Joint meeting of the Scientific and Technical Advisory Committee and Ecological Panel: Ouagadougou, 1- 4 March 1977

oef srrcftt.t ONCHOCERCIASIS CONTROL PROGR.A},IME IN I}IE VOLTA RIVER BASIN AREA SCIENTiFIC A}ID TECHNICAI ADVISORY COMMITTEE Report of the fifth meeting Ouagadougou, 1-4 March 1977 ocPfsrAcfTT.L Page 2 CONTENTS of participants . . Opening of the meeting Election of Chairman Adoption of the agenda List A. B. for L977 the report of the meeting Paragraph 34 40 45 46 49 53 59 63 66 70 71 Page 3 5 6 6 9 9 10 10 11 11 I2 13 13 13 13 D. Insecticides E. Entomological research 22 22 6 6 8 13 F. Medical research (a) Epidemiology (b) Chemotherapy (c) Nodulectomy... Publication of data . . Criteria for the determination of "onchocerciasis-freed" areas Training Trypanosomiasis Schistosomiasis research research Role of STAC Programne of activities Review and adoption of Closure of meeting ocPf srAc/77.1 Page 3 LIST OF PARTICIPA}.IIS Members of the Conmittee Dr E. G. Beausoleil, Director of Medical Servicee, Ministry of Heal-th, P.O. Box N1,44, Accra, Grana Profegsor J. Diallo, Clinique ophtalmoLogique, Universit6 de Dakar, Facult6 de M6decine et de Pharmacie, }@, Senegal Dr Peter Haskell, Director, Centre for Overseas pest Research, @rao" W8 5SJ., United Kingdom of Great Britain and Northern College House, Wrights Lane, Ireland and Control Division, Bureau of Welfare, Atlanta, Georgia 30333, de 1a Recherche Scientifique et 7O-74 route drAulnay, 93140 Bondy, Dr Pieter Janssens, Vogelzanck L2r 2232ts tEqvspru.ezel, Belgitrm Dr II. J. Knuttgen, Director, Instltute of Tropical Medicine, University of Tllbingen, TUbingen, Federal Republic of Germany Dr James Miles, Chief, Pesticides Branch, Vector Biologyltopical Diseases, Department of Itealth, Education and United States of Arnerica Dr Jean Mouchet, Inspecteur g6n6raL de Recherche, Office Technique Outre-Mer, Services scientifiques centraux, France Dr E. L. Rozeboom, School of llygiene and Publ.ic Health, Ttre Johns Hopkins University, 615 NorthlloLfe street, Baltimore, Maryland 2L2o5, united states of Asrerica Ecological Panel Professor H. B. N. Hynes, Department of Blology, University of WaterLoo, Waterloo, Ontario, Canada NzL 3cL Dr R. Smith, Project Director Y&I 73fOLo, c/o UMP, P.o. Box 788, TaLz, yemen Arab Republic Economic Development Advisory Panel Mr I{. de Souza, Development Centre, Organization for Econotnic Cooperation and Development, 94 rue Chardon-Lagache, 75016 parls Cedex, France Secretariat FAO Mr C. G. Gtoom, Senior Officer, policy and planning the Unlted Nations, Vta delle Terme di Caracalla, UNDP dgriculture Organization of Italy Unit, Food and I-O01OO Rome, Mr G. L. Pennacchio, Chief, Division of Regional ProJects, Regional Bureau for Africa,United Nations Development PrograrEne, one United Nations pLaza, New york, N.y. looli, UnitedStatea of America wHo Mr lvtrarc Ls. Bazin, Di.rector, Onchocerciasis Control Programne, B.P. 549, Ouagadougou,Upper Volta Dr J. Hamon, Director, Division of Vector Biology and Control, Geneva, Switzerland ocPfsrucfTt.t Page 4 Dr T. Lepes, Director, Division of Malaria and Other Parasitic Diseases, Geneva, SwitzerLand Dr U. Brinkmann, Parasitologist, Epidemiological Evaluation UniE, Onchocerciasis Control Progranrne, Ouagadougou, Upper Volta Dr J. Davies, Entomologist, Vector Control Unit, Onchocerciasis Control Progranune, Bobo-Dioulasso, Upper Volta Dr B. 0. L. Duke, Chlef, Filarial Infections, Division of Malaria and Other Parasitic Diseases, Geneva, Switzerland Dr R. Le Berre, Scientist/Entomologist, Chief, Vector Control Unit, Onchocerciasis Control Progranrne, Ouagadougou, Upper Volta Mr J. D. M. Marr, Entomologist/fiologist, Onchocerciasis Control Prograurne, Ouagadougou, Upper Volta Dr D. Molyneux, Team Leader, Trypanosomiasis Research Project, Bobo-Dioulasso, Upper Volta Dr A. Prost, Parasitologist, Epidemiological Evaluation Unit, Onchocerciasis Control Prograrrne, Ouagadougou, Upper Volta Dr H. Ramamonjy-Ratrimo, Regional Adviser, Prevention and ConErol of Diseases, Regional Office for Africa, BrazzavLl]-e, Congo Dr J. Raybould, Research Biologist, Vector Control Unit, Onchocerciasis Control Programme, ' Akosombo, Ghana Mr R. C. Sawadogo, Sociologist, Economic Development Unit, Onchocerciasis Control Programme, Ouagadougou, Upper Volta Dr D. Scott, Team Leader, Schistosomiasis Research Project, 1@, Ghana Dr B. Thylefors, Ophthalmologist, Epidemiological- Evaluation