4.L 4.L.1 4.r .2 4.L.3 4.L.4 4.t.5 L+.2 4.2.L L)? 4.2.3 4.2.4 4.3 4.4 4.5 Logistic resources . . Insecticide . Infrastructure for aerial treatments Road network . Hydrome tric ne t\,Jork Radio communications . Evaluation . . Entomological evaluation . Epidemiological evaluation Hydrobiological evaluaLion . . Socioeconomic evaluati-on . Research . . Training . . Prograrmre structure Financial situation of the Project Final report Conc lusion air operations 22 22 23 25 26 28 28 28 30 30 31 31 32 JJ 35 35 38 , 5 6 7 8 't IDocumenEs consulted 39 t a'l 1 7JPC1.7 Page 3 SUMMARY The Project for the feasiAilit,y study of an onchocerciasis control campaign in the Senegal River Basin area (7CP/WD/OO7 ) was set up at the requesE of four West African countries: Guinea, Guinea-Bissau, Mali and Senegal. The Project is financed by Belgium, the Netherlands, the United States of America and the United Nations Development Fund (UNDP), the funds provided toEalling US$ I 150 OOO. The purpose of the Project is Eo draw up a plan for onchocerciasis control in these four countries and to estimate the cost of such control. It has been decided thaE Ehe progranme would be limited to the control of savanna onchocerciasis, which is Ehe most severe and incapacitat.ing form of the disease. The area covered by the Project would therefore be 37O OOO kmz. The interim rePort presented here suumarizes the inforoation available up to 31 July 1980. It outlines the suggested strategy for the control carnpaign and gives preliminary indications on the resources of manpower, equipment and supplies that will need Eo be rnobilized. As regards entomology, it would seem Ehat there is sufficient knowledge already to determine the northern and western boundaries of the programe. In the east the prograynme would border on the Onchocerciasis Control Programe in the Volta Basin area (OCP). It therefore remains to define Ehe southern boundary, which could pass through Sierra Leone and Liberia. Ihis boundary witl be determined by the studies now in progress on the distribrrtion of the vectors of savanna onchocerciasis. Itre fult results of these studies are expected ear I-y in 1981 . The data on the geographicat distribution of the vectors, their bioecology and their transmission potential are sufficiently detailed for plans of campaign to be prepared already for Mali and Senegal. In Mali the results for the rainy season show that transmission is hypoendemic along the northern boundary, becoming mesoendemic and then hyperendemic further to the south. In Senegal the surveys have shorvn that Eransmission of the parasite can reach an extreuely high leve1. A transmission potential of 3OOO infecting larvae of Onchocerca volvulus was observed in the month of August at the Niokolo-Koba encampment In Guinea data are plentiful for the upper basin of the Niger, but the data for the rest of Ehe country need to be completed so that plans of carnpaign can be prepared. Additional data will also be needed for a proper assessment of the problem in Guinea-Bi-ssau This additional information is expected to becorne available in the first quarter of 1981. As regards epideuriology, Ehe data already available are sufficient to estigate Eheprevalence and severity of the disease in Guinea-Bissau, l,lali and Senegal. In Guinea thedata are satisfactory for Ehe Upper Niger basin but will need to be supplemented by the end of the first quarEer of 1981 for the Fouta Djalon region. The data as a whole will form an adequate basis for planning the evaluation of the reduction in endemicity and the effects of a vector control campaign, Prevalence is very high along the rivers (hyperendemic zones) in the four countries sEudied. The rates are 72.2% for the Dinguiraye region (Guinea),69.7% at Sonaco (Guinea- Bissau) , 76% bei.r,teen Bamako and Koulikoro (Mali) and 64% ln Ehree arrondissements of K6dougo u d6partement (senegal). Blindness rates of 5-107" are not uncoE[tron; there is even one village in lr{ali wiEh a rate of L8.3% rhe information on the other diseases rcill also be supplemented. As regards E.he socioeconomi-c aspects, little information has been collected so far.A socioeconomic mission from the French Office for Scientific and Technical Research overseas(oRSToM) should make good this deficiency, however, and provide a report in February l9gl. t ) ? F r' I -> ) I JPC1.7 Page 4 The control strategy being considered at present is similar to the one currently being applied by OCP, i.e. destruction of the vector larvae by means of insecticides sprayed from the air, irmrediaEe evalualion of the effects of the treatments on the insect vectors, and longer-term evaluati-on of the effects on the prevalence of the disease. In order to apply a strategy of this kind, it is essential to ensure that resources are available. logis tic (a) Insecticide: the amounEs of insecticide needed have been calculated for part of the zone (Ma1i, Senegal) where the planned annual consumption is I38 3OO litres of 20% emulsifiable concentrate with the characteristics of the temephos formulation used by OCp. For the remainder of the Project area, the quantities of insecticide will be calculated when Ehe aerial reconnaissance of Guinea and Guinea-Bissau has been compleEed (OcEober 1980). At that time, it will also be possible to determine the type of aircraft to be used, together with the treatnent circuits and the points for refuelling and refilling insecticide. (b) Aerial infrastructure: an inventory of airfields, fuel supply points and air traffic regulations has been compiled; 18 landing strips have been listed in the Project area. (c) Road netswork: the roads, the condiEion of which governs Ehe entomological, epidemiological and hydrobiological evaluati.on acEivities and the land-based logistic support for the air operations, are being evaluated. IE already appears that the prograrmoe will have to overcome very great problems regarding overland travel. (d) Radio comunications network: a radio neEwork is planned to link up the various operations and decision-making centres. Approaches have already been made to the Inter- national Telecormunication Union and the reLevant national services, An agreement in principle to seE up such a network has been reached. (e) Hydrometric network: the number and siting of the water-Ievel gauges was considered satisfactory for the imrediate needs, which are to estimate the amounts of insecticide required for the campaign. However, the hydrometric network will have to be supplemented for the operational needs of the prograllme, when it will be necessary to know the flow rates of the watercourses sufficiently accurately Eo avoid applying too much or too tittle insecticide. A project for installing new water-level gauges and for recalibraEing some of the existing gauges has been proposed. It covers a total of 35 gauges: 23 new ones and L2 for recalibrating. An initial estimate of the needs for the evaluation activities has been drawn up (a) The entomological evaluation network should comprise five sectors and 19 sub- sectors. The sectors would be headed by entomologists and the sub-sectors by entomology technicians. (b) Epidemiological evaluation would be carried out by a team consisting of an epidemiologist, an ophthalmologist and a sociologist, assisted by the necessary technical staff. This team would visit a certain number of indicator villages disEributed throughout Ehe zone every two or three years. (c) Hydrobiological evaluation could be entrusted to three national teams made up of experts on invertebrates and ichthyologists. These teams would carry out periodic checks on non-target fauna. (d) Socioeconomic evaluation would be under the responsibility of an economist and a public health adviser. A certain number of people from Ehe countries concerned by the Project have been given specialist training. This training effort will be conEinued so that the prograsme will have available the necessary sEaff and also to provide the governments with the naEional staff to .t ( 1 ( a ( ( t { (- q. '\ \ '{ ( i, 7 f JPCl. 7 page 5 cooperate wiEh the programme . This staff, depending on specialty and Level, could be given training in the universities, followed by cour:ses at the Medical Entomology Training Centre in Bouak6 for entomologists, at the Institute of Environmental Sciences in Dirkar for hydrobiologists, and at the WHO Centre in Lom6 for medi.cal doctors. This traini.ng could be followed by periods of practical work with OCP. The technical staff vould bc. given training at the Onchocerciasis Research Institute in Bouak6 or the lnstitute of Tropical African Ophthalmology in Bamako or the InEer-State Fishery Training Centre in Bouak6. Here again periods of practical work with OCP could be considered. The research associated with this prograume should be restricted to the specific operational problems of the region. At this sEage in the study, two types of structures could be considered for the programme, depending on whether it is regarded as an entity independent of OCP or as an extension of that Prograrmre. These two options will have to be carefully studied and presented in the final report, indicating Ehe advantages and drawbacks of each . The financial situation of the Project on 3l July 198O is as follows: income US$ 407 143, expenditure US$ 328 229. The UNDP contribution for I98O of US$ 27 Ooo is not included in this balance. The interin report aLso presents a proposed outline for the final report on the Project In conclusion, it may be stated that onchocerciasis is hi.ghLy endemic in the four countries concerned and occurs in its most severe form in all the savanna areas of these countries, except for the coastal region. The human and hence economic consequences of this situation are extremely serious. Control of the disease is regarded as possible on the basis of the existing data or the data to be obtained in the next few months. The programme under consideration would have the advantage of being weIl protected from reinvasion, because it would cover the entire distribution area of the savanna vectors to the west of the OCP area. It could be organized on the same basis as OCP for a sufficient period to enable the countries to continue their activities within the limits of Eheir financial resources. No estimate of the cost of such a prograrme can be given at the present time, but the expected health benefits would undoubtedly be very great. 1. INTRODUCT1ON The origin of the intercountry project for the feasibility study of an onchocerciasis control campaign in the Senegal river basin area goes back t-o the official request for implementation of such a projecE made by the Governments of Guj.nea, I'lali and Senegal at the fourth session of the Joint Coordinating CotrErittee (JCC) of the Onchocerciasis Control Caropaign in the Volta River Basin area (OCP) , in Kuwait in December 1977 . During the Thirty- first World Health Asseuibly (May I978) the Government of Guinea-Bissau officially asked to be included in the ProjecE fc:r a feasibility study. The Regional Director offered to carry out joint studies in Guine.r, wesEern Mali and Senegal, and made available an amount of US$ l5O OOO from his own Development Fund so that activities could be carried out in 1978. This sum is in addition to the tls$ 30 OO0 contributed by the Director-Genera1. Accordingly, WHO took the following steps A conmrittee consisting of Regional Office and Headquarters experts vras set up to attend to preliminary studies and planning. A team consisting of an epidemiologist and an entomologist r,ras formed to collect the existing data and to crganize some preliminary studies. ) l' ? I ) JPCt.7 page 6 - Headquarters and Regional Office specialists visited the countries in order to touch with the national authorities and coorciinate the acti-vilies. get in - National candidates of a1l disciplines /entomologists, physicians and technicians) \r/ere selected, and their training in the various disciplines and at different levels was organized. - Temporary advisers \rere recruited to sunrnarize the entomological and medical data for Mali and Senegal and the socioeconomic data available in Guinea, I"lali and Senegal. - Aerial reconnaissance of the entire area of western Mali and Senegal was organized and carricd out in September I978. Draft terms of reference for the feasibility study of an onchocerciasis control campaign in the Senegal river basin area were then submitted to the fifth session of the JCC, in l,om6, Togo, in December 1978 . Following rthe acceptance by the JCC of the proposals contained in Annex 7, wcf7g.l, ofthe report JCC/5 (terms of reference revised in accordance with the recoumendations made by the members of the JCC), an intercountry project ltCYfweofooT) was set up to cooperate wiEh the countries concerned in collecting relevant data for the preparation of a plan, with costings, for onchocerciasis control in the Senegal river basin area. The Pro.ject covers four countries: Guinea, Guinea-Bissau, Ilali (western part, Ehe eastern part being covered by OCP) and Senegal. Since the start of L979 offi.cial approaches were made to the countries and organizations that had shown an interest in the Project during the JCC session in Lom6, Togo, in order to obtain their financiaL support for this study. The negotiations resulted in contributions of US$ 600 ooo from the Llnited States of America, US$ 25o oOO from the Netherlands, US$ 2OO OOO from the United Nations Development Programrne (UNDP) and US$ lOO OOO from Belgium These funds were made available to the Project as follows: US$ 3OO OOO from the United States of America in May 1979, US$ IOO ooo from Belgium in December 1979, US$ 27 OOO from UNDP in Januarv l9BO, and US$ 25O OOO from the NetherlarLds in August 1980. In the meantiriL-, a visrt was made to the four countries concerned ; its purpose was topresent the Project and to discuss with the national authorities the facilities which would be required by Lhc Project to s311, out the additional surveys (overflight of the countries, frontier crossings, customs facillties, availability of fuel and aircraft, etc,). Ihe professional stafl of rl-rc Project rdere recruited, and equipment and suoplies were ordered and delivered to llamako, the headquarters of the intercountrv Project. A detailcd pl.rn of rctron and a timetable for implementation of activities were drawn up in December 1979. Since the initial project provides for a study Iasting Ewo-and-a-half years, sCarE.ing earLy iL-t 1979, the activities of the Project actually began almost a year behind schedulc.. At Ehc last scssirrn of the' Joint Coordinating Cormittee of OCP, held in Geneva in December I979, the hr11() Regional Director for Africa acknowLedged that because of administrat- tive constraints the feasibilitv study was somewhat behlnd in its activj-ties, but he assured the CormnitLee th.tL Lrver)I effort would be made to see that fhr. interim Project report requested by the JCC in Lom6, Togo, would be presented as agreed to the Joint Prograrure Cosmittee at the end of 198O. Because of the de'lay mentioned above, this interim report could not be completed in time to be distributt'd in September to the Expert Advistrr:y Comnittee (EAC) and then to the OCP Cournittee of Sponsoring Agencies . However, these two cotrmittees were informed of the progress of tl-re feasibi lity study in a document sumrarizing the activities of the Project. 't T ( \ I { I 1I I /t JPC1. 