Unit, Onchocerciasis Control Prograrmre, Ouagadougou, Upper Volta Dr C. Vajime, Research Cytotaxonomist, Vector Control Unit, Onchocerciasis Control Programme, Tamale, Ghana Mr J. F. trrlalsh, Entomologist, Vector Control- Unit, Onchocerciasis Control Progranrne, Ouagadougou, Upper Volta Dr D. G. Zerbo, Sector Chief, Vector Control Unit, Onchocerciasis Control Progranmre, Tama1e, Ghana ocPfsrMcfTT,L Page 5 A. OPENING OF fiIE MEETING 1. The joint meeting of the Scientific and Technical Advisory Conmittee (SIAC) and the Ecological Panel (EP)I was held in Ouagadougou from 1 to 4 March 1977. Prior to the meeting an informal briefing took place during the afternoon.of Monday, 28 FebruarY, at which the structure and activities of the^Programne were described. Participants also had the opportunity of visiting the AWz development zone at Mogtedo on Tuesday morning, 1 March, and were received by It.E. Ttre President of the Republic of Upper Volta during the afterooon. 2. The meeting was opened by H.E. ftre Minister of Public llealth of Upper Volta, Mr Tlnga Douambarwhoexpressed his Governmentrs appreciation for the holding of the Conuritteers first session in Africa in Upper Volta. the transfer of the resPonsibility for the Prograrune fromWHO headquarters to the WI1O Regional Office for Africa, BrazzavLlle, had beenweLcomed by his Government as being a natural development. Mr Douamba conveyed the concern felt regarding the lack of suitable treatment for the disease and urged the Conmittee to give particular attention to this aspect. Referring to the deveLopment projects which the participatants had viewed that morning, the Minister said that the Government considered the Onchocerciasis Control Prograrmne as being an indispensable first steP toltrards the development of the river valleys. In conclusion the Minister assured the Comnittee of the Governmentrs continuing support for the Progrannre as evidenced by the recent provision of land for the construction of the Progranune Headquarters. 3. Mr Bazin, Director of the Prograrme, rreleoned the participants and discussed the role and function of the Scientific and Iechnical Advisory Corunittee, ParLicularly in relation to the research progragne. Mr Bazin indicated that he expected more input from the Cormittee in future and would like it to be more responsive to practical problems of the Prograrmre. He felt that STAC should concentrate on a fel problems on lshich specific guidance was required raEher than attempting to review all Programre activities in general terms at each meeting. For example: . (a) Would it be acceptable to replace Abate before resistance develops by an alterna- tive insect.icide which, in trials, rras observed to have a more drastic effecE on non-target organisms in treated than in untreated riversi orr should larvicides be changed every t\ro years to prevent the build-up of resistance to any one larvicide? (b) Can STAC recormend alternatives should resistance to organoPhosphorus compounds, particul"arly Abate, develoP? (c) Is there an algernative to the present system of entomological evaluation based on control of breeding sites and captures of female flies? (d) What al"ternative methods can be recomended to determine early or light infections in a population? 4. Mr Bazin made it clear that he did not, of course, exPect irmrediate answers but that these were the type of problems on which OCP would Like to receive the guidance of STAC. 5. Mr Bazin reminded the Cormnittee that the terms of reference of the Corunittee required an annual report which should be presented to the Joint Coordinating Co'unittee (.lCC). Previousl-y, no annual report had been submitted. 1 o ,"n"..te report has been PaneL and its reconmendations to issued covering those matters of concern to the Ecological the Steering Cormnittee. 2 Autorit6 des Amenagements des Va116es des Volta. ocPf sr^cf77.L Page 6 B. ELECMON OT CI1AIRMAN 6. Dr P. Janssens was elected Chairman of the meeting. appointed Rapporteurs. C. ADOPTION OF TI{E AGENDA 7. Ihe provisional agenda (Annex I) was adopted" D. INSECTICIDES Dr J. Miles and Dr J. Mouchet were 8. The selection of insecticides and the development of suitable formulations for Simulium control were reviewed. The Cournittee r^ras particularly pleased with the plans fo. tffig- ch1-orphoxim emulsifiable concentrate, a microencapsulated form of chlorpyrifos methyl, and several- other compounds in the spring of L977. It considered the trough method developed at Bouak6 particularly suitable for the comparative testing of differenE formulati-ons and dosages under similar conditions. 9. Ihe Conrnittee was informed that the field test of chLorphoxim to be carried ouL on the Nzi Ln L977 should indicate whether this insecticide could be considered as a potentially suitable replacement for Abate. Chlorphoxim, being inErinsically a simpler compound to synthesize, should be cheaper than Abate but being also an organophosphorous compound, its utilization as an alternative cannot be taken for granted should resistance to Abate develop. The Committee urged that emphasis be given to the development of other insecticides, especially in particu- late and microencapsulated formul-ations, which coul-d be more selective in killing Simulium larvae and which could be int,roduced with assurance in the event of such development of resistance. 10. Ihe Conrmittee was concerned to hear that resistance to DDT had been found in S. damnosum larvae in rivers both within and outside the Prograrune area where DDT had not previously been utilized for Simulium control. As this is apparently the result of DDT used for agricultural spraying being washed into the river, the Conrnittee urged that an inventory be made of all agricultural pesticides used in the area. Such resistance precLuded the introduction of chlorinated hydrocarbons such as methoxychlor, and the new biodegradable DDT analogues. 11. With regard to the proposed caution in view of their possible being rather more susceptible than trial-s with insect gror^rth regulators the Conmrittee urged effects on other stream fauna, Ephemeroptera in particular Simulium. 12. The Cormnittee approved the periodic interruption of treatment at certain siEes in order to obtain sufficient larvae for susceptibility testing. It also considered that for these tests it might be appropriate to use larvae reared fro,nr eggs obtained from wild-caught blood- fed females. E. ENTOMOLOGICA]. RESEARCH 13. The Conrnittee, presented with a comprehensive review of all the entomological research activities, noted with satisfaction the progress made by the smal1 number of personnel invol-ved. The cooperation of the Ghana Goverrunent in providing laboratory facilities at Akosombo for rearing S. damnosum was acknowledged as being of great assistance to the Progranrne. Ihe entomological research being undertaken was well planned and the Corrnittee reconunended that the work continue on the laboratory rearing of S. damnosurn (nr -f. Raybould); the taxonomy of the species of the S. damnosum complex (Or O. Qui116v6r6 and Dr C. Vajime); the development of suitable trapping devices (Or C. Be1lec); and on the behaviour and distribution of the adults in connexion with the reinvasion phenomenon (Dr R. Garms). 14. Ttre Conurittee, noting that some savanoa speci-es of the S. damnosum complex were found in forest areas, and Ehat some forest species appeared in isolated locations in the savanna zone, considered that work by Dr Qui116v6r6 on the establishment of the link between the different species of the S. daurnosum complex in relation to their ecologicaL requirements should be intens ified. ocYf srrcftt.t page 7 15. the Conunittee expressed interest in the finding of hybrids of some of the species and, while the state of the chromosomes indicated that the flies would be unlikely to survive, fel-t that attempts should be made to observe the further development of the larvae from sites where such hybrids are particularly cormron. 16. The Conrnittee appreciated the value of the report on the Species Cornplexes in InsecE Vectors of Disease and recomnended that particular ernrphasis be given to studies on the field identification of all stages of the species of the S. damnosum complex (pr S. V. Petersen and Dr D. QuilL6v6r6). STAC also felt it was important for the study of the seasonal distribution of the different species of the complex to be conpleted in the rivers imrediately outside the Progranrure area in order to identify possible sources of reinvasion from Ehose rivers which, for technical reasons, should be considered for inclusion in any extensi.on of operations. L7. The Comnittee expressed concern at the limited nr:mber of cytotaxonomj-sts abl-e to identify the different species of the complex and considered hovr further specialists could be trained. In the meanEime those availabl-e, especially the Prograurne cytotaxonomist, r,rere requested Eo assist entomologists in participating countries by identifying larvae sent to them. 18. the Co,rurittee endorsed the preparations for the L977 research on reinvasion. While supporting the establishment of additional meteorological stations, SIAC considered that more attention should be patd to recording wind speeds at high altitudes rather than at units of two to three metres above Ehe ground as at present. 