7 Page 7 The strategy envisaged in the present report makes very extensive use of the knowledge of onchocerciasis control acquired by OCP. 1t is also based on the provisional conclusions, presented to the EAC in September 1980, of the OCP Independent Conrnission studying the long- term prospects of the Prograuure. In view of the nature of the disease, the biological and ecological characteristics of the vectors, and the control methods currently available, any onchocerciasis control campaign must take the following factors into account: The lack of any suitable drug for mass campaigns means that transmission must be interrupted for a period at least equal to the lifespan of the parasite in man(I5 years) . Ihe ability of the vector females to migrate, resulting in the periodic reinvasion of treated areas, makes it necessary: - either to treat very extensive areas in order Eo reduce the effects of reinvasion; - or, where possible to extend of the savanna vectors, the campaign to the absolute limits of distribution It is on the basis of these criteria, particularly the last one, Ehat the preliminary studies for the onchocerci-asis control programure in the Senegal river basin area have beenplanned and in part achieved. The interim report describes situation on 31 July 1980. the progress of the feasibility study on the basis of the 2. PRESENTATION OE THE PROJECT AREA The Project covers the entire zone of savanna onchocerciasis located to the \"7est of theonchocerciasis conErol Prograrmne in the Volta River Basin area (ocp) . This zone representsan area of about 370 ooo krn2 and essentially concerns four West African countries: almost thewhole of Guinea, the eastern part of Guinea-Bissau, the southern part of western MaIi, andeastern Senegal including the extreme east of casamance. The northern parts of Sierra LeoneandLiberiamight also be incorporated in the Project if it is prorred that the vectors ofsavanna onchocerciasis breed there and if those countries so wish. rhe sudanian and guinean savanna extends over the majority of the project area. However,sahelian characteristics are found j-n the north, while the south is covereci by guinean forest.rn Guinea there is a mountainous region, the Fouta Djaron, which has distinct biogeographicalcharacteristics on account of its altitude. The climate in the Project area has two seasons, a dry seasorl and a rainy season. Theclimate differs from the north to the south in respect of the length of the rainy season andthe amount of rainfall. The rainy season is very short in the ncrth, rasting tl/o to t.hreemonths with mean annual rainfall below 8oo nrn, but may last six months in the south, with amean annual rainfall of over 2ooo mm. Temperatures are relatively constanE in the rainyseason' but display substantial variations beEween day anc night in the dry season, when theabsolute maximum and minimum Eemperatures are recorded. The upper basins of the foJ-lowing rivers are locatect in che project area; Gambia, Niger,Senegal. To these must be added the upper reaches of the coastal,i..r.r, in Guinea_Bissau andGuinea' and possibly also in Sierra Leone and Liberia. some of the k-atercourses in the zoneare Permanent, others dry up along all or part of their length ciurir-rg Lhe clry season. JPCI.7 Page 8 3. PROJECT ACTIV]TIES 3.1 D,rta already avaiiable 3.I.1 Entomology (a) Identification and distribution of the vector specie In la/est Afri Simulium damno sum the same geograph ti.no of them, S. d ca onchocer complex. ical distri amnosum s.s ciasis is transmitt Tlt., r,igiri \.lest Afr bution or the same . and S. sirbanumthe savanna form. The zone covered bv the and operationally: One of t.he most important pr distribution of the tr{o species, south so as tc complete the bound subject to the massive reinvasion Moreover, the treatment of this z area in Mali and the fvory. Coast, and S. yahense present report has an advantageous 10cation, both geographically ed exclusively by the species that make up theican species of this complex do not all have vector potency, and'it has now been proved thattransmit the most severe form of onchocerciasi.s, limit of distribution of the vector, which is ctivities is to determine accurately the limit of and S. sirbanum, in the west, south_west and - its northern boundar), corresponds to the knov,zn; in the east, the zone has a corrEnon boundary with OCp. e-campaign a damno sumS aries of a programne which, by definition, should not bes which could be suffered by less welI_protected prograrures. one, the source of reinvasion of the western parts of the OCpwilL be of grear benefit to OCp. rn the present state of our knowledge eight species make up the Simulium damnosum complexinWestAfricaandt1.reirdifferentiationisbasedonchromoso*ulo'ri'ffi*r""- tions ' rdentification is a lengthy business, and the cytotaxonomic method requires breedingfacilities' This explains the comparative scarcity of results in the project area and thelack of accurate information on the distribution of the savanna species and hence on theboundaries that need to be set for the treatment zone. The data which existed prior tLr tlie present project are as follows: In Guinea four species h.tvi, bcen demonstrated: S. sirb soubrense ated with the mountain massifs of a species extremely close to it is important to point out that of a localized population of sanctipauli. a4um, s. damnosum, S , the Iast -named species being clearly associ Fouta Djalon and }Jimba rn Guinea-Bissau no data rvere available bcfore the start of the project place a few specimens of the S. yahense - S In Senegal, morphological examination of biting females has shor^m that it is almostexclusively the savanna species which ate present S. damnos um and S sirbanum at a single squamo sum group were found. d In Mali the same species have been found, together with two other members of the complex S uer en se in orLe placc (Digudra) ancl S. sucjanenseS. sirbanum Although Liberia is not incltrded in the project zone, the species recorded in that country indicate the presenceS. damnosurn S. soubrense and Stogether with S. vahense, fn Sierra Leonc, thc but there were no data on comp I ex . presencc of S. damnosum s.l. has been knovrn for a very long the different species time, of thethe identification and distribution of \ , JPCI. 7 page 9 (b) DistribuE.ion of pre -imaginal sites As with all the blackfly species, the larvae of the species of the S. damnosum c omplex are able to develop only in running water. Since Ehese species, particularly S. damnosum s.s. and S. sirbanum, are extremely demanding as regards Ehe hydrological andfor their loca I ized; precisely. development (speed of current, larval feeding), their breeding as previous campaigns have shown, this makes it possible to ecological conditions places are relaEively catalogue them a The only method Ehat can currently be used for S. damnosum s.1. control is based on thedestruction of the larvae in their breeding places, distribution of these breeding places at all seasons so it is essential Eo know the precise . Studies on the location of the r breeding sites, initially carried out by land or river, are nowadays carried out by air forprojects involving large areas. Reconnaisance by fixed-wing aircraft and helicopter is not only rapid but is the only method providing permanenE access to areas that are ofteninaccessible by 1and. Knowledge available before the damnosum s.1. was as follows: Project started on the distribution of the larval sites of In Gui.nea, the location of the dry-season sites was relatively well knovm for the upperbasin of the Niger (Niger, Tinkisso, I,li1o and their tributaries). Because of the difficurties of access by land, only a fe\./ sEretches of these watercourses had been reconnoitred in the rainy season. For the other basins (Senega1, Gambia, Coliba, Konkour6), sample surveys hadbeen carried out, but no systematic reconnaissance had been undertaken. In Guinea-Bissau, areas of S. damnosum s.1. breeding places were knoum on the riversCorubal (Coliba in Guinea) ".,a celrl-rrt rro general reconnaissance had been carried out. In western Mali, the successive surveys carried out first by land and later by air madeit possible from 1978 onward to catalogue virtually all the larval sites for the complex inthe senegal river basin (Senegal, Fa16m6, Bafing, Bakoye, Baoul6 and their tributaries) in the trdo mai.n seasons . / s Dr r !r I In Senegal, reconnaissance by 1and, and locate and map all the breeding sites of the Gambia and on the Fa16m6, i.e. for the entir in the rainy season by air, made iE possible to S damnosum complex in the upper basin of the e distribution area of this species in the counEry. In Liberia, the distribution of the larval sites has not been systematically studied, butthe series of sites situated on the major \,natercourses have been catalogued. rn sierra Leone, only a few surveys have been performed. (c) Dynamics of the vector pripu laEion and parasite transmission Besides the distribution of the larval complex, it is essential to make a careful s of parasite transmission i-n order to improve campaign. sites of the different species of the S damnosum tudy of the dynamics of ihe vector population and the planning, implementation and evaluation of a A proper understanding of population dynamics cal1spoints: for information on the following - distribution and size of the adult populations; - seasonal variations in the distribution and productivity of the sites; - daily variations; - average age of populations; 't I \ \ JPC1.7 Page 10 - dispersion around the sites, as a function of climatic conditions and the age of the females; - migrations, if any. For other conrnunicable diseases (malaria, arbovirus infections), evaluation of prevalence and incidence provides a rapid indication of fhe efficacy of vector control. With onchocer- ciasis, the reduction in prevalence is too slow for the authorities responsible for vector control to be alerted early enough to any shortcomings in their Ereatments. In order to make a rapid measurement of the degree of efficacy of treatments, it is therefore necessary to introduce strict and continuous surveillance of the vectors between the larviciding campaign and Ehe long-term epidemiological evaluation. Entomological evaluation as practised by OCP meets this objective perfectly. Furthermore, although the purpose of the treatments is to eliminate all vector popula- tions, the true objective of an onchocerciasis control campaign is not eradication but reduction of this parasitic disease to a sufficiently low leve1 so that it no longer represents a public health problem or an obstacle to socioeconomic development. A great deaL of research has been devoted to the study of transmission of the parasite by the vector, and has made it possible to define a precise relationship between the numbers of O. volvulus larvae transmitted at a given place and the severity of the disease in the human populations dwelling in that place. These studies Led to the concept of transmission potential by unit of time (month or year) and to the determinaEion of a threshold (100 larvae per year) below which transmission, if it persists, can be regarded as acceptable. For the rapid and continuous measurement of the impact of treatments on transmission and for predicting subsequent regression in prevalence, it is therefore essential before the campaign starts to study the transmission levels. In these two areas, population dynamics and transmission dynamics, a certain number of preliminary studies have been carried out in some countries of the Project zole. In Guinea, an entomological survey centred mainly on the upper Niger basin has provided satisfactory data on the population dynamics of S. damnosum and S. sirbanum (distribution, dispersion, inean physiological age, seasonal and daily variaEions) and on the levels of transmission. There are no precise data for the basins of the Senegal, the Gambia and Ehe coastal rivers. In Guinea-Bissau, adults have been collected since 1962 in order to determine the Periods for insecticide treatments, but the data do not permit any reliable conclusions to be dravm. In !1a1i, surveys have provided a good knowledge of vector population dynamics on the river Senegal and the lower reaches of its Ewo main tributaries, the Bakoye and the Bafing. Two interesting features should be noted: - the man-biting females are virtually absent during a large part of the dry season; - the zooph ilisrn of the S. damnosum females is very marked on the river Senegal around Kayes, i.e. at Ehe northern limit of distribution of the vectors , 1 t vi 't .l t Levels of transmission was not covered. However, degree of agreement between pictures (hypoendemic along south) . have been studied in the same areas, but a complete annual cycle the results for the rainy season indicate that there is a good the values obtained and the different local epidemiological the northern boundary; mesoendemic and then hyperendemic further f I { a' rJPCl. 7 Page 11 In Senegal data on population dynamics and transmission dynamics are plentiful and of good quality. It has been shown there that the annual variations in populations are synchronous with variations in river f1ow, that the daily biting pattern is characteristic of savanna regions, and that the average age of the man-biting populations results in extremely high proportions of parous females in the vicinity of the larval sites. A single estimate of dispersion was made at Niokolo-Koba. A study of the trophic preferences of S. damnosum s.1. females led to the conclusion that man-biting habits are more marked than in the more northern areas of Mali. The surveys showed that transmission of the parasite could reach an extremely high level. To take an example, the transmission potential at the Niokolo-Koba encampment in the month of August 1971 alone (3OOO larvae, compared wiEh the acceptable threshold of 1OO larvae/year) was identical with the figures recorded in a conventional hyperendemic focus in a whole year. The surveys also revealed a good correlation between the transnission potential in the rainy season and the location of the various endemic zones. In Liberia a continuous survey has been made in some foci of the population and trans- mission dynamics of o volvulus. The quality of the results is excellent. In Sierra Leone, where the vector role of S damnosum was discovered as long ago as L926, no studies have been undertaken since except for one localized survey. 3 .L.2 Epidemiology Onchocerciasis is a chronic disease with a considerable impact on the economy. Its onset is insidious so thaE it is generally diagnosed late and not until complications already exisE. Knowledge of the situaEion can be obtained only by means of systematic surveys. It is a cumulative disease in which each re-infection increases the quantity of O. volvulus filariae and microfilariae, resulting in general disorders, increasingly pronounced cutaneous and subcutaneous lesions, and in some subjects severe eye lesions that may lead to blindness. These last complications are relaEed to the microfilaria counts observed in the villages.In the hyperendemic zone the mean microfilaria count in a village, for all age groups, fray work out at more than 60. It is highest for the 4O-plus age group, which ind.icates the cumulative nature of the disease. Onchocerciasis, which is transmitted by blackfly, is localized in a certai_n number offoci distributed along rivers close to the pre-imaginal sites of s darurosum Prevalence is extremely variable, depending on the dir There are the first-1ine villages, only stance of the villages from the breeding places. a few kilometres arday at the most, where the vectors are very numerous and the number of patients reaches and exceeds the hyperendemic threshold(66% according to the ocP standards), and the second-line villages where prevalence is muchlower (mesoendemic: under 66%; or hypoendemic; under 337.). It will be realized,therefore, that calculation of a prevalence rate for an entire country tras no epidemiological significance; the disease may be very serious in some areas and non-existent elsewhere. rtis therefore important to know the areas in which it is rife and what impect it has ondevelopment. onchocerciasis is regarded as one of the major causes of the underpopulation of certainvalleys, where crop-growing would be rmrch more productive than on the overpopulated plateauxnearby. This situation leads to over-use or incorrect use of land that is of poorei quaritythan the land in the valleys. Moreover, it encourages the departure of the most active members of the population and an undesirable change in the age pyramid of the population.These very severe imbalances have a disruptive effect on the development of the region. rn Ehe senegal basin area the epidemiological situation is somewhat ress well known thanit was in the volta basin area before the start of Ehe ocp campaign. Nevertheless there aresufficient data available to give an impression of the severity of onchocerciasis in mosE ofthe countries concerned. JPCI.7 Page 12 As regards diseases other than onchocerciasis, importance will be reported on. only those of priority public health (a) Onchocerciasis Guinea The first case of onchocerciasis in Guinea was reported by Clapier in 1916. It was not until 1954 that the situation was studied again. Several surveys were carried out from L962to 1978. Most of these surveys were concerned with the situation in Upper Guinea, i.e. in the uPper Niger basin. This zone is well-docrurented and the situation is knovm accurately,parlicularly in the pilot zone Ehat was organized south of Kankan on the banks of the Milo.In the remainder of the country, Middle Gui.nea, Maritime Guinea and Forest Guinea, documenta-tion is much less plentiful and the information is insufficient to indicate the true situation. Al1 the surveys agree that Upper Guinea is a hyperendemic region. Out of 18 634 subjects examined in 1965, 10 3o9 were i.nfected with onchocerciasis, i.e. 55.3% (Table I).As is always the case with this disease, the situation varies greatly from one village to another and even from one region to another. The worst affected region, Dinguiraye, has aprevalence rate of 72.2%. It should be noted that the survey was cenducted on the population aged four years and over. The rate for positive parasitological tests would have been slightly lower if children aged O-4 years had been included. A survey conducted in 1977 confirms that Upper Guinea is the country's most important focus. Out of 538 subjects examined 302 were positive, i.e.56.1% (Table II). Villages visited around Kankan and Kouroussa in 1970 had infection rates varying from 11.3"/. to 92.3%. In one of these vi11ages, Diaragella, examination of children aged O-9 years showed that 24.1% of them were already infected with onchocerciasis. This hyperendemic situation led Dr lhtttgen to devise the index AI5g, defined by the youngest age group in which 5Ct% of subjects are microfilaria carriers. In highly infected villages this may be the 5-9-year age grouP. South of Kankan there is an extremely serious situation with four hyperendemicfoci: Kogb6dou (78.5%), Morigb6dou (73.4%), wami (92.3%) and F6r6dot (7L%). This corresponds to a very high natural infection rate in the blackfly: 22.2% at Hermakonon. The other Parts of Guinea are less affected, but in lliddle Guinea the prevalence rates may stil1 exceed 50% in some villages; in Forest Guinea and Maritime Guinea the rates are much lower (11-33%). To sum up, the different parts of Guinea can be classified as follows Upper Gui.nea : hyperendemic Middle Guinea : mesoendemic a 1 Forest Guinea and Maritime Guinea hypoendemic Research on blindness is very important. Several surveys have been carried out and the number of blind people in Upper Guinea is very high: 186O out of 18 634 subjects, i.e.9.9g%, in one survey, and 111 out of 2078 subjects, L.e.5.34%, in another survey. In the central arrondissement of Kankan there were 148 blind people out of 5884 subjects examined, i.e. 2.5% in a zone that is much less infected than Ehe pilot zone, where 484 people out of 8645 examined were blind (blindness rate of 5.6%) . Several valleys in the upper Niger basin have been abandoned by their inhabitants and it seems that onchocerciasis is one of the reasons for their departure. There are believed to be some 23OO km of watercourses along which the land is fertile, and after elimination of the