19. The Conrnittee urged a certain caution in the interpretation of the results from source identification by the X-ray fluorescent spectroscopy technique being carried out by Mr R. Bennett. It was felt that negative resulEs were fairl-y reliable but there was a possibility of feeding behaviour interfering with the interpretation of resul-ts. However, XFS was recognlzed as a potentially useful tool and Ehe Conurittee agreed that its further use shouLd depend on a detail-ed evaluation of the computer print-outs. 20. The Conrrittee recorirmended that a SAP working group on population modelling be convened in 1978. 2I, The Cormittee vtas inpressed with the mass of information on the S. damnosun complex accnmulated by the Prograrme, which probably represented 90% of all t"iif.afr" Ehe west Afrlcan species of this complex, but was most concerned at how few of these data and results had been written up. It strongly reconrmended that action be taken urgently to have all this material published (see Section G). F. MEDICAI RESEARCH 22. Ttre Committee rsas informed of the rnedical research activities carried out in 1976. (a) Epidemiology 23. Ihe work being undertaken on the amount of transmission of O. volvulus Ehat is associated rtith different l"evel-s of ocular onchocerciasis within the Prograr-re area and in the savanna areas of northern Cameroon was considered to be highly relevant to one of the main problems now facing the Progranrne, namely the determination of tolerable levels of onchocerciasis and the maximum permissible level of O. volvulus transmission compatible with resettlement of those Parts of the controlled area previously deserted on account of river blindness. STAC noted that the team working on onchocerciasis in the United Republic of Cameroonr i.€. Dr J. Anderson and Dr H. Fuglsang from the Medical Research Council, London, United Kingdom, and Mr A. Renz from the University of Tllbingen, rtas making a valuabLe contribution to the knowledge of various asPects of the disease, incl-uding epidemlology and chemotherapy. STAC strongly recomrnended, therefore, that this team receive long-term support to conti.nue its research work. The data collected by Dr J. Anderson, Dr H. Fuglsang and Mr A. Renz should be collated and analysed as soon as possible in conjunction with Dr R. Dietz of lllbingen University, who is constructing a predictive mathematical model of onchocerciasis transmission. ocPf srAcftT.t Page 8 24. Ihe Cormnittee also recognized that valuabLe information concerning transmission l-evels i.s being amassed by the Prograrune in areas under vector control. Ihe work of Dr U. Brinkmann, Prograrmne parasitologist, in collecting a series of colour slides deplcting a wlde variety of skin lesions was cortrnended, as well as the associated histological study of biopsies from these lesions carried out at the University of Rome. STAC considered that every attempt should be made to improve and standardize the system of classifying and recording the skin lesions of onchocerciasis in field surveys, and coll-ections of coloured photographic material could be an invaluable and indispensable means of disseminating this information. 25. It ldas noted that Dr M. Denk6 and Dr 0. Bain had begun studies on the distribution of animal Onchocerca spp. in the Prograrmne area. Preliminary reports indicate that infections are preval-ent in cattle and are also found in wild ungulates. Investigations into the development of animal Onchocerca in species of the S. damnosum corrplex, and a study of the morphology of any infective larvae developing therein, were considered to be of great importance in relation to Annual Transmission Potentials in the Prograuune area. 26. A number of more basic studies on parasitology, such as: (i) the possible distinction between strains of O. volvulus by means of enzyme staining; (ii) the in vitro culture of microfilariae of 0. volvulus; (iii) the isolation, purification and identification of O. volvulus antigens; and (iv) the search for animaL models for onchocerci.asis, rdere considered to be projects more suited to support by the WI{O Special Progrannne for Research and Training in Tropical Diseases, with assistance from OCP in the collection of material. 27. Ir autoPsy USAFIP. was suggested that OCP should cooperate with other Divisions of WHO in obtaining material from persons dying whil-e infected rlrith O. volvulus for Dr D. A. Connor of 28. The epidemiological importance of the discovery by OCP staff Ehat some babies born to mothers heavily infected with O. volvulus show positive skin snips was again emphasized. It was considered Lhat further studies should be done on the frequency of the phenomenon, the exact mechanism of the transfer of microfilariae, and the survival of the microfilariae in the skin of the baby. Knowledge of all these aspects wou1d be of importance in assessing the significance of O. volvulus-positive children as i.ndicators of continuing transmission after control is established. 29. In order to define levels of onchocerciasis that can be accepted for areas in which the Annual Transmission Potential of the vector has dropped bel-ow a certain level, studies will be undertaken by the Epidemiological Evaluation Unit (EPI) to compare the prevalence of severe ocular onchocerciasis for areas with known Annual Transmission Potentials. 30. Examinations for microfilaria, canthus snips, head nodules and the number of micro- fiLarlae in the anterior segment of the eye w111 be used to determine risk factors for severe onchocerciasis. 31. With the data accumulated during the baseline evaLuations, the epidemioLogy of skin l-esions, visual impairment and onchocercomata will be studied. Ihe correlation between onchocerciasis prevalence, microfilarial density, severe ocular onchocerciasis and blindness will be investigated. The geographical distribution of onchocerciasis and blindness will be further investigated. 32. TreatmenE triaLs rrith diethyJ-carbamazine, levamisole and metrifonate will be carried out in cooperation with the Centre Nhtraz in Bobo-Dioulasso, or, in vil-Lages near Ouagadougou, by the staff of. O1PfEPI alone. 33. The necessity of obtaining, as soon as possible, the services of a second ophthal.mologist with adequate training and experience in African ocular onchocerciasis to assist Dr B. Ihylefors rras again emphasized as essential to the execution of the epidemiologicaL and chemotherapeutic work of the EPI Unit. ocPfsrAcfTT.L Page 9 (b) Chemotherapy 34. ltre Couunittee took note with approval of the chemotherapeutic trials planned and in progress as foLlors: (i) levamisole and DEC alone and in combinatlon, at OCCGE, Bobo-Dioulasso (Dr Prodfhon and Dr Morault); (ii) low-total dose courses of suraoin, around Bamako (Mali) (Dr Rougemont); (iii) metrifonate, DEC and suramin (with reference to clinical pharmacology and toxicity) at Tamale, Ghana (Dr Awadze and the team from the Liverpool School of Tropical Medicine). 35. The Comuittee emphasized the importance of adequate ophthalmoLogical surveiLlance in all these trials. It also noted that no triaL had previously been carried out in the area where transmission had been almost elimlnated, and that the results obtained on aging populations of rrorms might be different and, perhaps, more successful, than those previously obtained under normal conditions of reinfection. 36. Itre Cornmittee noted with satisfaction the results of Dr J. Anderson and Dr H. Fuglsang in Cameroon which indicate that a microfilarial load above 10 mf/ng in a skin snip taken from the outer canthus of the eye is a reliable and simple indicator of a high risk of severe ocular onchocerciasis and bl-indness. It was felt that this was a sirpLe practical method that could be used in survey work by unqualified personneL to detect patients at speciaL risk of blindness and hence in need of treatment. 37. Ihe trial.s of metrifonate (trichlorophon) carried out in Cameroon by Dr Anderson and Dr Fuglsang were also noted with interest. ltrree doses of 1O ng/ke metrifonate at intervals of two weeks were sufficiently mild in their microfilaricidal action to be acceptable to virtually all patlente, even the most heavily infected, without the need for steroid cover, Ttris dosage scheduLe reduced the microfilarial concentrations in the skin to about 30% of their pretreat[ent leve]. and had a similar action (also without serious side effects) on microfiLariae in the eye. 38. In view of the present paucity of satisfactory methods of large-scale treatment, lhe Cmtrittee considered that a carefully supervised triaL of these Eechniques for diagnosls and treatment should be prepared and carried out by the EPI Unit in a village or villages in the OCP area, using the outer canthus snip as a risk indication and treating with metrifonate those at speciaL risk. If the results were favourabLe, such methods might be appLicable Later on a Larger scale by national treatment teams. 