blackfly this land could be reoccupied by the population. This is of considerable importance for the development of the country. ( JPCl. 7 Page 13 As mentioned above, although the situation in Upper Guinea is well known the situationin Middle Guinea, Ivlaritime Guinea and Forest Guinea is much less well knor"m. Additionalinformation would be needed to define the precise location of the south-western and southernboundary of the control Programne for savanna onchocerciasis. provisionaLly it could befixed along the northern boundary of Maritime Guinea and the northern limit of the forest inForest Guinea. Guinea-Bissau The first case of onchocerciasis was detected by Dr Lecuona in 1956 between the rivercorubal and its tributary the caium. Following this discovery a survey was conducted in1958 along the two main rivers of the country: the corubal and the G6ba, and in 1959 anothersurvey was carried out at Sonaco. In L964-1965 a survey was conducted on the banks of theriver Corubal. ra 1962, 25oo patients were detected. The prevalence rates found at sonaco ranged from53.6% to 67.9%. rnvestigation of the vi11ag.. "hor" a difference between those located inthe GEba river basin, which are in the mesoendemic caEegory, and those located in the Corubalbasin, which are hypoendemic. The number of blind people is comparatively high. The blindness rares vary from o.5%to 4.3%, depending on whether the villages are mesoendemic or hyperendemic. The surveys seem to show that the focus of endemicity is at sonaco and that the level ofinfecEion fa1ls to the north or south of Sonaco. The boundary of the prograrune could be fixed about lOO krn from the mouth of the riverG6ba. rt Passes slightly to the west of Bafata and sonaco and continues to the border withSenegal . MaIi After Lecomte discovered the first cases of onchocerciasis in Mali in 1915, the firstsurvey was made in 1929 by Dr Laigret. IE was followed by a number of others in 1964 atY61iman6, in 1970 in the vicinity of Kayes and Bafoulab6, in 1972 in the 1r,lanantali region, in1975 in the KiEa ""t"lg (Table rrr), in L976 in the Baoul6 loop and in rhe K6ni6ba region(Table rV), atta tGarty in 1978 in western Mali (rable v). Moreover, between L974 and L977seven doctoral theses in medicine dealt with the problems of onchocerciasis. In 1929, 4.5% of males aged L6-25 years were found to have nodules; at Bant6r6dougou42% of the inhabitants had onchocerciasis, and in oEher villages the prevarence ranged from33% to 45%- This initial discovery already showed that in Mali onchocerciasis, diagnosedsimply by the identification of nodule carriers and without exami-ning peopre for parasites, was a serious problem. subsequent surveys have confirmed this. In western Mali onchocerciasis foci are found in all the valleys: Niger, Baou16, Bakoye,Bafing-Senega1, Kolimbin6, papara and Fal6m6. Prevalence is stiIl high. In the Niger valley between Bamako and Koulikoro, 76% of t,^einhabitants have onchocerciasis and 6% are blind; the corresponding figures for the lulandingHills are 56% ar,d 2.2%, for the Faya valley, 56% and 4.7/". in samlko !S-1=, 50 ooo p."praare thought to be infected with onchocerciasj.s. The figures for the Baou16 river endemic or at least mesoendemic region from the river, 6-12 km on average. tributary has become depopulated. are quite similar and this must be regarded as a hyper_ G7.f/" to 7O.3%). The villages are builr a 1o.,g wayIt should be noted that the valley of the Badinn_Ko )t The Bakoye is another hyperendemic zone where prevalence rales vary from 4g.2% to lL.5%.The village of Bagr;j. is very highly infected: 74% onchocerciasis patients and 7% blindpeople. The strip of deserted territory either side of the river is 4-L2 krn wide. JPC1.7 page 14 In the Bafing valley prevalence in the villages ranges from 42.5% to 6T/". Ihe Senegal river is also highly infectedr 22% to 56.4%. The Kolimbin6 is at the upper lirnit of hypoendemic infection, 29.3%, and the Papara is clearly mesoendemic at 52.yL. The Fa16m6, which forms the border between },lali and Senegal, is highly infected: in the K6ni6ba region examination of eight villages revealed prevalence of 62.9%, as high as 79.6% in the village of F6kola. The hyperendemic strip along the river (65.5% to 75.5%) is 4-6 hr wide. A special epidemiological type is found at the northern boundary of this onchocerciasis zorLei the hyperendemic belt along the rivers becomes a narrow strip with prevalence between 60% and 7O%. Human occupation of all these valleys is very low. The blindness rates in all these foci are generally very high. A survey in 77 villages showed rates from 0.3% to LZ.L%, and there were only two villages r^rith no blind persons. In another survey, the blindness rate in one village was 18.3%. The northern boundary of the area affected by onchocerciasis seems to pass through the followi.ng points: junction of the Mali-Mauritania-Senegal borders, north of Y61iman6, Dioumara, and Didi6ni, joining the boundary of the OCP area on the Niger a little to the east of Koulikoro. Senegal It was Tisseuil who discovered onchocerciasis in K6dougou d6partement in 1945. Subsequently a number of surveys were conducted between 1961 and 1978 (Tables VI, VII and VIII) The disease i-s endemic in 40 OOO lcn2 of Senegal: Eastern Senegal and the extreme east of Casamance . It is found along the main rivers of the country. These are the Fa16m6, which for rauch of its course forms the border between Mali and Senegal; the Gambia and two of its tributaries, the Tiokoye and the Diarha; the Doulountou; and the Kayanga. The various surveys carried out mainly concern K6dougou d6partement. In L969 a survey was conducted in 49 villages in three arrondissements Bandafassi, Salemata and Saraya. The total population was 8623; 4247 of. them (49.2%) aged over five years were examined. It was found that 2760 or 64% were infected with onchocerciasis. The rates per village varied from 16.6"/" to 94.6%. This is an area with many hyperendemic viLlages. In 1975, in the course of a survey covering several diseases, eight villages belonging to four arrondissements were examined: Bandafassi, Salemata, Fongolimbi and Saraya. Of 788 subjects examined 388 had onchocerciasis, i.e. 49.LL%. Most of the villages are mesoendemic, and one of them, Djirinn, approaches the hyperendemic level with a prevalence of 63,3%. The survey on Ehe major endemic diseases has extended beyond K6doug ou d6partement and provides data for villages in V6ling ara d6partement as wel1. In the former the endemicity levels are somewhat lower than those previously reported. This is probably because the villages are situated quite a long way from the pre-imaginal sites and because the entire population was examined, including the O-4-year age group which is the least affected by the disease. In V6lingara d6partement it is important to note that Baconto arrondissement has a large number of mesoendemic villages, which indicates that the endemic zone extends further westward. Eye Iesions are plentiful. One survey shows that 14.6% of the population have eye lesions, lO.5% have severe eye lesions and 3% are blind. This is therefore a severe endemic disease which substantially handicaps the developrnent of the country. I i "( Il" JPCl.7 PaSe 15 In view of the indications provided by the surveys, the boundaries of the Project could be fixed as follows: from the border with Guinea-Bissau-(river G6ba) the boundary would pass Other countries Apart from Gambia which has just been mentioned, it would be useful to determine the situation in the other two neighbouring countries, Sierra Leone and Liberia. It has been known that onchocerciasis exists in Sierra Leone since Blacklock detected thefirst case there in L923 at Tombadu, not far from the frontier with Guinea. A number of sur- veys have been carried out Ehere, but the data are still fragmentary. The information obtained by a survey in Liberia in 1975 shows that the whole country is endemic and a large part of it is hyperendemic. rt is only the deep forest that has no oncho-cerciasis Patients. Prevalence would appear to be about 60%, but in ttre majority of cases itis thought not to be savanna onchocerciasis. (b) Diseases other than onchocerciasis The countries within the projected progrartrne area are affected by a large number oftropical diseases, some of which are particularly important. The principal dlseases aremalaria, trypanosomiasis, schistosomiasis and yeLlow fever. Malaria is present in all the countries and is the leading cause of morbidity for all ofthem. Moreover, it causes substantial mortality, 10.8% of deaths in Guinea and 1g ,57. of.deaths in Guinea-Bissau. so far it has not been possible to institute collective preventionmethods. Individual chemoprophylaxis is necessary. south-east of V6lingara to include the whole o east of Gambia where it is probable that oncho conti,nue towards the junction of the frontiers Trvpanosomiasi,s is present in 1975, Guinea-Bissau, where 2foci are being investigated and vector G1o s s ina alis lsp is encountered in the same vaII of its appearance must be lratch be prepared before the onchocer and Senegal thousands of cases are detected each nosed in 1978. The ecological conditions are e.disease, which is particularly frequent in areas again development programnes should take into ac, f Baconto arrondissement across the extreme cerciasis exists, pass north of Tambacounda and of Senegal, l'lauritania and Mali . in three countries: Guinea, where 131 cases were discovered7 cases were discovered in 197g, and Mali, where a number oftreated. As regards Senegal, it should be noted that the resent throughout the south of the country. since the vector eys as the bIackfly, the presence of trypanosomiasis or the risk ed very closely and measures to control sleeping sickness must ciasis-freed valLeys are resettled. tf Schistosomiasis is present in the four coun.tries covered by the project. In Guinea, Maliyear. In Guinea-Bissau 811 cases were diag_ verywhere conducive to the extension of thisirrigated for intensive crop-farming. Here count the severe consequences of this disease. Yellow fever has caused epidemics in each of the countries concerned. rt is not atpresent a current danger, but the endemic zone covers a large part of west Africa and thepotential danger genuinely.exists, particularly in the valleys to be reclaimed. Control ofthis disease is highly effective: it is sufficient to vaccinate the population before theyare introduced into the danger zones. The vaccination is very retiatle and long-lasting. of the other major diseases and conditions, reference should be made to the diseases ofthe respiratory tract, diarrhoea and injuries. These are causes of morbidity that must betaken into account when planning development progranmes for the or.chocerciasis-freed valleys. 3 .1.3 Hydrob io logy rt is inconceivable nowadays to launch a blackfly larvicidal treatment programne withoutcombining it with surveillance of the effects of the iarvicides on the aquatic fauna associatedwith the target blackfly species. rn order to study these effects it is necessary to have the t I l- I JPC1.7 page 16 fullest possible reference data concerning the composition, distribution and seasonal varia- tions of the main fauna that are of economic value (fish) and ecological value (particularly insects). A few localized inventories have been made of ichthyological fauna, but there are noquantitative data for the zone as a whoIe. 3 .1.4 Hydlology In each of the countries covered by the Project there i.s a basic hydrometric network managed and run by the national hydrological services. A consultant has been recruited to review the current status of information on the existing hydrometric installations. In the Niger basin there are 38 hydrometric stations, at 18 of which readings have been taken regularly enough to indicate the monthly flow rates and the modules (mean annuaL flow): six stations on the Niger, five on the Sankarani/Fi6, two on the Milo, two on the Niandarr/Nlafou, and three stations cn the Tinkisso. The number of these stations has been considered suffi- cient for estimating the amounEs of insecticide needed to carry out a larviciding campaign. In the Senegal basin there are 36 hydrometric stations. Mean monthly flows are available for 15 of them. This number could be increased to 22 stations with sufficient water-gauge readings for compiling calibration curves when the data processing undertaken by the Mali hydrology service has been completed. The total readings accumulateo should make it possible to calculate the quantities of insecticide required. In the Gambia basin there are 25 hydrometric stations, 18 of which have sufficient readings for the compilation of calibration curves; 13 of them have calculated daily flows. The den- sity of these stations has been considered adequate for the needs of a control campaign. In the G6ba/Corubal river basin there are 13 stations, four of them in the catchment area of the river G6ba in Senegal, one on the rj-ver Corubal in Guinea-Bissau, and eight in the catchment area of the same river in Guinea. There are seven stations in the catchment area of the Konkour6, three on the Ko1ent6, two on the Mongo and the Kaba, two on the l'lakona and two more on its tributaries. It therefore seems that, while this hydrometric network will need to be supplemented for the implementation of a control campaign against the onchocerciasis vectors, it is already suffi- cient for an estimate to be made of the amounts of insecticide that would need to be provided for the campaign. 3 .1.5 Cartography The existence and acquisition of good maps at different scales (1:1 OOO OOO, 1:5OO OOO, 1:2OO OOO and in some regions possibly 1:50 OOO) are prerequisites for the planning, implemen- tation and evaluation of a campaign of this kind. In Guinea, Senegal and Mali, all the areas are covered by excellent maps at scales of 1:1OOOOOO, 1:5OO OOO and 1:2OO OOO, published by the Institut G6ographique National (IGN) in Paris. There is a map of Guinea-Bissau at a scale of 1:5OO OOO, and recent aerial coverage of the country could lead to the production of new maPS. In Sierra Leone, the avaiLable maps are at scales of 1:50 OOO and 1:1 OOO OOO. 3.1.6 Socio economic aspects Since the ultimate objective of the Project is to reduce the impact of onchocerciasis on the human populations so as to permit the socioeconomic development of the reclaimed areas, i-t is necessary, right from the outset, to assess the contribution of the control prograrmne to t 'l l, I l-- JPCl. 7 page 17 the achievement of the major objectives of the participating countries. The basic approach will be to estimate and compare the benefits and costs associated with the implementation of the Project during the forthcoming periods. The proposed prograrmne should bring benefits in three complementary fields: health benefits; benefits in income as a result of the increased quantity and qualiry of labour and land resources; benefits in distribution, as the populations covered by the progranme are among the poorest in the wor1d. The information at present available for the countries concerned by the Project is inade- quate, insufficient even for a rough assessment of the potential benefits of such a programne. The only information available for any of the participating countries concerns the influence of the prograflrme on the utilization of land resources. Guinea The comparative abandonmenE of some val-leys in Upper Guinea has been attributed to the Presence of the onchocerciasis vector. The area and potential productivity of these under- used zones is not knovm. Guinea-Bissau No information has been collected so far. Western Mali A list of development projects, agricultural and others, has been supplied. of onchocerciasis on the productivity of these investment projects is not known. The influence I ) Eastern Senegal Four develoPment projects, including two resettlemenE programes, are planned in zones of onchocerciasis transmission. The vulnerability of these projects to the disease is not knom. 3 .L.7 Previous campaigns Several campaigns or trials have been carried out in the Project area. In Guinea, insecticide trials were conducted in 1966 in the Faranah and Kouroussa regions(Niger and Mafou rivers). Use of the insecticides (DDT and fenthion) in a concentration of O.O5 mg/litre for 30 rninutes provided effective t'carry" ranging from lO to 6o km. In the same country, a series of treatments was carried out in the upper basin of the Milo in L977. The insecticide used was temephos. This campaign, very localized in space and time, provided no valid entomological or epidemiological results. It was not followed up, In Guinea Bissau, antilarval treatments with DIII were carried out from 1962 unti-l 1979, depending on arrival of insecticide consignments and availability of personnel. Their basic PurPose was to control the nuisance presented by blackfly bites. No useful results for oncho- cerciasis control were achieved. In Mali, experimental treatments are currently being applied in the upper basin of the Bakoye in order to select new insecticides. 