39. Itre Corunittee noted with approval the research supported by the WIiO Special Prograrune, to promote lead-directed synthesie and screening of new co,ryounds for filaricidal action, and the attetrpts to involve the pharmaceutical industry in the development of filaricides. It also rroted that attempts rrould be made to investigate for possible fiLaricidal action a variety of drugs already approved for hunan use. Both these more basic aspects of chemotherapeutic research were felt to fa11 within the domain of the IIIIO Special Prograrme. It was agreed that OCP research should be concentrated upon clinical and field trials with knoqm filaricides. (c) Nodulectomy 40. The Cormittee noted with approvaL that the nodulectony triaL undertaken by Dr W. Buttner and his team (Tropeninstitut, Hamburg) had been successfulLy carried out and that a thorough ophthalmological examination of the treated patients (many of whom were rtat riskrr of blindness) had been made by Dr B. Thylefors. This would permit an assessment Eo be made of the possible beneficial effects of total nodulectomy as a means of delaying or preventing the onset of b lindness. ocPfsr^cf77 .t Page 10 4L. The important breakthrough made by Dr BUttner and Dr Schulz-Key in successfully extracting the adult O. volvulus rdorms (d and 9) from nodules treated with collagenase was also recorded. This method permits a thorough evaluation of the state of the adult lrorms. The Cormnittee considered that it would be valuable to examine the state of the worms in representative groups of nodules excised at intervals of: saYr every Ewo years, after trans- mission is controlled. 42. The Cormnittee drew attention to the opportunities in the fields of aniulal models and in vitro culture, which could be exploited (especially by the Special Prograrmre) as a result of the collagenase digestion method. 43, Finally, note was taken of the preliminary results of the trial of head nodulectorny carried out in Cameroon by Dr Anderson and Dr Fuglsang which show the method to be of very limited value as a means of preventing severe ocular onchocerciasis j.n Africa. 44. Although head nodulectqry appears to be of limited value in changing the course of the disease in areas where transmission is uninterrupEed, removal of all detecEable nodules may have a different value in preventing or delaying the onset of blindness when it is carried out on patients living in areas under controL. However, in view of the costly and time-consuming naLure of such an exercise, the Committee recormended against the initiation of a Seneral prograrnme of nodulectomy, even though such a prografime could have considerable psychological value to the population, until a proper assessment is made of the trial now in Progress. G. PUBLICATION OF DATA 45. The Conrnittee agreed that it rilas essenLial to secure the publication of all information and data deriving from the Progranrne for the benefit of other organizations, and countries with an onchocerciasis problem. lWo levels of publication were required, the first and most important being scientific papers in international journal.s, the second being basic information on the progress and results of the Progranrne for general use. It was recognized that sclentific papers could only be prepared by professional staff members who were at PresenE precluded from writing up their findings because of the pressure of oPerational work. It was recorEnended that WIIQ explore within its rules and regulations the means whereby personnel may be given the opportunity to wriLe up their results. H. CRITERIA FOR TI{E DETERMINATTON OF ''ONSIIOCERCIASIS.FREED'I AREAS 46. Following the request of the Joint Coordinating Corrurittee (.fCC) for criteria for the determination of |tonchocerciasis-freedtr areas, STAC reviewed PaPers PrePared on the subject. Ihe Connrittee cautioned against a misinterpretation of the Eerm rtonchocerciasis-freedrr stressing that transmission would be reduced to a 1eve1 which would permit resettlement, but the maintenance of the situation was dependent on continued vector controL oPeraEions and any cessation of such activities woutd inevitably Lead to a return to intoLerabLe conditions. An extensive discussion took place in which members expressed the view that it was necessary to define the tolerable level of onchocerciasis as well as the parasitological parameters and the amount of transmi.sslon associated therewith. The Committee felt that the quantitative transmission of infection expressed as an Annual Transmission Potential (ATP) was a considerable advance but urged caution in determining a criEical 1evel; all data avaiLable on this subject should be reviewed. In vlew of its complexity the CoumitEee recormended that a working grouP should meet to review the subject and prepare a report for consideration at its next meeting. 47 " The Conrnittee recognized the importance of establishing criEeria for "onchocerci.asis- freedt' areas in view of the fact that donor goverffnents are reluctant to provide additional financing for resettlement prograrmnes until they are assured that Persons moving into Ehese areas are not at risk from onchocerciasis. 48. The entomologists explained that since the corunencement of operations, the rainy seasons had been such that rivers under control had not reached very high 1eve1s. In order to test their ability to maintain successful control under all conditions, and to assess the efficacy of preseint techniques under these conditions, VCU would need to carry out control in an exceptionally wet year. 49. and owf srrcftt.r page 11 I. TMINING TLre Conrnittee discussed the short- and long-term training requirements of the Programre noted the following points: (a) Some of the highly-skilled personnel involved in the Programme would leave in the not too distant future and would have to be replaced by other experienced and cornpetent personneL, preferably 1oeal1y recruited. (b) People with the requisite knowledge and skills are becoming increasingly difficult to find, and in some cases few exist either in the African Region in general or the participating countries in particular. (c) It is imperative that the national" health authorities of the participati.ng countries shoul.d start developing and strengthening their capacity to take over the staffing of the Programne. (d) As regards other parasitic and vector-borne disease probtems in the onchocerciasis area, a review revealed a virtual absence of personnel skilled in their control throughout the region. 50. Ttre Cotmrittee agreed that these observations emphasized the importance of developing a training prograrElle for adequate numbers of nationals both for onchocerciasis control activities and also for other parasitic and vector-borne diseases, and made the following recorunendations : (a) that these facts be brought directly to the attention of the C,overnments of the participating countries by aLL possible channeLs; (b) that the Governments concerned be urged to give serious attention to the develop- ment in their odn countries of suitable organizations for onchocerciasis control inparticular and other parasitic and vector-borne diseases in general; (c) that these, as wel-l as previous STAC recornnendations on the subject (Report of fourth STAC meeting, paras. f06-11O), be brought to the attention of the JCC at its next sesslon. 51. The Co'rmittee felt that training should cover three broad requirements: (i) trainlng to produce control ; (ii) training to produce partlcipating countries, senior personnel versed in general principles of vector personnel particularly relevant to OCP requirements in such as ophthalmologists, ento,mologists, epideruiologists ; (iii) training of technical personnel to meet OCP requirements and to provide back-up services in participating countries. 52. Arrangements should be made to introduce the scientific and medical (especially ophthaLmological) asPects of the Progranrne to university students in participating countriesto stimulate interest in the study of the disease and the operations to combat it. J. 18.]PA}IOSOMIASIS RESEARCH 53. At its previous meeting the Cormnitteers attention had been drawn by the representative of the Ecological Panel to the problems related to resettlementr. in particular exposure to other diseasee such as schistosomiasis and trypanosomiasis (OCp/SfeC/10.2 Rev.1, paras. 