3.2 Data obtained by the Pro.iect 3 .2.1 Entomologv (a) Distribution of 1arva1 sites Aerial reconnaissance by helicopter was carried out in Guinea and Guinea-Bissau in April and May 1980. It covered the main watercourses likely to be harbouring the pre-imaginal stages)- JPC1.7 Page 18 of the S. damnosum complex. The upper tributaries and upper reaches of the Niger, the Gambia, the G6ba and the Senegal, the Guinean section of the coastal rivers and their tributaries entering the sea between Guinea-Bissau and Ivory Coast, and the upper reaches of certain tributaries of the Sassandra were investigated. Map No. I indicates the location of the pre- imaginal sites of S. damnosum s.1. in this region during the dry season. It should be noted thaE some rivers !,rere not flowing at the time of reconnaissance (Santa, Kilissi, Lingourou, F6fin6, G€ba, Co1uf6, Cacheu, Gambia, Koulountou, Oundou, Bakoye, Lota, Nianta and Fi6). The Kogon and Tinkisso were flowing only for part of their course. On the other hand, because of early rains, some watercourses no longer had their dry season appearance (Mac6ni, Ouaou, Lofa, Diani, Bafing, Kouya, Milo and Gbanhala). This reconnaissance took 90.4O flying hours, and 25.45 hours were spent collecting samples. (b) Identification of species of the S damnosum complex Although all the samples taken during the aerial reconnaissance in Guinea and Guinea- Bissau could not be identified before this report was prePared, the following results are already available. On the river Lofa in southern Guinea near the Liberian border only S. yahense is found; on the Kaba at the border with Sierra Leone S. damnosum and S. sirbanum are found; on the Mongo at the frontier with Sierra Leone S. yahense and L@ar. found; on the Koumba north of the Fouta Dj alon S . yahense and S . sirbanum are found; in the south on the Konkour6 there are larvae which could belong to S. mengense , but this still has to be confirmed; on the Corubal, S. damnosum and S. sirbanum are found. (c) Population dynamics and transmission The study of the population dynami cs of onchocerciasis vectors and of Onchocerca volvulus transmission was entrusted to the national teams, whose staff had been gi,ven basic or specialist training by OCP and by the Onchocerciasis Research Institute of the OCCGE in Bouak6 (Ivory Coast). The Project provided these teams with the essential vehicles and technical equip- ment, in accordance with the requests submitted. The progranme of work of the teams was drawn up in agreement with the Project leader. In Guinea-Bissau, in order to speed up the work and to teach the methodology to the national team because the Guinea-Bissau staff had not been able to receive the saure training as the other national teams, a consultant mission undertook the work directly. It seems that irr the onchocerciasis zone of the Corubal and C,6ba rivers 7O-8O% of the vectors belong to the SPE cies S. damnosum and S. sirbanum, the savanna vectors. In the dry season the pre-imaginal sites appear to be limited to the two main uratercourses, the river G6ba and its tributary the Corubal. Catches of adults on human bait show that the vector populations are more plentiful along the latter watercourse. The dry season would appear to be the period of fewest bites, however, for biting is then limiEed to the gallery forest. The daily biting Pattern in the dry season is characterized by the two classical peaks between 7 and 10 a.m. and between 5 and 7 p.m. Bel1ec traps made of a sheet of aluminium covered by a sticky substance were used for a preliminary study of the behaviour of gravid and non-gravid females of the vector species. Around certain siEes a certain discrepancy, already observed on previous occasions, between the biting rate and the number of larvae in the site was again noted. This would seem to indicate partial zoophilia of the species concerned. A study of the physiological age of the females caught shows that the overall proportion of parous females is around 51%, wtrich is below the results recorded in the dry season in the bioclimatic zone concerned. Transmission of the parasite is very 1ow on the river Corubal at the end of the dry season; on the river G6ba it is zero. (d) Limit's of the distribution zone of the savanna vectors The very fragmentary results obtained so far on identification of species do not yet make it possible to define the southern boundary of the Project with certainty. However, according to information obtained from Sierra Leone, through the morphological identification of adults of the S. damnosum complex caught in the north of that country, it seems that the savanna area T of Sierra Leone ought to be included in the Project. -t { JPC1.7 Page 19 Following entomological and epidemiological surveys in Guinea-Bissau, it has now been establ-ished that the limit of tidal salt water in the river G6ba, around Bafata, and in its tributary the river Corubal, around Xitole, coincides with the distribution limit of S. damnosum s.1. 3.2.2 Epidemiology An epidemiological survey was conducted in Guinea from 12 May to 1O July 1980. It covered seven administrative regions of Upper and Middle Guinea: Dinguiraye, Tongu6, Mamou, Gaoual, Koundara, Mali and Koubia. In 20 vi1Iagesr 2548 persons altogether were examined out of a total registered population of 3l-39. The national team discovered L223 microfilaria carriers (48%) and 82 blind people. The detailed results show that Middle Guinea is severely affected. Of the 17 villages visited there, four are distinctly hyperendemic: Balabou (8L.52%), Bantala (7O.LL%), Kankouka(84.26%), and Oudaba (69.67%); seven display high meso-endemicity (50-66%), and only three are hypoendemic (2.79-9.52%). Blindness rates are as high as 7.84%. Knowledge of endemic onchocerciasis in the Senegal basin has been improved by a survey performed in Guinea-Bissau in 1980 (Table IX). This showed that the coastal area is hardly affected at all by the disease but that the uPPer courses of the G6ba and Corubal ri.vers are severely affected. Examination of lO22 subjects in the G6ba Valley revealed 354 patients, i.e.34.64% of the population. Seventeen blind people were discovered. In the Corubal Valley examination of 2336 subjects 1ed to the detection of 284 oncho- cerciasis victims, i.e. L2.L6% of the population. There were 13 blind people. In Guinea-Bissau, as in the other countries, prevalence rates are extremely variable from one village to another: in the river C#ba zone they vary from 16.8% to 55.6%; in the river Corubal zone there are four villages with no patients, Si.ntcha Madiu has only O.7% onchocer- ciasis victims, but Cabuca has 55%. On the whole the blindness rate is comparatively Iow, with a maximum of 3.3% at Camquenhi. In Senegal the Project has assembled the data acquired by the Major Endemic Diseases Service from 1978 to 198o. These data confirm the results of the previous surveys. 3.2.3 Hydrobiology In March and April 1980 two hydrobiological missions visited Guinea, Guinea-Bissau and Senegal in order to collect preliminary data on the hydrobiol-ogy of these three countries andto draw up a plan for the aquatic monitoring in the Project zone, for the purposes of an onchocerciasis control progranure using Larvicides. In Mali the knowledge obtained from surveys carried out on behalf of OCP in a tributary of the Senegal river was considered. satis-factory for the time being. The first mission, which was essentially concerned with aquatic invertebrates, visited 12 locations: four on the upper tributaries of the Niger, one on a tributary of the Senega1, one on a tributary of the Konkour6, three on tributaries of the Gambia and three on tributaries of the C€ba. A number of samples were taken at these locations: - qualitative samples obtained by investigation of the different biotopes(brushing of stones, vegetation, etc.); - quantitative samples, using the Surber sampler; - collection of day-Eime drift material; I 'l \ \ t, l\ JPC1.7 Page 20 - collection of night-time drift material; light traps. The second mission was more particularly concerned with the ichthyological populations. Various catchment areas were sampled with the aid of nets. The locations vislted were distri- buted as follows: five in the Gambia basin, three in the C#ba basin, one in the Konkour6, one in the Kolent6, one in the Senegal basin, four in the Niger basi-n, and three in coastal rivers passing through Liberia. I The results of the fication of the species samples taken during these two missions are not yet known, as identi- collected is generally a quite lengthy task. I 3.3 Data sti1l to be obtained - deadlines for obta them 3.3.1 (a) , Entomology Distribution of vectors tInformation on the distribution of the pre-imaginal sites of the vectors in Guinea and Guinea-Bissau during the rainy season is all that remains to be obtained in order to complete the preliminary reconnaissance programne entrusted to the Project. These data will make it possible to calculate the amounts of insecticides to be provided for a campaign, to draw up possible aircraft flight plans, and to determine precisely what the entomological evaluation network will be, and they can also be used to develop the progranure of epidemiological and hydrobiological evaluation. Aerial reconnaissance of the onchocerci-asis zone i-n these two countries has been planned and began in Septenrber 1980. The results of this reconnaissance will be available by the end of the year. (b) Identifiqqliolq e! lLecie! !! tlre S. 4qlqnoslM complex in order to determine the boundaries of the Proiect Identification of samples taken during the first aerial reconnaissance in Guinea and Guinea-Bissau will be completed by the end of the year. Further samples will be taken during the rainy season reconnaissance in the same countries. During this time the national teams will also take samples and send them to the IRO Laboratory in Bouak6, Ivory Coast, for identification. Analysis of the results should make it possible to determi.ne the precise boundaries of the Project by the early months of 1981. (c) Population dynamics and transmission This study, intended to help the evaluation of subsequent control activities, is sEill entrusted to the national teams rdrich should have accumulated sufficient data for an initial evaluation of the situation by the beginning of 1981. (d) Vector susceptibility or resistance to insecticides It has been decided that before any treatment begins the susceptibility of the vectors to the various insecticides that couLd be used for blackfly control should be evaluated in the four countries concerned by the Project. The administrative formalities for carrying out this survey have already been settled. The study should be conducted in November and December 198O, and the report submitted in January 1981. 3.3.2 Ep idemiology (a) Onchocerci.asis The epidemiological data reported in the preceding pages provide adequate knowledge of the onchocerciasis situation in Guinea-Bissau, Mali, Senegal and Upper Guinea. As regards I ft ,l I 1 t rJPCl.7 Page 21 Middle Guinea (I'Iap 2) it should be possible by the start of 1981 to obtain additional informa- tion on endemic onchocerciasis in the following four administrative regions: Tongu6, Lab6, Koubia and L6louma, for which the data are too sparse, These regions are situated orr the eastern slopes of the Fouta Djalon and are crossed by the upper reaches of large rivers:Bafing, T6n6, Gambia, Komba and Kakrima. Particular care should be taken during the surveys conducted for this prevalence study tofind out the exact population concerned so as to obtain data for later use. Investigators should look for parasites by the skin-snip method, establish which eye lesions are present and record the number of blind persons in the total population. An estimate of the number of onchocerciasis victims by region and by country will provide a slightly better understanding of the true impact of onchocerciasis on national development. (b) r diseases The statistics on the other diseases are generally more complete than those on oncho- cerciasis. For the final report additional data on malaria, sleeping sickness and schisto- somiasis and on ye1low fever vaccinations will be collected. 3.3.3 Socioeconomic cts A contract has been signed with the French office for scientific and Technical Research overseas (oRSToM) for the study of the socioeconomic aspects of onchocerciasi.s and its control.The oRSToM investigators involved in this study (an economist, a sociologist and a demographer) will have the following tasks: I to list the development projects onchocerciasis control progranrne, benefit; in progress or planned which could benefit from anindicating the extent to which these projects would - to identify the economic importance of the areas freed from onchocerciasis and madeavailable for agricultural and/or industrial development ; - to study the influence of onchocerciasis on migrations of the population towardsless fertile land remote from the watercourses and the influence of seasonal migrations on the distribution of the disease; - to determine the knowledge of the inhabitants about onchocerciasis and its trans- mission and to estimate the prospects for voluntary participation by theseinhabitants in controlling the disease.\ The report on this socioeconomic survey is due to be submitted in February should highlight the expected benefits of an onchocerciasis control campaign forcountries concerned by the project. 1981. It the four ) 4. ONCHOCERCIASIS CONTROL CAI,,IPAIGN The object of the feasibility study project is to draw up a p1an, with cost estimates,for an onchocerciasis control campaign in the senegal river basin area. without anticipatingthe conclusions of the ocP rndependent connnission or the results of the studies on appropriatetechnologies, the strategy for onchocerciasis control which can be envisaged at this stage ofthe study is the same as that currently applied by ocp. This strategy consists of: - weekly insecticide treatments of all larval sites of S. damnosum s.I. by aircraft; - evaluation of the results of the treatments and their impact on the environment bythe surveillance of the residual vector populations on the one hand and surveillanceof the non-target aquatic fauna on the other; t JPCl.7 Page 22 1 - evaluation of the longer-term effects of the campaign on the incidence of the disease by means of epidemiological surveys; training of technical staff from the countries concerned for the implementation of the progranrne. 4.L Logistic resources 4.L.L Insecticide To be of use in blackfly control an insecticide formulation must have the following characteristics: it must have 1ow toxicity for manurals (LDSO on oral administration to the rat S5OO nC/kil. It must be acEive in a low concentration against blackfly larvae and have 1ow toxicity for the non-target aquatic fauna, both vertebrate and invertebrate. The formula- tion must disperse readily in water, remain in suspension satisfactorily and have good'tcarry" at medium and high rates of f1ow. The entomological and hydrological data available for Senegal and Mali have made it possible to estimate the annual insecticide requirements for an onchocerciasi.s controL campaign in ttrese two countries. This estimate was reached in the following way: For the main rivers and some secondary watercourses, the existing hydrological data proved adequate for determining the concentration and calculating the amount of insecticide to be applied at each treatment point For the other rivers, the study took into account the following items for each water- course or basin: / - List of potential sites - Climatological data - Area of drainage basin - Direction of river flow of S. damnosum s. I - Correlation between the flow of a secondary wat.ercourse and the flow of the main river upstream and downstream from it. A11 these calculations h/ere made on the basis of the characteri-stics of th.e 2C/" emulsifiable concentrate (EC) of temephos which i-s used for blackfly control by OCP. amounts to be applied were determined as follows: /l The - For a flow of O to 19 ^3/sec, 0.3 litres of 20% EC per rn3, which gives a theoreticalconcentration of O.l ng/ liEre for 10 min; - For a flow of 1l to 50 m3f,sec, O.2 concentration of O.066 mgrlIitre for - For a f low greater than 5,o m3f sec, concentration of O.05 mg/Iitre for litres 20%EC p"r 13, which gives a theoretical 1O min; 0.15 litres 20% EC per m3, which gives a EheoreEical lO min. On the basis of the known rrcarryrr of a formulation of this kind (60-7O km in the rainy season, very short in Ehe dry season because of breaks in flow), together with the hydrological and entomological daEa, it was possible t.o determine the number of treatment points. It has been planned to treat the pennanently-flowingrivers throughout the year, while for the temporary rivers, in the light of OCP's experience, treatments are planned from June to December with an extension until February for some rivers. { \JPCL.7 Page 23 The total length of the rivers to be treated in these Ewo counf.ries 1s estimated aE 6660 kn, 2280 lrn of which i-s accounEed for by the main rivers. The amounE of 20% insecticide formulation needed to treat this area is estimated at 138 3OO litres annually, which includes a LC/" allowance for unforeseen purposes. The filling of the Manantali reservoir on the Bafing in Mali could provide an annual saving of 10 OOO litres of insecticide forrmrlation, which would be deducted from the 138 3OO litres mentioned above. River Quant.ity of insecticidefor main river Quantity of insecticide for tributaries Annual total Gambia Fa 16m6 Bafing Bakoye Baou16 Senegal 19 620 L7 L34 20 L36 L2 666 8 287 10 114 6 Ltz 8 390 8 237 4 238 5 734 5 068 25 732 25 524 28 373 L6 9& 14 02L 15 t82 Totals 87 957 37 779 + LC/" L25 736 138 300 As soon as the results of the rainy season aerial reconnaissance in Guinea and Guinea- Bissau are known, Ehe Project will be able to have an estimate made of the insecticide needs for that, zone. It is Eherefore anticipaEed Ehat the insecticide needs for the entire Project zone will be known early in 1981. 4.L.2 InfrasEructure for aerial Ereatments, air operations In the light of a possible carnpaign using aircraft for the larvicidal treatment of rivers, an inventory of aerodromes situaEed in the Project zone and of refuelling facilities was undertaken, Eogether with a survey on air traffic regulations. The following information was collected in each country. (a) Guinea Airports Subject to the precise demarcation of the Project area, there are seven landing strips: - Siguiri: runway 1310 metres long; - Kankan: nrnway 3OOO metres long, of internat.ional standard, used as an inEermediate stop for flights between Conakry and Bamako; - Faranah: ruru^/ay 22OO meEres long, accessible to aircraft of all types and used as an inte::urediate stop for internal journeys to Upper Guinea and Forest Guinea; - Kissidougou: runway 2OOO metres long; - Macenta: ruru.ray 15OO met.res long; - Lab6: enlarged and modernized, is the only airstrip in the Fouta Djalon, 3Ooo-metre runway; JPC1. 7 pa9e 24 Sambailo: runway 18OO metres long Large aircraft can land on these airstrj.ps at all seasons. None of them is more than 34O km away from one of the others. Aircraft fuel (Avgas arrd, nLf j and A1) FueI is distributed by OIIAH (National Hydrocarbons Office), which can transport i.t on request to Lab6 (by lorry) and to Faranah/Kankan (by train). Additional disrriburion poinrs could be negoEiated. Hor^7ever, because stocks ftequently run out, an onchocerciasis conErol campaign should make sure of continuous sources of supply and if necessary acquire barrels for transport. Air traffic Air traffic is subject to the lnternationalregulations in force. Overflight of Grrinean Eerritory by aircraft coming from contiguous countries is allowed, subject to Prior corrmunication of the ftight plans. Landing by such aircraft at airports with no customs facilities could be a1lowed, under exceptional arrangements, for the onchocerciasis operations. Such facilities have not so far been used. (b) Guinea- Bissau Airports Within the Project zone there are secondary landing strips at Bafata, Gabu and Sonaco. Aircraft. fuel There is no distribution network for aircraft fuel in Guinea-Bissau Air traffic This is subject to the international regulaEions in force. For entering the country and for overflight, a request rmrst be made to the authorities with full idenEification of crew members, the characteristics of the aircraft, and the flight plan. No difficulties were encountered in carrying out aerial reconnaissance of the country in a Guinean helicopter. (c) Mali Airports Besides the international airport of lamakofSenou, there are four secondary airstrips in the Project area; one of them is accessible all the year round, whereas the other three are subject Eo seasonal restrictions: Kayes: runway 1165 metres long, 40 metres wide, untarred but usable all Ehe year round; can rake AN 24 and DC3. K6ni6ba: runway 9OO metres long and 28 metres wide, untarred and unusable during the rainy K1EA: season; can take aircraft up to 5.7 tons. runway 8OO metres long,and 3O metres wide, untarred and unusable in the rainy can take aircrafE up to 5.7 tons.season; J it JPCl.7 Page 25 - Bafoulab6: airstrip 9OO metres long and 30 metres wide, untarred and unusable in the rainy season; can take aircraft, up to 5.7 tons. OPerators or pilots wishing to land on these airstrips should inform t,he National Department of Civil Aviation (DNAC) 24 hours in advance. Aircraft fuel Available at Bamako/Senou: Avgas rcOfL3O and Jet e,t/ltt kerosene. Rail rransport essential for Bafoulab6 and Kayes; road transport in the dry season for Kita and K6ni6ba. Air Eraffic Is in accordance with the international regulations in force. For aerial reconnaissance Dl.lAC should be informed, indicating the type of operations , the inte nediate airports , registration number of the aircraft, etc. Reconnaissance already carried out i.n Mali has raised no particular problems with the DMC. (d) Senegal Alrports There are four airstrips in the Project zone: Elro pemanenE ones (Tambacounda and K6dougou); and two temporary airsErips closed from 1O June to 15 September (Simenti and Niokolo Koba). Aircraft fuel JPIfJ and A1 at Dakar and Tambacounda (supplied in barrels from Dakar). There is a barrel factory in Dakar (FUMOA). Air traffic A peruranent overflight and landing permit (airports with or without customs facilities) can be issued on request, subject to compliance with the regulations in force. As soon as all the information on the distribution of the larval sites in the four countries at different seasons has been assembled, the flight plans w111 be drawn up. It will then be possible to indicate the type of aircraft which could be used, the number of machines and flying hours, the Ereatment circuits, the operational bases of the aircraft and the locations of insecticide and fuel depots, and to estimate the cost of aerial treatmenEs. Consultants have already been approached to carry out this study and the results should be known in February 1981. If the insecticide treaEments should be carried out by ai.rr lt is already intended to set uP EIdo bases for the aerial operations, one of which would be located in Guinea because of the large number of vector breeding-places in series in that country. As with OCP, there would be a head of air operations working under the guidance of the head of the vector control unit. He would have tldo operations officers under him, one of whom would be responsible for Grinea. 4.L.3 Road network Road maps are available for each of the four countries covered by the project. There are a few asphalted roads, but the majority of the comrunication routes consist of earth roads or tracks, some of which are not passable all Ehe year round. A good knowledge of the state of the roads i.n each season is essential for planning the logistic support for the aerial operations, the entomological, epi.demi.ological and hydrobiological evaluaEion activlties, and the circuits for installing, calibrating and reading the flow meters. During the 198O rainy I JPC1. 7 Page 26 season the national teams, the teams of consultants and the project staff endeavoured to keept.he fullest possible records of Ehe condition of the road netr^7ork. This information on the densiEy and quality of the road network will also be used forstudying the ProsPects for onchocerciasis vector control by treatment from the ground, wiEhinthe context of the Project activities concerning the study of appropri-ate techologies. A fairly complete evaluation has already been made of the condition of the road neEworkin the onchocerciasis zone of Guinea-Bissau. It shows that apart from 128 km of tarred roadbetween Banbadinea and the Caium bridge, Ehe roads are inabad state and often impassable inthe rainy season. 4.L.4 Hydrometric neEhrork In Ehe light of knowledge about the existing hydrometric network it is possible to draw up a list of projects for monitoring the watercourses in accordance with the needs of theblackfly conErol campaign. These needs are of two kinds: - knowledge of mean river flows so as to assess the amounts of insecticides to be provided; - ad hoc knowledge of the flow rates at the time of treatment so as to apply the correct concenEration. These additional projects will consist either of the setting-up by the national services of new flow measurenent stations, the locations of which are given for infbrur,ation (Map I) , orof the renovation and calibration of sEations that already exist but are badly run. it go"" without saying that the second kind of project is the more urgent. Niger Basin The projects River Niger. to be undertaken are all in the Republic of Guinea in the upper basin of the In the subsidiary basin of the Sankarani, the Gbanhalah before it joins the Kourou-Kelle, The station at Koledougou on the Dion and repaired and recalibrated. two important tributaries have to be moniEored: and the Koulai. the station at Siramana on the Fie need to be Additional calibration wirl be needed on the Milo, and the liazano station on the Baourewill have Eo be put back into service. Flow measurements will need to be made on the water gauges. the Niandan and the Mafou so as to calibrate The Niantan, a small tributary on the left bank of the Niger between Faranah and Kouroussa,will have to be monitored by a ne$/ flow measurement station. The bulk of the work will have to be carried out in the subsidiary basin of the Tinkisso,where the largest onchocerciasis foci are located. Three new staEions are needed to monitor the Lele near to Tassiliman, the Banie atSambaya, and the Bouka-Yro near to Matagania. The stations at Fifa on the Tinkisso and atNiara on Ehe Bouka need renovating. Altogether, six new stations will be needed on the Niger in Guinea, while renovaEions andsupplementary calibration will be required at 15 sEations. I / h r V- JPC1.7 Page 27 Senegal basin In this basin, the lrestern Mali network needs to be supplemented and better supervised. The course of the Bafing is properly monitored, but its three main tributaries, Bale 1, BaLe 2 and Balinn, will each have to be provided with a station. The stations on the upper Bafing in Grinea will need betEer supervision. The subsidiary basin of Ehe Bakoye for whose main tributary, the Baoul6, few data are available, needs to be supplied with: a new station on its upper course in Grinea near to Fidako; a sEation at the end of the Baoul6 loop (Banbaran road), together with the renovation of the Misslra station upstream from the loop; a new sEation on the Badinn-Ko (Moro Moro road), whose course is one whole series of 1arva1 sites. The stations at Diangola on the Bakoye, at Baou16-Gare and at Parc du Baou16 will need calibrating. On the Faleme, a new sEation at Sansande in Senegal would nake it possible, by coryarison with Gourbassi, to esti.mate the contributions of tribuEaries such as the Gandarraka, Kere Koto, Sanoukole and Koila-Kabe, which might need to be provided with flow meters if the rainy season reconnaissance indicates the need for treaEments. The Balinn-Ko, which has not yet been investigated, should be monitored by a staEion near to Fadougou iffinediately uPstream from itsjunction with the Faleme. Gambia basin This basin has adequate hydrometric equipment. However, quite a large number of stations are subject to variatlons in calibration and regular flowmeasurements are sti11 needed to check on any incorrect calibration. Depending on the resul-ts of the reconnaissance, it may be useful to locate a station on the Kounlountou near to Youkoukoun in Guinea and anoEher downstream from Niokolo-Koba near to Simenti. Geba and Corubal basins Depending on the progress of the hydrological studies in Grinea-Bissau, trilo stations will have to be set up on the river C,eba: one at Bafata, donnstream from the main trlbutary, the Colufe, and one at Sonaco, the centre of an act,ive onchocerciasis focus. The river Corubal will be provided lrith another station downstream from the junction with the Fefine or upstream from the rapids i.e. close to Porto-Cabuca. Other rivers The upper reaches of the coastal ri-vers of Guinea have been provided with flow measurement equipment, though additional calibrat,ion work may be required at the nerrer stations pending additional inforrnation on treatment needs. No additional equipment is planned for the rrater- courses in Ehis area. Altogetherr 23 new st,ations will have to be provided, eight in Guinea, nlne in Mali, three in Senegal and three in Guinea-Bissau, and 12 stations will have to be renovated. Since the regions worsE affected by onchocerciasis in the Project zone do not have a viable road neEwork, travel in the rainy season is extremely difficult (particularly in northern Guinea, v/estern MaIi and eastern Senegal). This explains why the flow measurement networks on some major \ratercourses are under-equipped. It should be borne in mind that it w111 not be at all easy to set up the new sEations and carry out the subsequent catibration ,\ r l.r JPC1.7 Page 28 as this will require materi-al resources in excess of those normally available to a hydrologyservice' Efforts must therefore be rnade to obtain external support, particurarly forestablishing practicable access to the stations. It will be advisable noE to scatEer thepoints of activity and to SrouP the logistic resources at operational bases shared by thevarious disciplines that have Eo work in the field. These estimates of the needs for new constructions, given here on a provisional basis, arethe result of surveys conducted by a consultant hydrologist recruited by the project. Theycould be reviewed in the light of the results of the entomologicar surveys being conductedthroughout the 1980 rainy season, particularly in Guinea and Guinea-Bissau. 4.1.5 Radio cormunications An onchocerciasis control campaign operating over an area of 37o ooo km2 needs a systemfor the rapid transmission of information and instructions. If the campaign is based onvector control through larvicides, it is essential that the centres making operationaldecisions are informed in good time of the hydrological and meteorologicar conditions in thezones where the treatment oPerations are to take place. rnformation on the enEomologicalevaluation of insecticide treatments mlst also be passed on quickty to the decision-makingcentres so that the plans of operation can be adjusted if necessary. The sectors and sub-sectors for entomological evaluationr situated close to areas where onchocerciasis is a majorproblem, are generally in isolated localities where development has been seriously delayed,partly on account of the disease. The result is that the conventional means of communicaEi.onsuch as telephone and telex are ofEen rudimentary in Ehe regions where the control progranrneis to be set up. only a radio cormunicat.ions network can cope with this situation andprovide rapid transmission of essential information. The setting-up of a radio cormnrnications network can be considered only Lrith the agreementof the Internat,ional Telecornmunication Union (ITU) and the approval of the national tele_corrmunications services. These national services have a certain number of radio frequenciesallocated to them by rru. They will need to discuss releasing some of these frequencies andassigning them to the onchocerciasis control progr3urme. After that a study will need to beundertaken to verify whether these frequencies can be used by the programne and to check thatthe progranme's broadcasting does not interfere with broadcasting fy Jtter countries that maybe operating on the same frequencies. The project has been in touch with rru and the naEional telecorununications services inorder to obtain agreement in principle on setting up a radio comnunications network. Thisagreement has now been obtained, and Mali has offered to make some frequencies available tothe programre, which shoutd have three frequencies of its own. rt would also be desi-rable,for coordination PurPoses and as a safety measure, for the new progranrne and ocp to have ashared frequency. several firms have been approached to submit estimates equipment. similarly, local companies have been contacted of the generators needed to operate the radio stations. for Ehe supply and insEallation of to obtain estimates for the supply As a very preliminary indication, subject to modifications that may be made when more i.sknown about the Project zone and the needs for entomological evaluation and for operations, theneeds of the programne have been assessed at five fixed radio st,ations of 4oo w, nine fixedstations of 70 W, and six mobile stations of 70 I{; 14 generators would also be required 4.2 4.2.L Eva luation Entomological eva luation Entomological evaluation of the insect.icide treaEment 1arva1 sites of the vectors and by monitoring adult popula of the larval sites provides only local information and isparticularly in the rainy season when the preimaginal site courses in spate. This type of evaluation will therefore s can be carried out by monit ori.ng S tudytions of S. damnosum s.1 not possible al1 the year round, s are located in the middle of r^rater_ be used only as a back-up measure. 4 1 .\ J \ "I JPC1. Page On the other hand, the study of adult populat.ions prior to treatment and later during the treat- ments provides very fu1l information on the influence of the insecticide operations. In the absence of sufficiently effective traps the adult populations are assessed by means of collection on human bait. This is performed continuously throughout the females'period of activity, 1.e. in practice 11 hours a day from sunrise to sunset. The blackfliescollectedarekept in the refrigerator and subsequently dissected in the laboratory or in exceptional cases on the spot. The purpose of the dissections is to assess the age of the blackfly populations present and to assess their parasite count so as to deduce their disease transmission potential. Entomological evaluation is an essential component of any onchocerciasis control campaign because it not only provides information on the efficacy of the insecEicide treatments but also permits rapid implementation of the operational modifications essential for obtaining the best results. As in the case of OCP, where this Eechnique has proved extremely valuable, it is t.herefore planned to seE up an evaluation net$rork in the Senegal river basin which will provide as much infomration as possible so thaE the control operations can be conducted under the best conditions. The evaluation netrrTork will also be responsible for taking readings at the hydro- metric stations and for passing on the hydrological and meteorological data. In Guinea two evaluation sectors are ptanned at Kankan and I"ab6. The subsectors controlled from Kankan will be: Kankan, Bey1a, Kissidougou, Dabola and Siguiri. The sub- sect.ors controlled from Lab6 will be: Lab6, Dinguiraye, llamou, Gaoual and Kindia. In Guinea-Bissau it is planned to establish one sector at Gabu and two subsectors at C,abu and Sonaco. In Mali one sector is plannedatBafoulab6, with five subsectors at Bafoulab6, Kita, Bamako, I(ayes and K6ni6ba. In Senegal there would be one sector at K6dougou and tqro subsectors at K6dougou and Tambacounda. The location of the subsectors could be modified according to the availability of premises or the access roads to the insect collection points or river flow gauges. However, their geographical dist,ribution should remain rm.rch the same. It should be noted that. even at the planning stage the difficulcies of conrnunications and access have made it necessary to plan a greater number of sect,ors and subsecEors than for oCp. Each subsector would be headed by an entomology t.echnician., assisted by a laboratory auxiliary, seven insect collectors, a radio operaEor, a driver/mechanic and Ewo drivers. He would have at his disposal three vehicles, a radio station and the necessary technical equipmentincluding optical equipment. Each sector would be headed by an entomologist, assisted by an assi,stant. entomologist, alaboratory auxiliary, and turo insect collectors. It would have a Bara1e run by a chief mechanic, assisted by rwo driver/mechanics. The entomological evaluation neEarork cannot operate properly withouE good coordination.IE would therefore oPeraEe under the central management of the head of the vector control unit, assisted in this evaluation task by tl^ro entomologists, each responsible for part of the zone. The entomologists would have the following tasks: determining the collection poinEs and the Pattern of collections at each of Ehese points, supervising and analysing the results obtainedby the evaluaEion network, and issuing instructions to Ehose in charge of insecticide treatmenEs. The daily, weekly and monthly results of insect collections should be recorded on speciallydesigned forms so that the data can be fed into the computer for further analysis Surveillance of the susceptibility of the vector larvae to the operational or replacementinsecticides or insecticides on trial would be organized by the entomological evaluation staff. The method used to determine the susceptibiliEy of blackfly larvae to the insecticldes wouldbe that recormended by the WHO Expert Conrnittee on Vector Blology and Control in 19gO. 7 29 , I / r- I t .I, I Ii, I r JPCl. 7 Page 30 In order to obtain strictly comparable results it is desirable that the same person should perform the susceptibiliEy tests throughout the zone. Any accidental or induced reappearance of fhe larval populations would be utilized to reassess the level of susceptibility. 4.2.2 Epidemiological evaluation (a) 0bjective The aim of this evaluation is to provide the prograume with objective data for measuring the effectiveness of the onchocerciasis control activities. (b) MeEhod fhis will consist of examining all subjects undergoing the evaluation for the principal signs of the disease (nodules, skin damage, etc.) and for microfilaria in the dermis (qualitative and quantitative skin snips). A fu11 ophthalmological examination should also be performed !o detect eye lesions and blindness. This evaluation will be carried out in a certain number of control villages, the number of which will have to be determined in the light of the situation in each country. The main criterion is that they should be representative of the situation in the programrne area and should therefore be located in the three endemicity zones - hyperendemic, mesoendemic and hypoendemic - so as to permit an assessmentof the overall situation. As in the OCP area, the evaluation team will visit each village only every two to three years so that it can assess the changes that have occurred in the meantime. To carry out this evaluation properly it will be necessary to establish the demographic situation thoroughly, family by family, and to list by name all individuals included in the evaluation netl^Tork so that each of them can be identified on the occasion of later visits. A sociological study of each of these villages will indicate certai-n special features of onchocerciasis in each one. (c) Epidemio 1 ogy team The team for epidemiological evaluaEion in the field will consist of - 1 epidemiologist - 1 ophthalmologist - I sociologist - 1 recordLng clerkfsecret.ary - 4 nurses able to take and read skin snips - 2 assistants for the ophthalmologist. The team will be supplied with the necessary equipment for performing and reading the skin snips, Eogether \^rith apparatus for ophthalmological examinations. The necessary vehicles and drivers will have to be provided for transporting the personnel. technical equipment, and camping equipment for accormnodation in the villages. 4.2.3 Hydrobiological evaluation An onchocerciasi.s conErol campaign based on Ehe use of insecticides poured directly into E.he rivers will have to include a hydrobiological componeit for monitoring the impact of the larvicides on the non-target aquatic fauna. Specialists in hydrobiology who have taken part in the OCP aquat.ic monitoring programne were asked to sEudy the problems which might arise in the Senegal basin area and to submit proposals for the aquatic monitoring in thi-s area. Their proposals are suflmElrized below. a 1 rl ( I r,'' JPCl.7 Page 31 TI^Io years of hydrobiological observations are needed before the campaign starts so as to obtain a thorough knowledge of the aquatic ecosystems that have to be treated and to obtain sufficient data before t.reatment begins in order Eo demonstrate more readily any marginal effects the larvicide treatments rray have. For Guinea and Guinea-Bissau a team based at Kankan would be responsible for quarterly sampling on the Dion, Milo, Niger, Kayanga and Corubal, six-monthly sampling on the Bafing, and annual sampling on the Koumba, Tomin6 and Konkour6. In Mali, a team based at Bamako or l(ayes would monitor the sites on the Bafing and the Bakoye every Ehree months and an additional site on the Bakoye annually. In Senegal, a team based at Dakar would be responsible for quarterly moniEoring of two sites on the middle Gambia, and would pay six-monthly visits to six sites on the Niokolo Koba, Ehe Ni6r6 Ko, Bakoye, Kayenga, Fa16m6 and Kolountou. The planned sEudies would include chemical monitori.ng of residues and research on the aquatic ecosystems. fhe monitoring procedures will be adapted to the frequency of the visits. Ihey could include sampling of rock fauna using Ehe Surber sampler, and day-time and night-Eine drift samples at the stations visited quarterly. During the six-monthly visits, lt is suggested thaE biotope mapping be carried out; the varlous biotopes could be sampledquantitatively (Ekman grab, Surber sampler) or qualitatively (collection of dead wood, leaves,floaEing naEural substrates, etc.). Each sample collection will be accompanied by a flow measurement. Day-time and night-time drift samples wirl also be taken. Experimental fishing will be carried out with gill-nets, the results being expressed in catches per fishing unit per lOO ,2 p". night. A coefficient of condition (an index based onthe length and weight of the fish) will be calculared. studies cn diet will be conducted by analysing Ehe stomach contenEs. ltre fertility of the fish will also be monitored. It isintended to carry out some fishing by electric-shock methods. A list of the major items of equipment required for the hydrobiology teams has beenprovided. This hydrobiologicaL evaluaEion project proposed by the consultant hydrobiologists willbe revised in the light of the overall cost of the campaign and the possible contributions by national hydrobiology teams under contract to the programe. The needs indicated above aretherefore only a provisional and preliminary estimaEe. 4.2.4 Socioeconomic evaluation Socioeconomic development is theresponsibil-ityof each state. However, the prograffine could play sonre Part in evaluaEing the impact of the onchocerciasis control carnpaign on the economic development projects in progress and on the behaviour of the populations. Suchevaluation is essential for measuring the benefits gained from the contror campaign by eachcountry. At the request of governmenEs the prograrme, through its economic development unit, courdalso assisE with studies on resettlement projects and projects for making the onchocerciasis-freed valleys producEive. The staff of the economic development unit will be limiEed to an economist as unit chiefand a public health adviser, but the unit should be able to call on short-Eerm consurEants ifnecessary. 4.3 Research rn view of OcP's applied research activities on vector and disease contror, the researchcomPonent of the pro8rame in the senegal basin area will be kepE to a strict minirmrm. However, ) I JPC1.7 PaEe 32 research funds will be provided to deal with specific problems of an operational nature which might arise in this zone. For example, such problems might be associated with the specificgeography of some regions of a type not represented in the OCP area (mountainous regions). The prograrune should also conduct special research on possible vector resistance Eo certaininsecticides used locally in agriculture. For the most part, this research woutd be carried ouE by short-term consultants. This does not rule ouE the possibility of conducEing entomological and epidemiological research on onchocerciasis in this zone, using other sources of finance. 4.4 Training The four countries concerned by the project already have a certain number of specialist staff. Guinea - 2 entomologists - 2 physicians - 2 entomology technicians - 2 parasitolory technicians - 1 ophthalmology technician A11 these staff have recently received refresher training in their own fields (entomology, parasitology and ophthalmology of onchocerciasis) . Grinea-Bissau - 2 entomology technicians, trained in medical entomology in Lisbon. Senegal - 1 entomologist, recently given refresher training in hydrobiology - 2 parasixoLogrfentomology technicians. Mali - 1 technician. Sierra Leone There is an entomology service within Lhe Ministry of Health in Freetown. The first two years of the prograrrEne should be devoted parEly to the basic training, installation and in-service training of staff. In a programme operating independently of OCP, the needs for technical staff with special training worrld be as follows: - 9 medical entomologists (master's degree i.n natural sciences, plus diploma of specialist studies in medical entomologY). - 6 hydrobiologists (master's degree in natural sciences, plus special training in hydrobiologY) - 1 ophthalmologist (medical degree plus specialist training) \ I a I t JPCl. 7 Page 33 - 2 epidemiologist/parasitologists (medical degree plus specialisE t,raining) - 5 assistant entomologists (advanced school-leaving certificate ( specialist training) bacca laur6at ), plus 2 epidemiology technicians (advanced school-leaving certificate specialist training) ccalaur6at. ), Plus J 19 entomology technicians (inEermediate school-leaving certificate (BEpC) , plus specialist training) 5 hydrobiology technicians specialist training) (intermediate school-leaving certificate (BEpC), plus - 2 ophthalmology assistants (intermediate school-leaving certificate (BEpC), plus specialist training). The medical entomologists could be recruited from candidates who have received trilo years' training in medical and veterinary entomology within the Abidjan Faculty of Sciences, at the newly created Medical Entomology Training Centre in Bouak6. It might be possible to obtain TDR fellowships for some of these students. After obtaining the diploma in medical and veEeri-nary ent.omolosr the candiates could undertake three months, specialist training in onchocerciasis within OCp. The hydrobiologlsts, also recruited frmr holders of a master's degree in natural sciences, could be given an intensive crash course in hydrobiology, with a choice betrdeen invertebrates and fish. It might be possible to arrange Ehis training at the Institute of EnvironmentalSciences in Dakar. Additional training could be given in a si.x-month period of practical work at the ORSTCII hydrobiolory laboratory in Dakar. After completing their specialist training, the ophthalrnologist and the epidemiologists should be able to undertake three months' pracEical work with OCp to famillarize themselves with the problems of onchocerciasis and with field techniques. The assistanE entomologists and entomology technicians should be given training of six andfour months respectively at the IRO in Bouak6; this could be followed by three months,practical fieldwork with OCp. The epidemiology technicians and ophthalmology assistant.s would be given three months,training at IOIA in Bamako; this could be followed by three monEhs' pracEical fieldwork with ocP. fhe hydrobiology Eechnicians could undergo basic training at the rnter-state FisheriesTraining centre in Bouak6, followed by practical work with the oCp hydrobiology teams engagedin aquatic monitoring. In each country it would be useful Eo train a national physician in general epidemiologyso that he can carry out within his own country the epidemiological surveillance activitiesthat are necessa4r not only for onchocerciasis control, but also for the cont.ror of otherdiseases with public health priority. This training could be given at the WHo centre in Lom6,followed by practical work wirh OCp. National nurses could also be trained at the same WHo centre; they could Eeam up withthe epidemiologist and support him in carrying out the epidemiological surveillance activities. 4.5 Prograrune struc ture In its interim rePort the ocP rndependent Cormrission seems Eo recomend retainingcentralized management for the Prograrme. This reconrmendation may be considered to apply toany other onchocerci.asis conErol progranrne conducted sirm:ltaneously in several countries, wllo might therefore assume the responsibilities of executing agency for the onchocerciasis control Programne in the Senegal river basin area in the same r^ray as for oCp. -l \ ( JPCl.7 Page 34 Iwo different kinds of structure could be envisaged for the new programne, depending on whether it is regarded as independent of OCP or as an extension of OCP. In the former case it, would be necessary to set up a programne management, a vector control uniE, an epiderntology unit, an economic development unit and an administration unit; these structures are virtually the same as those of OCP. The vector control unit would have an entomologist as unit chief, assisted by an enEomologist responsible for evaluation and an expert responsible for air operations. The entomologisE responsible for evaluation would be aided by another entomologist responsible for evaluation in Guinea. In addition there would be five entomologists working in the prograurne sectors. The expert responsible for air operations would be aided by two operations technicians, one of them responsible for Guinea. The epidemiolory unit would consist of an epidemiologist as unit chief, assisted by the epidemiologisE in charge of the evaluation team; the unit would also include an ophthalmologist and a sociologist. The economic development unit would consist of an economisE as unit chief and a public health adviser. The administration uniE would have an admj-nistrative officer as unit chief, assisted by a chief of personnel, chief of finance, chief of equipment and supplies and a chief of garage services ftre technical advisory bodies and the sponsorship and coordination bodies could be cortulon to both prograrrrrres, however. Ttre national onchocerciasis comrittees woul-d of course be separate, excePt in Mali. On the other hand, if the Senegal basin prograllEne were made an extension of OCP, savings would be made on the new rulnagement and on the unit chiefs. However, it would be necessary to strengthen the existing structures of OCP. Care would have to be taken that the efficacy of the technical activities is not impaired by a top-heavy mFnagement s truc ture. If the new prograrnre, like OCP, should perform the larvicide treatments by air, a single contract could be concluded with a single aircraft company. this company would have to supply a larger number of aircraft, but the number of spare aircraft would be smaller and this would probably be reflected in the cost of the contract. the problem of selecting structures for the new Programne should be studied in detail so as to bring out the advantages and drawbacks of the two oPtions and to Present a cost estimate for each. \ t \ 't I , t JPCl. 7 Page 35 5 FINAI{CIAL SII]T]ATION OF TITE PROJECT STAIEMENT OF INCOME AND EXPENDIIT'RE AS AT 31 JULY 1980 (in US dollars) r- / r Income I979 USAID 1980 Belgiurn 300 000 to7 t43 I I Salaries and allowances Travel Temporary staff Sub-contrac t ing Supp 1 ies Progranme support costs 407 t43 Total Unliquidated ob1 igat ions 45 t59 9 250 7 845 4 622 L97 9 49 796 6 97L 1980 73 773 4U2 2 873 95 L54 28 744 L23 4 2 95 28 6 569 M2 873 L54 744 97L I J 56 767 2U 586 26t 353 66 876 26L 353Total expenditure Balance in hand as at 3 I July t45 790 66 876 78 9L4 Unliquidated obligations Balance not obligated Note LINDP is contributing us$ 2oo ooo to the Project rhrough its own projecr nx/ls/ooz/t/ot/14, of wtrich US$ 27 OOO applies ro the year 198O. 6. FINAL REPORT Ttre outline of the final report presented below is intended as a guide. Work now in progress could provide information that will cause it to be modlfied. At the present stage of the study, the mein usefuLness of the outllne is to serve as a basis for discussion and to for:m a framework for classifying the data collected. Ttre report could cmprise the following sections A. Introduction Ttre introduction will describe the history of the Project (requests from governments, meetings, financial support for the preliminary studies, timetable of activities). It will also deal with the health and econornic objectives of the prograrnme. Expenditure JPCl.7 page 36 B. Epidemio of onchocerciasis in the Seneeal river basin area Ttris section will include general info:mation on the disease and the parasite and willdescribe the epidemiology of onchocerci.asis in the Senegal river basin area. rt wiII alsodiscuss the priority to be given to onchocerciasis in comparison with other diseases. (Annex I will detail for each country the knowledge on the epidemiolory of onchocerciasis and other diseases, and will give information on the priority assigned bythe national authorities to onchocerciasis control). C. Vectors Ttris sectLon will describe the savanna vectors of onchocerciasis, their biolory andtheir distribution throughout the zone, drawing extensively on the experience acquired by ocP. (Annex II vill detail for each country the distribution of the breeding sites,indicating the limits of distribution of the savanna vectors, and will present information on population dynamics and transmission). D. Socioeconomic aspects Ihe impact of the disease on the socioeconcmic development of the Senegal river basin area will be identified and the benefits expected fron the control caurpaign will be es tirn: ted. (Annex III will detail for each countr7 the development projects in progress or planned which will benefit from the control operations, the influence of onchocerciasis on the migration of populations, the possibilities of resettlement in the reclaimed areas, and the possible impact of the expected development on the environment). E. Control methods (a) Chemotherapy This part of the report will constitute an updated review of chemotherapeutic methods. (Annex IV will detail for each country the chemotherapeutic measures which might be implemented, taking the existing heal-th structures into account. A costing of such Deasures will also be attempted). (b) Vector control (i) E nv i. r ormentql EAr!4.geqe n! 4rylnod i f ic a t i on Ihis part of the report will point out the environmental m:nagement and modification measures which can be applied in the control of onchocerciasis vectors. (Annex V.1 will detail for each country the environmental rnanagement and modification measures wtrich might be carried out to assist in the control operations). (ii) Control by applica tion of insecticides Larval control. Drawing extensively on OCP experi.ence, this part of the report will list the available insecticides which can be used for controLling onchocerciasis vectors. It will describe the different techniques - ground applications, aerial treatoents, involvement of the population in the control operations - and indicate the needs for supplementing the hydrological networks. \ \ t \ { I (Annex V.2 will give details of the available insecticides). IJPCI.7 Page 37 , Adult control. Ttris part of the report will give infometion on present knowledge about adulticides which might be applied against simuliun and about the strateryfor adulticiding operations. (Annex v.3 will consider the most suitable approach for controlling onchocerciasis vectors in each countr?, should they have to be treated separately). F. Control campaign in the Senega 1 river basin area The whole chapter will refer to OCp experience. (a) Administrative organization This section will Present the administrative organization which is considered suitabl-efor supporting the activities of the control campaign throughout the area. (Annex Vr.1 will present alternatives, with cost estinates). (b) Control operations This section will include a description of the techniques used, details on the treatment circuits, a description of the spraying equlpment, including the aircraft if necessary, and an assessment of the amounts of insecticide. (Annex VI-2 will describe alternative control neasures, with a comparison of the cost of the various alternatives). (c) Eva luation Ttre evaluation of the results obtained in an onchocerciasis control campai.gn includes epidemiological and entornological evaluation. Entmological evaluation. Ttris part of the report will indlcate the methodolory applied, the necessary resources (personnel, equipnent, bases for sectors and subsectors),the dutles of the evaluation teams, and .lnformation on data-processing. Epidemiol ogical eva tion . Ttris part of the report wi applied, the necessary resources (personnel, equipment), the frequency of evaluati.on, and information on data-processi_ng. \ I 11 indicate the methodology list of indicator vi11ages, the (d) Monitorine of vector susceptibility Itris part of the report will present plans for continuous monitoring of the susceptibilityof the vectors to all potential alternative insecticides, including available btological agents. (e) Aquatic monitoring this section will lnclude a description of the recomnended methods, a list of monitoring stations' details of the personnel and equipment required, and indications on data-processing. G. Research Associated research in entomolory and epidemiolory will be described. It will be keptto a minimum to avoid undue duplication of ocp-supported research. H. Training National personnel will be trained at different levels in the various disciplines related to onchocerciasis control in order to provide the programre with the necessary JPC1.7 Page 38 personnel and the participating countries with skilled staff who will be able to continue the control of onchocerciasi,s and other parasitic diseases at national leveI when the programne is completed. I. Management structures The report will present management structures, indicating the responsibilities and lines of conurunication for ensuring the smooth running of the progratrEre; it will also describe the role and composition of the technical advJ-sory bodies. J. Intercountry cooperation Ttris section will suggest means of ensuring close intercountry cooperation. Consideration will be given to the setting-up of national onchocerciasis committees. K. Budget fhe report wilL present the expenditure on personnel, equipment, operations (including cotrrputer time and the cost of technical rreetings), training and associated research. It will take the contributions of participating countries into account. L. Conclusion this section wiLl discuss the justification for a control canpaign in the Senegal river basin area, comparing the expected benefits with the cost of the campaign.' 7. CONCLUSION ltre study of the onchocerciasis situation in the Senegal river basin area has shown that (a) Savanna onchocerciasis is highly endemic in the four countries, for wtrich plentiful data are available in some cases; (b) the vectors of the most severe form of the disease, S. damnosum and S. sirbanum, ( I are Present throughout the savanna zones in these countries; they are not present coastal strip or the forest, and according to the information at present available, virtually absent from the mountain massifs. in the they are If the cycle is not interrupted, transmission of onchocerciasis will continue, its prevalence may increase, and the human, social and economic consequences will- become vrorse Control of this disease could be organized on the basis of the information already available and information which can be obtained in the next few months " ftre programme would (a) have the zones without S. s 1 as its south-western, western and northern boundaries and the OCP area as its eastern boundary; in the south it would cover all potential breeding-places of S. damnosum and S. sirbanum; (b) take action against the disease vectors by spraying larvicides at all the preimagina1 sites of S. damnosum s.1. contained in the zone defined above (c) provide the necessary organizatLon for carrying out all the activities for entomological control, survei1lance, and entomological and epidemiological evaluation until the countries concerned are able to continue these activities themselves r^rithin the limits of their financial resources; (d) cooperate closely with OCP, with wtrich it is geographically, technologically and operationally interdependent. 1 \ ,\ "t 7JPC1.7 Page 39 At the present stage of the study, it is not possible to estinate the contribution that might be requested from the international cormunity in order to carry out a control Prograrme in this region. However, iE can already be stated that the health benefits for the populations affected by the disease would be irmense. Ttre socioeconomic studies to be carried out under the auspices of the Project should provide fairly precise cost/benefit figures for an onchocerciasis control campaign in the Senegal river basin area. 8. DOCTJMENTS CONSULIED Abonnenc, E., Camerlynck, P. & LariviEre, M. (1963) R6sultats d'une enqudte de prospection parasitologique et entomologique dans 1a r6gion du S6n6ga1 Oriental (Itaute Gambie), Bu11. Soc. m6d. Afr. Noire de Ianeue francaise. 8, 322-328 Agoua, H. (1976) L'onchocercose humaine au l'Ia1i. Dipl&ne bibliographique, ORSTOM, 64 pp. R6partition de 1a maladie et du vecteur, Agro, Banon A. (L977) Contribution I l-'6tude 6pid6rniologique de Ia c6citd au Ma1i,(Doctoral thesis in medicine), Bamako, 84 pp. de Araujo, Abreu M. M. M. (1964) Contribuigao para o estudo da oncocercose na Guin6 Portuguesa (Foco do Rio Corubal), Rev. Est. Ger. Univ. de Moearnbique, L, 3-24 de Araujo, Abreu M. M. M. (1965) Contribuigao para o Estudo dos Simuliidae (Diptera: Nematocera) da Guin6 Portuguesa. Estudo realizado na Bacia Hidrografica do Rio Corubal, Bo1. Cult. Guin6 Portuguesa, 20, 35-65 Bassene, A. & Badji, A. (1975-77) Rapport sur 1'fuitenne Onchocercose du Secteur des Grandes End6mies de Tambacounda, Mimeographed documents , unpublished Bassot, J. P. (1966) Etude g6ologique du S€n6ga1 Oriental et de ses confins guin6o-meliens, M6moire BRG{ No. 40 Berl, D., Pendriez, B. & Bernadou, J. (L976) Enqu6te enromologique sur les fleuves Bakoye etBafinq occGE/ ; en R6pub1 IRO No. 6/, ique du Oncho/ 7 Mali, 6, L2 17 noveuibre - 13 d6cembre 1975, PP. Mimeosraphed document 1976, Mimeo- Bernadou, J. & Junod, A. (1976) prospection a6rienne des gites i Simulium damnosum sur leFleuve Gambie et ses fluents (R6 32/ publ 76sraphed document. IRO No. Ttre development of O. volvulus in S. du S6n6gal), 22-27 novembre , 5 pp. Blacklock, D. B. (L926a) Parasit..,20, l-48 Blacklock, D. B. (L9Z6b) The fu Med. Parasir. , e, ZO3-2L1 rther development of O. volvulus sum Th., Ann. trop. Med. in S. damnosum , Ann. troD. Chaperon, P. & Guignen Rapport terminal, , N. (t974) E Colussa, B. (1980) Report on a visit ro unpublished, 17 pp. du bassin continental du Fleuve Gambie. the Republic of Guin6e-Bissau, Mimeographed documen t, Mim'eo aphed Dakar, IrNDP Pro i ect REG.-6O , ], 83 pp. chung' Tung R' D' & colussa, M. B. Rapport de 1a mission sur la situation de ilonchocercoseen Republique de Guinde (mai-juin 1978), Mimeographed document, unpubrished,63 pp. claude, J' (1980) Donn6es hydrologiques necessaires pour une campagne de rutte contre1,onchocercosedans1ar€giondubassinduf1euveS6n6ga1,@, unpublished, 25 pp. Colussa, B. (1980) Report on a visit document, unpublished, 10 pp. ro rhe Republic of Senegal 1z/O/Ao_n/OfAo1, Mimeosraphed JPC1.7 page 40 Colussa, B. (1980) 24 pp. Report on a mission to Sierra Leone, Mimeosraphed document , unpublished, tion A 1a connaissance de la faune du fleuve Sdn6ga1. Poissons du 32, 2lg-221 Dejoux, c. & L6v8que, C. (1980) La surveillance de 1'environnement aquatique dans le cadre de1'extension du programe de lutte contre 1'onchocercose en S€n6-Gambie, Rapport ORSToM,35, 12 pp. Dejoux, C. & Troubat, J. J. (1980) Compte rendu succinct de Ia missfon de prospection hydrobiologique (Entmrologie), Ivtimeographed document, unpublished, 2 pp. De Lauture, H., Pene, P. M6d. Afr. Noire, 3, & Delorme, G. (1963) Quelques aspects de la bioclimatique au s6n6ga1, LO7 -L25 Daget, J. (1960) Conrribu Baoul6 et du Bakoye, De Lestranges, B. (1967) Erabliss K6dougou (S6n6ga1 Orienral), 1. Ifus. nat t. Nat.2" sdrie 1 .\. I t ement d'une carte ethnique des villages du d6partement de Itl6m. Soc. An Paris , 2, lr5-L24 Dembele, Ph. A. (1976) Traitement de masse part la didthylcarbamazine de quatre villages de m6soend6mieonchocerquiennede1ar6giondeBameko),Bamako, 40 pp. Diarra, s. (L974) L'onchocercose au l{"li (o""t"r.l th".i" ir ), Bamako, 52 pp l 1 Frentzel-Beynie, R. (1975) Ihe geographical distribution of Onchocerca volvulus infection in Liberia, Tropenmed Parasit. , 26, 70-87 Ga:ms, R. (1973) quanEitative studies on the transmission of Onchocerca volvulus by Simulium damnosum in the Bong range, Liberia, Tropenmed. Parasit. , 24, 359-372 Garms, R. (1973) Zur Verbreitung von Sinnrlium damnosuE in Liberia, Tropenmed. Parasit.,24, 222-23t Garms, R. (L974) Uber die Verbreitung und Okologie der Kribebelmticken (Simuliidae) in Liberia, Z. Angew. ZooL. , 61, 63-90 Garms, R. (1978) Onchocerciasis in Guinea. Distributions of the vector, parasite and disease, Mimeographed document , unpublished, 8 pp. Faligant, (1966) Recherche Mimeoqraphed document de 1'oncho, occcE/rorA cercose dans 1a va116e de la T6r6ko16, f6vrier 1966, , 2 Pp. T Garms, R. & Post, A. (1966) Field experiments Simulium damnosum larvae in Guinea , West Ga:rrs, R. & Post, A. (L967) Die Simulien der Republik Guinea, West Afrika, Int. Revue. ges. L-36Hydrobiol q, Garms, R. & Post, A. (1967) Die Verbreitung von Simulium damnosum in Guiney'West Afrika, Tropenmed. Parasit. , L7, 443-466 Garrrs, R. & Vajime, C. G. (L975) On the ecology and distribut.ion of the species of the Simulium damno sum complex in different bioclimatic zones of Liberia and Guinea, Tropenmed. Parasit., 26, 375-380 Guillet, P., Pangalet, P. & Grebaut, S. (1976) Prospection des gi tes I Simulium damnosum sur on the effectiveness of DDT and Bqyte',against Africa, Mimeographed document WHO/VBC/66.229 les fleuves Mimeographe e du Mali) , 7-lO septembre 1976, ,5PP. Baou16, Bafing et Bakoye (R6publiqu d document OCCGE/lRO No. 29loncno/t6 JPC1. 7 PaSe 41 Guillet, P., Mondet, B. & Sangare, S. (1978) L'onchocercose dans le Cercle de K6ni6ba(R6publiqrre du Mali). Compte-rendu d'une mission d'6tude sur la transmission onchocerquienne er:la localisation des gttes larvaires des vecteurs le long de la Fal6m6(2 novembre - 6 d6cembre L977), t'timeographed document OccGe/IRO I.Io. 7/oncho/78, 16 pp. Hadija, K. G. (1962) Rapport Guin6e (Nov.d6c. 1962) , relatif i 1'enqu6te sur l'onchocercose dans la RE publique de Mimeographed t arn/oucn/e , 25 PP. la rEgion c6tiEre de Casamance, Bu1l. Soc. m6d. Af r. Noire de langue Hamon, D. J. (1978) Notes sur 1es perspect.ives de contr6le de 1'onchocercose en Guin€e(Conakry), Mimeographed document, unpublished, 7 pp. Hocquet, P., LariviEre, M., Camerlynck, P. & Diallo, S. (1964) Contribution I 1'6tude de la r6partition des filarioses humaines au S6n6ga1. Enqu6tes dans Ia r6gion de Damantan Junod, A. & Bassene, A. (1976) Rapport sur les activitds de 1'Antenne Onchocercose du SecEeur de Tambacounda, Mimeographed document GE/S6n6ga1, 17 pp. Imperato, P. J. & Sow, O. (1971) Senegal river basin, lrop. Incidence of, and beliefs about, onchocerciasis in the geogr. Med. , 4, 385-389 Kass6, Yaya (L977) 190 pp. Onchocercose, cause de c6cit6 en Guin6e (Doctoral thesls in medicine), Kass6 Yaya et Camara, S. Y. (1980) EnquGte sur 1'onchocercose dans le bassln du fleuve (S6n6ga1 Oriental) et franeaise, 9, 398-4O5 S6n6ga1 (R€publique populaire r6volutionnaire de Guin6e). unpublished, 9 pp. Mimeographed docunent l' Kn'rittgen, H. Guinea, J. (197L) Ann. Soc. Remarks on the ep idemiolory and iuportance of onchocerclasis 5L, 6LL-6L4 in Upperbe Ige Med. trop Kn0ttgen, H. J. & Buttner, D. w. (1968) untersuchungen zur EpidemioLogie und Bedeutung derOnchozerkose in Oberguinea, Z. Tropenued. parasit., L9, t_42 Kuzo6, F. A. S.. Rapport d'Evaluation(at/wofool) (1e63 - mai Ls77), du projet de lutte contre 1'onchocercdoctrment. unoublished. ose en Guinde12 pp. Lacan, A. (1963) L'onch ,e au S6n6ga1, I'OCCGE, Patis, 27 1963 Rapport f I 90 Conf. Minist Inter-Etats de Lacan, A. (1965) L'onchocercose oiosLasso t-7 /o4/L9G5, L4o au S6n6ga1, PP. Rapport final 50 Conf. Techn. OCCGE Bobo LariviEre, M., Quere, M. A., Basset, A., Ranque, p., Diallo, S., Basset, M.(L964) Aspect actuel de 1'end€nrie onchocerquienne au S6n6ga1 Oriental,Afr. Noire de langue francaise, 9, 290-295 & Razafinjato, R Bull. Soc. m6d. Lartigue, J. J. & Gr6baut, S. (1 Nioro-du-Sahe1 et Y61iman6, 964) Enqudte s6ro-c1inique polyval t OCCGE,/Centred documen ente dans les r6gions de L7 pp.e Muraz, Le Berre, R. (1966) contriburion l L'6tude biologique et 6cologique deTtreobald, 1903 (Diptera, Simuliidae), M6moire OR.STOM, 17, 2& pp. Le Berre, R. (1972) .Onchocercose et pe t its Simulium damnosuu Le Berre, R. (1971) Projet d'installation d'une antenne oncho.cercose au S6n6ga1, Mimeographed doc.ment occGE/section onchocercose No. zg -"io--r,-r ro. Section e No. 9 la r6gion de l(ayes, Mioeographed 3 pp. I t' 5/ r JPCI. 7 Page 42 Le Berre, R. (1978) Cons6quences de la construction du barrage de Manantal:. (R. Bafing-Bassindu fleuve S6n6ga1-I'la1i) sur 1'onchocercose et 1a lutte contre le vecteur de cette enddmie, Mimeographed doctrment, unpublished PP. Le Berre, R- (1978) Lutte contre 1'onchocercose en Afrique de 1'ouest. Rapport de mission en R6publiques de Guin6e, du Mali et du S6n6ga1, Mimeographed document. unpublished Le Berre, R., Ovazza, M. & Juge, E. (L964) R6sultats d'une canpagne larvicide contreSimulium dannosum theobald (Diptera, Simuliidae) en Afrique de 1.Ouest, proc. 12th Int.Consr. En London. 1964 ,5 t Le Berre, R., Davies, 1'onchocercose: s ocio6conomique, J. B., Walsh, F., Philippon, B. & Garurs, R. (L977) La lutte contre 1' entomologie m6dica1e, un pr6alable indispensable au d6veloppement Symposium Med. Ent. Centenary R. Soc. troo. Med London. 70-75 end6mie onchocerquienne en Guin6e-i3issau, OMS 19gO, 11 pp. Lecuona, M. oliveira (1956) Nota previa sobre a existencia de oncocercose na Guin6Portuguesa (primeiro caso regi-stado), An. rnst. Med. trop., xrrr, g3-g5 Lecuona, M- oliveira (1959) Primeiros dados sobre a disEribuigso da oncocercose na Guin6Portuguesa, An. Inst. Med. trop., &I, 199-2Og Lecuona, M. oliveira (1960) A oncocercose e o seu interesse medico-social na Guin6 portuguesa,Bo1. Cult. da Guin6 Portuguesa, 58, L93-236 Le Du, Dr, Rapport sur 1'6valuation de 1' I Mimeoeraohed document, unpublished. Lev6que, C. & Paury, D. (1980) Rapport de Irlimeographe4 document, unpublished, Ia mission au S6n6ga1, en Guin6e et en Guin6e-Bissau, 3 pp. Lewis, D. S. (1958) Cong. Ent., 3, Simulium damnostrm in the lonkolili va1l ey, Sierra Leone, Epc. l0th Int 541-550 i Lucasse, C. (1965) Rapport sur la visite effectu6e au projet de lutte contre 1'onchocercose in6e (portugaise) 17 pp. I'lasseguin, A., Taillefer-Grimaldi, J. & Leveuf , BulI. m6d. Afr. Noire de langue franqaise, J. J. (1954) Etude g6n6ra1e de 1'onchocercose, 2, l4L-169 dans la province de Gu docurrent, ern/oNcn/s, (23 novembre - 12 d6cembre 1964), l,time Maurin, J. F. & Bassene, A. (f974) 1'arrondissement de Missira, ProblEmes pos6s par le p,rojet de mise en valeur de GE,/TambacoundaMimeoeraphed document Maymard, J. (L974) S6n6ga1; deuxiEme projet de colonis tion de la r6gion des Terres Neuves. Etude de factibilit6, llimeo ed document ORS ka Mondet, B. (1975) Mission d'6tude sur 1' document O}}@..!ld(.]g|QiCrrr] 75, onchocercose au S6n6ga1 Oriental,13 pp. Mimeographed Mondet, B. (1975) Mission d'6tude sur 1'onchocercose au S6n6ga1 Oriental (f6vrier 1975 Centre en sap./ts, tomologiq ue de l'onchocercose OCCGE - ORSTOM, Mime 12 pp. t Onch l'londet, B. & Pendriez, B. (1976) Compte-rendu de mission sur oriental, lllmqogfephed lpqume q lCccE/IRo tto. t4/orrchof 1'onchocercose au S6n6ga1 76, 5 PP. Ndiaye, B. (1970) Groupes ethniques au Ma1i, Editions populaires. Bamako, col-1. Hier. Omar, M. S. (1978) Histochemical differentiation of filarial larvae developing in Simulium damnosum s.1. in OCP area, Mimeographed document, unpublished, 5 pp. 480 pp. a { -tl { Orain, H. L. (L98O) Rapport sur 1'6tude des quantit6s d'insecticide dans 1e cadre du projet interpays d'6tude de faisabilite d'une,caurp,agne de lutte contre 1'onchocercose dans 1a r6gion du bassin du fleuve S6n6ga1 TCP/MPD/OO7, Mimeographed docr:ment, unpublished, 53 PP. Office de 1a Recherche Scientifique et Technique Outre-Mer (L973-L977) Annuaires hydrologiques de la R6publique du S6n6ga1 Ovazza, I'{. (1961) Rapport pr6liminaire sur une mission } K6dougou (R6publique du S6n6ga1). In: proc6s-verba1, r6union du ZfOIA des Chefs de Sections du Centre Muraz, entmologique sur 1'onchocercose a r98/onc:no/7L, 22 JPCl. 7 page 43 .u S6n6ga1 Oriental, PP. \ Mimeographed document 6.10 Pendriez, B. & Sechan, Y. (197 Mimeographed do nt OCC 1) Enqudte GE/Section Onchocercose No. Philippon, B. (L977) Etude de Ia transmission d'Onchocerca volvulus (Leuckart, Simuliidae) 1893) (Nematoda, en AfriqueOnchocercidae) par Siuulium daurosum T:heobald, 1903 (Diptera, tropicale, Trav. Doc. ORSTOM, 63, 3O8 pp. Philippon, B. (1978) Le Foyer d'onchocercoge du Haut Bassin du Fleuve S6n6ga1 en R6publique du Mali. Essai de synthEse. Persoec /o,,.trn/'t g-documen OCCGE-ORSTOM No tlves de lutte antlvectorielle, Mimeographed 83 pp.t2 \. I Philippon, B. (1978) Le foyer d'Onchocercose du S6n6ga1 iental. issances actuelles - Perspectives de lutte, Mimeographed document, No. 1 53 pp. Philippon, B. & Pangalet, P. (L967) Prospection pr6liminaire dee gttes pr6imaginaux de Simulium daurosrrm ftreoba ld, 1903, de la r6glon de Gouina, Rdpublique du I'lali, Rapport final 7" Conf. Techn. OCCGE, 238-244 Philippon, B., S6chan, Y. & Bernadon, J. (1969) I.Iap shoning the dlstribution of Simrliumdaurostrmin!festAfrica(Situat1oninoctober1968),},timeographeddoctrment,@/ 69.73, 5 pp. B., Sdchan, Y., Pendriez, B. & Pangalet, p. (1971) contribution i 1'6tude du d'onchocercose du bassln du fleuve S6n6ga1 en R6 I teg entoEo logiques, Mimeographed docuoent, 1 18 pp. Philippon, B., Le Berre, R., Quillev6r€, D., Brunhes, J., ouedraogo, J. & pangalet, p. (1975)La lutte contre le vecteur de l'onchocercose a l'occcE. R6cultats acquie. Recherches en cours, Rapport final 10"Conf. Techn. OCEAC, Z, 336-342 Phi lippon, foyer , quatre No. 13 Picq, J. J. & Lor6a1, E. Dlauritanie du sud, publlque du Mali. R6sultats de OCCGE,/Section Onchocercos e, (1970) Enqu6te onchocercose rdalisde dans la r6gion de S61ibaby, . L/PARA/7oMimeosraphed document OCCGE/Centre Muraz No Picq, J. J., Lor6al, E. & Jardel, J. P. (L972) L'end6mle onchocerquienne dans la r6gion de K6dougou au S6n6ga1 or.Lental @6publique du,S6n6ga1): un foyer Eypique d'onchocercogede savane, Mimeographed docroent, UHO/Oncho/lZ.SZ, 53 pp. Picq, J. J., Rolland, A. & Richard-Lenoble, D. (L973) L'end6mle onchocerquienne dans les r6gions de Bafoulab6 et de , R6publique du Ua i( d6ceubre 1970), I"limeographed document, O tre Muraz No 1 3 34 pp. Picq, J. J., Roux, J. & Ba, A. (1975) L'end6mie onchocerquienne dans la rdgion de Manantali(R6publlque du Mali), enquOte conjointe Section Parasitologie du Centre Muraz et en Afrique, OCCGE (janvier L97Z),e I Ins ti t/ut Ophtahno logi OCCGE,/Cent,re Muraz No trooicale :.:oTplu.e/t 5, 24 PP. dggrrmgnl. 8 JPCI.7 page 44 Pons, I. & Al6caut (1970) Rapport d'affectati.on au projet de Lutte contre 1'Onchocercose enGuin6e (21 novembre 1967 - 15 septembre 1969), Mimeographed documenrr ern/ot.Iclr/r+ Rev. 126 pp. Prod'Hon, J., Ovazza, L., Simonkovich, E. & Baudoin, C. (1975) L'end6mie onchocerquienne dansle Cercle de Kita (R6publique du l,Iali). Enqu6te de la secrion parasitologie du Centre Muraz, occcE; Novembre 1975, Document rech. occGE No. 6202, L2 pp. Prod'Hon, J., Mongin, C., Bresdin, I., RoL J. F. & Ovazza, L. (1976) L' end6mi e onchocerquienne dans le cercle de K6ni6ba (R6gion de la RiviEre Fa16rn6) (R6publique de Mali) (D6cembre Le76), Document occGE-oRs No.6352. 13 pp. .! .tProd'Hon, J., Ovazza, L., Simonkovich, E. & Baudoin, C. (Lg76) L'end6mie onchocerquienne dansle cercle de Kita (R6publique du Mali) enqu6te de 1a. Section parasitologie du centre Muraz (novenbre L975), ll.imeographed docuoent, OCCCn/Centre Uuraz, no. 57pnfAi6, 10 pp. Prod'Hon, J., Bresditr, I., Roy, J. F. &Ovazza, L. (Lg77) L'end6mie onchocerquienne dans 1aboucle du Baoul6 r(R6Pub1i9ue du },Iali)r ffii 1976, Mimeographed document, OCCGE/Centre uura" rto. z/ptsa/it, 13 pp. Prost, A. (L977) Situation dans un foyer d'onchocercose du Mali aprBs trej-ze ans de contr6le antisimulidien. I. Aspects parasltologiques, Ann. Soc. belge M6d. trop., 57, 569-575 Proat, A., Ihylefors, B. & Pairault, C. (L975) Methods of mass epidemiological evaluarion of onchocerciasis. Iheir utilization in a vector control programe, Mj.meographed document, Oncho "P 5. 14, 21 PP, Qu6r6, M. A., Bassett, A., LariviEre, M., Basset, M., & Razafinjato, R. (1963) Etude statis-tique sur 1a fr6quence et la sp6cificit6 des complications oculaires de 1'onchocercose, Bul 1 Soc m6d Afr Noire 8, L-26 Qu6r6, M. A., Basset, A., LariviEre, M. & Razafinjato, R. (L964) End6mie onchocerquienne au S6n6ga1. AsPects cliniques et 6pid6miologiques des conplications oculaires, Ann. Oculistique, L97, 13O-149 Quil16v6r6, D. (L979) Contribution i 1'6tude des caract6ristiques taxonomiques, bio-6cologiques du complexe Simuliuo damnosum pr6sents en C6te d'Ivoire, Travaux 103, 3O4 pp. Qui116v6r6, D., S6chan, Y. & PendrLez, B. (L977) Etude du comp lexe Simuli-um damnosum en Afrique de 1'Ouest. Tropenmed. Parasit. V. Iden tification morphologique des femelles en C6te d'Ivoire, 28, 244-253 J ,l et vectrices des membres et documents de l'ORST0M, Ridet, J., Enqu6te par sondage Oriental - OMS Equipe IR 5 'onchocercose dans le D6par L2, I'li.meographed document, tement de K6dougou, unpublished, 6 pp. sur 1 r/wr S6n6ga 1 Rolland, A. (1971) Le foyer d'onchocercose du fleuve S6n6gal en R6publique du Mali, rapporr pr6liminaire, Mimeographed doctrment, OCCGEAOTA, Baoako S6chan, Y. (1980) Prospection a6rienne du r6seau hydrographique en Guin€e et en Guin6e-Bissau en saison sBche, Mi.meographed document, OccCr,/22/Oxano/xap/n, 6 pp. Rochette, C. (L974) Le bassin du fleuve S6n6ga1, Monogr. hydrol. ORSTOM, I, 325 pp Simonkovich, E. (L964) Prospection entomologique dans la va116e de la 6ko16 en R6publique du r'rali (3o juin - 13 juiller 1964), Mireographed doct'ment, O Section Onchocercose 6pp Sissoko, D. (L976) L'onchocercose huoaine: mise au point bibliographique, mErites et lacunes ! des programmes actuels de lutte toral thesis in medicine Bamako 58 pp. ,-l JPC 1 PaSe 7 4 5 ). Tendeiro, J. (1963) Estudos sobre Simulios na Guin6 portugueaa, Revista da Junta de Investigagoes do Ultramar, LL, 243-252 Tiern n, Sissoko (L977> Traitement de rrasse par 1a di6thylcarbamazine d'un village d'hyperenddmie onchocerquienne de la r6gion de Bamsko toral thesis in medicine Baroako 33 pp Tisseuil, J. (1945) Troubles de la vue et onchocercose cutan6e au S6n6ga1, exot., 38, 311-312 8u11. Soc. Path \ t T j Toufic, N. (1961) Enqu6te ophtalmologique sur 1'onchocercose dans le Cercle de K6dougou(R6publique du S6n6ga1), 1. sem. IOTA 1, L6-21 Tour6, A. (1976) Manifestations cutan6es de 1'onchocercose Bauako, 48 pp. Traor€, S. & Prud'Hom, J. M. (1980) Epgu6te entomologique sur 1'onchocercose en Guin6e-Bissau, occcE/2lloNcHo/Rap'8o, 23 pp. Doctoral thesis in medici Mimeographed docuoent Trochain, J. (1940) Contribution l 1'6tude de 1a v6g6tation du S6n6ga1, MEn. IFAN I United Nations (L974) Ilydrologlcal and topographical studies in the @mbia river basin. Final rePort, vo1. 3. Howard Ilurphreys & Sons, Engineerlng Coneultants, Ref. 40360 Vajime, C. G. & Dunbar, R. I{. (1975) Chromosotral identification of eight species of the subgenus Edwardselltrm near and includlng Simrlium (Edwardsell trm) darcrostrm Theobald(Diptera: Simrliidae), Tropenmed. Parasit., 26, 111-138 Voelker, J. & C'arns, R. (L972) Zur hydrologie unbekannter Filarienlarven aus dem Onchozerkose- Ubertri4ger Simulium darrosum und aug S. kenyae in Liberia und zur Frage der m6glichen Endwirte, Tropenmed. Parasit., 23, 285-301 I{orld Health Organization (1973) Onchocerciasis controt in the Volta River Basin area, docrrment ocP/73.L, 9o pp.r Geneva tJorld HeaLrh Organization (1976) Epidemiology of onchocerci6sis, WHO Technical Report Series; No. 597 World llealth Organization (1978) Feaslbility of an onchocerclaeis control caqaign in the Senegal river basin area (Republics of Guinea, Mali, Senegal), llimeographed document, wc/78.5, 14 pp. World Health Organization (1978) Perspectives de contr6le de 1'onchocercose en R6publique du S6n6gal-, Mimeographed docr:nent, L2 pp, World Health Organization (1978) Profil de pays. R6publique du MBli, Mloeographed document, Office of the WHO Programe Coordinator, Bsoako, 93 pp. World Health Organizatlon (1979) Intercountry project for the feasibility study of an onchocerciasis control caryaign in the Senegal river basin area (Governnents of Guinea, Gulnea-Bissau, l,tali, Senegal), I,limeographed doctrment, Ii.BC/79.1, 11 pp. World Health Organization (1980) Intercountry project for the feasibility study of, ai , onchocerciasis control caopaign in the Senegal river baein area (Project ICP/MPD/OO7)2 t' t, t Suroary of activities, Mlueographed document, L2 PP JPCl. 7 PaBe 46 * TABLE I. ONCHOCERCIASIS IN GUINEA Results obtained by the H. J. Ihuttgen mission in Upper Guinea (L964-L965) Population over four years of age. The rates are based on the population exanined. IABIfi 1I. ONCHOCERCIASIS IN GUINEA Results of the survey by Dr Yaya Kass6 (1977) I I a T t '\ -{ Region No. of villages Total popula t ion Population .,* exam]-neo Oncho positive Positivity rate (%) Blind people Blindness rate (%) Kouroussa Dabola Dinguiraye Faranah Kankan Siguiri 103 24 t4 10 30 13 53 227 I 487 4 33s 4 399 16 418 5 708 9 673 2 305 L 466 981 2 9t5 L 294 5 091 t 249 1 058 644 1 481 786 52.6 54.2 72.2 65.6 50.8 60.7 986 220 151 67 329 L07 LO.2 9.5 10.3 10.4 11 .3 8.3 Total t94 92 574 L8 634 10 309 55 .3 1 860 9.98 Region Village Totalpopulation Popula- tion examined Oncho positive Positivity rate (%) Eye 1es ions Blind people No Upper Guinea Dabola Faranah I(ankan Kouroussa Siguiri Middle Guinea Dal-aba Gaoual Koundara Mamou Pita Forest Guinea Gneckedon Kissidougou Macenta Lower Guinea Bok€ Dubreka Forecariah Sampolia Sassambo Wami Bankan Koundianakoro Mafaro Bassanto et Buruka-Kour6 Oumpou Tibmo-Dalaba Donhol-Ko16bh6 Tomandou Yarakara Sangassou Lumba-Dyodho Khoria Bintou-I(abaya Fassaliah 1 685 500 115 70 200 800 I 362 400 L25 L25 L25 87 500 1 186 520 166 500 790 80 600 60 50 538 200 96 42 80 L20 627 L72 59 87 L2L 50 138 479 270 99 1ro 434 51 304 39 40 302 90 53 29 60 70 233 47 30 36 34 28 58 162 74 38 50 5t 19 o 16 16 56. I 45 s5 ? 66.6 75 57 .3 37 .2 2L.8 50.8 4L.4 28.L 56 42 33 .8 35.6 38.4 45.5 LL.7 5 37 .2 o 4L.2 40 236 75 31 25 45 60 188 38 23 33 26 26 42 92 44 23 25 30 8 l3 9 78. 1 83 .3 58 .5 100. o 75 85.7 80.7 80.8 76.6 94.4 76.4 92.8 72.4 56 .8 59 60 50 5 5 58.8 42 8t.2 56.2 54 10 10 5 15 L4 4t 2 5 2t 7 J 3 9 6 I 2 7 o o 4 3 Grand total 5 023 2 078 748 36 546 73 111 JPCl.7 Page 47 )- T ). i" TABLE III. ONCHOCERCIASIS IN }IALI: KITA CERCLE Results of the survey by Dr Prod'Hon et a1. (1975) Vil lage Number examined Oncho pos i tive B1 ind people Boubouli Tofassadaga Massala Santakoto Founia-Birgo Founia-Mouribougou Sanko Faraba-Farakou Faraba II Gale Badinko r44 22L 180 101 77 223 3s2 L74 L96 186 424 87 119 80 66 28 105 139 105 t24 155 L54 60.4 53.8 44.4 65. 3 36.4 47 .5 39.s 60.3 63 .3 83.3 36.3 18 8 11 I1 3 8 L2 4 34 4 To ta1 2 278 1 163 51.1 113 TAsLE IV. ONCIIOCERCIASIS IN }1ALI: KERIEBA CERCLE Results obtained by Dr Prod'Hon et al. in eight villages (L976) !i11age Number exa-i ned Oncho positive Blind people Fekola Moussala l.l,adinandi Satadougou Selou Dlahina-Mine Koutila Tabakoto 49 85 113 91 23L 138 225 120 39 55 58 58 r45 99 L29 79 79 .5 64.7 51 .3 63.7 62.7 7 L.7 57 .3 65.8 5 3 4 8 3 TotaI I 052 562 62.9 24 + I JPC1.7 Page 48 TABLE V. ONCTIOCERCIASIS IN MALI Results obtained by B. philippon (f978) / 1 .{ J 1 Region Number ofvil lages Population exmined Onchocerciasis positive Downstream from Kayes Senegal Valley, upstream Papara Valley Other left bank tributaries of the Senegal Lower Koliubin6 Lower Bakoye Middle Bakoye, first series Middle Bakoye, second series Lower Bafing Tributaries of Lower Bafing Bafing, Manantali Bafing upstream from Manantali Tributaries of Middle Bafing Baou16, dorrostrem Baou16 loops Upstream from Baou16 loops Tributaries of Upper Baoul6 Badinnko, upstre@ Middle Fa16rn6 (Senegal) Tributaries of Middle Fa16m€ ( Senegal ) Upper Fa16m6 (Mali) Tributaries of Upper Fa16m6(Mali) 2 8 5 2 3 6 3 6 3 1 6 2 1 2 3 3 I 2 8 2 4 4 57L 968 7L5 3L4 672 1 173 413 L 202 L64 89 L o72 232 4L9 u4 465 552 2% 645 6L2 475 353 680 22.o 48.6 52.9 56.4 29.3 48,2 7L.5 48.4 5L.2 67.O 42.5 42.5 42.5 47 .7 44.7 70.3 59.3 4L.9 75 .5 65.5 69.1 69.6 Total 77 L2 %8 I, JPC1.7 Page 49 TABLE VI ONCHOCERCIASIS IN SENEGAL: SURVEY IN KEDOUGOU DEPARTE,IENT (Rider, L975) TABLE VII. ONCHOCERCIASIS IN SEMC"AL: SI]MMARY OF SURVEYS IN EASIERN SEMGAL (B. Philippon, 1978) \ d Arrondissement Vi I lage Population examined Onchocerciasis positive Blind Per sons Bandafassi Salemata Fongolimbi Saraya Bagnouba Hamdallaye Madina-Boini Dj irine Dimbo Ii Missira-Denti 1a Baitilaye Baraberi 103 103 93 98 93 95 IOl 104 56 45 40 62 4t 46 44 54 54.40 43.70 43.01 63.30 44.Lo 48.40 43.60 51.90 I o 2 1 o 3 1 o 790 388 49.LL 8 Arrondissement Number of vi1 lages visited Population recorded Population examined Onchocerciasis positive % K6dougou colllmrne Bandafassi Fongolirobi Salemata Saraya Missirah Bala 8616 d6p. K6dougou 1 72 36 4s 46 116 55 93 I 5 305 13 200 8 433 6 103 10 349 22 L45 7 543 5 494 L8 2L2 5 492 2 723 790 673 3 20L 462 L LIz L 822 7 583 847 1 389 386 4L.64 15.4 51.01 48.8 4L2 78 s72 L7 475 -! rl d JPCl.7 Page 50 TASLE VIII. ONCI{OCERCIASIS IN SENEGAL Results of the survey by the Major Endemic Diseases Service (1978-1980) I D6partement Arrondissement Vil lages Population examined Onchocerciasis pos i tive Blind Persons 313 253 L46 350 270 279 150 191 L54 L92 111 23 24 15 L26 40 104 83 r42 9L 243 133 82 109 83 L24 316 206 28L 205 69 262 77 IL7 98 93 31 90 2L6 56 28 55 126 L74 189 279 378 243 2s8 l+ 226 549 61 45 31 28 52 24 56 34 27 47 10 4 3 2 15 8 31 7 23 15 L7 24 26 34 2l 33 173 63 50 36 11 63 13 37 13 10 13 51 25 19 4 4 46 48 42 25 19 49 53 o 7 5 19 .5 L7 .8 15.8 8.0 t4.3 8.6 37 .3 17.8 17 .5 24.5 9.O L7 .4 L2.5 13 .3 11.9 20.o 29.8 8.4 L6.2 16. 5 7.O 18 .0 3L.7 3L.2 25.3 26.6 54.7 30.6 17 .8 L7 .6 1s.9 24.O L6.9 31.6 13 .3 10.8 9 7 6 9 3 3 5 6 2 o o 2 5 3.1 o.9 L4. 7" 36. 27. ,, 9. 5. 20. 20. 4t 56 11 33 1 1 o 1 1 o o o 2 1 3 o o o 2 1 o 1 o 2 I 3 1 2 I 3 11 3 3 o o 2 0 1 o o o 5 2 o o 0 2 o o o o 0 o o o o K6dougou Bakel Tambacounda Velingara Bakel Missira Baconto Kounkan6 Bala Saraya Bala Bransan Kayan Galo Brontolon-Fara Gnognoya Bantantinting Guenoto Koular Faraba Gouloumbu Konaoulambey Sare l*lbaye Kirili Sare Nody Sare Dela Dioumou KourenEine Kipi Koufadou Bokolako Timindala Madina Kokoum Kokoun Doulo Fass Tabali Daifa Sam Miss ira-Gounasse Kouba Ainemadi Sounatou Abisia Midona Carrefour Madina- Carrefour Keneba Kapeyel Demba-Niama Alca1y Kankouyama Nonadiyatoul iye Tarsalame Yamane Boussoura Mbal locounda Samaye Akane Tonguia Koundiama Velingara Pakame Sansankoto Kondionte SahaEou Niandonba 8 527 L 557 L8.26 56 ,I. * JPC1.7 Page 517 \. I TASLE IX. ONCHOCERCIASIS IN GUINEA.BISSAU Result.s of the survey by Dr Le Du (1980) f. f. T }t ,'l River basin Villages Population examined Onchocerciasis pos i tive Prevalence (%) Blind Persons Blindness rate (%) Fulamore Sancunda Carantaba Camquenhi Salquenbe Sintcha Samba 190 297 77 225 94 139 85 74 32 114 27 22 t8.3 28.4 39.3 5s.5 27.L 16.8 4 2 I 10 o o Total I o22 354 34.64 L7 Madina lGdinga Benfica Pansor Lenquerim Sintcha Aliu Seide Tchetche Madina 8o6 Cabuca Saltinho Sintcha Sarutal Sintcha l,Iadiu Garti Sintcha Canta Casamanie Sintcha Saido Bambadinca Cassana 230 L27 110 185 L20 L20 134 199 238 200 150 37 58 203 s8 L57 69 31 31 o 2L 18 .9 96 2 o 1 o 1 o 1 4 L.4 o.7 30.8 35.7 22.8 20.7 18 8.7 55 1.3 1.8 2.3 3 o 2 2 1 0 1 4 o o o o o o o o Corubal G6ba Total 2 336 284 L2.L5 13 o.5 1.9 o.6 o.7 3.3 o.7 o.9 o.5 o.6 1.3 t I Ndo6Q!bA ul= o: o . oo B2E!{ra* e i E rP E G(olia i ?u a -l (!l J .> 3 gE Ei E q E 5 ;l E E I H E; l+)IE.E3 ooJo.ot-zUJo.. 'i lJ - ./' / Y\ ($'fo!o- ut rut-=a9 - .)## u , lo a _ ._ . .t..f ' / ')?.I ao J d t/ IJi)=0:oIq,u-2I {il!Ii o F=o o - $oUJ6i, \._l JPC1.7 Page 53 \.Y u UJ E o o t -,- ....... ..: '.t' l\z 5'-UT rQ o o- C) o ) F foY o U )o6 / <. o 5.' oo f oo eiEOuzrl t 'rt' 11' att tt' o2 92 a = /a oJ oY o z zU o o7 vaoNtSS z t E UI a6. = z I o/ G z = ti,lE!g )Z J U)z (D tz,oFUUE L o lu z UJ Ex z o o o G oE' Go E, .9 Eo Eoo .9 =3 o oo |ttg E oz f o(o Fo IIJ -o E, o- (.:, o o =uro a- IJJ lt o o * l, I ( ) Y o Jo Y ) Eo I Fzip;* N \ ) f a 6o' o foo o lu T o E I o J a ro2l oY ..; =(, r r; .+ {I "jr I