102-LO3). In line with WIIOTs proposal at that meeting the team leaders of the research projects concerned with these diseases in the area had been lnvited to report to the Conunittee on the problem" ocPfsrAcfTT .L Page 12 54. Dr D. Molyneux of the IIHO Project IJ.fWOfOZt entitled "Applied Research on Trypanosomia- sis Epidemiology and Control: Trypanosomiasis Surveillance and Glossina Control in the Moist Savanna Zonett explained the various component parts of the WffO/flWOp p."L:ect which were medical, entomological and training. The medical prograrmre, al-though handicapped by the absence of a medical officer, was involved in surveys and in the evaluation of serodiagnostic procedures; it would later undertake clinical and chemotherapeutic studies. The entomologlcal component was fu11y operational and was presently working on the development of techniques for the ultra-1ow-volr:me appl-ication, from a helicopEer, of insecticides suitable for use against riverine Glossina and acceptable environmentally. Ihe training component of this project had not yet giGG r.y. 55. trrlith regard to trypanosomiasis in the OCP area it was pointed out that depopulation of the river valleys during the early part of this century could, in certai,n instances, have been attributable to this disease. Large Glossina populations (riverine as well as savanna species) hrere to be found and detailed information on species distribution rdas available. At the same time f:-gures for sleeping sickness in the Programe countries did not reflect the true situation and it was well-known that residual foci existed. 56. lligrant labour hras recognized as the major factor in the dissemination of the di-sease, and the setElement zones of the Prograrune area would attract many people who had been in contact with endemic foci. 57. The actions required to remove the dangers of epidemic sleeping sickness were listed as follows: (a) Provision of an adeguate diagnostic service, if possible specifically for sleeping sickness criteria in settled areas, with a reliable link with good treatment facilities and the maintenance of surveillance into residual foci within the OCP area. (b) The introduction of suitable vector control technology using the most environ- mentally acceptable insecticides. (c) While recognizing the danger of drug resistance, consideraLion should be given to protecting the population at risk through the administration of pentamidou as a chemoprophylac tic . 58. The Conunittee rsas aLso informed of the problems which wouLd be encountered in raising non-trypanotolerant cattle in these regions during the development of a balanced rural economy. Veterinary Public Health Services should be alerted to these dangers in view of the exj.stence of animal trypanosomes in G. morsitans and in game animals of the river va11-eys. K. SCHISTOSOMIASIS RESEARCH 59" Dr David Scott, Project Manager of the I,II{O Project MPD-028 entitledrrResearch on the epidemiology and methodology of control of Schistosomiasis in man-made lakest' reviewed some of the problems 1ike1y to be encountered in the settlement of populations in the cleared river val1eys. Taking north Ghana as an example he informed the Corunittee that information available showed that area to be endemic for urinary schistosomiasis, S. haematobium, which was very widely distributed, whereas S. mansoni was confj.ned to on1-y three foci in this area. Some seasons were more dangerous than others. 60. In any resettlement, whether this be spontaneous or controlled, water is required. It is recouunended, therefore, that wherever possible the position and type of watering faciLities be planned in advance. The digging of wells to provide Idater for domestic consumption is essential- and the creation of circumstances that would permit the spread of the disease should be avoided. Dams shouLd be situated at some distance from villages and fenced, if possible. Past experience has shown a tremendous gap between the epidemiologist and the planning engineers and it is imperative that they get together in the initial stages of development to avoid situations which would increase the danger of disease. ocPfsr^cf77.L Page 13 61. IL may be possibl-e to contain the situation by the use of molluscicides but it is preferabLe that preventive steps be taken prior to the establishment of new settlements. Ttris particularly refers to areas lrith localized S. mansoni infection in which extensive prevenEive measures should be taken in order to avoid its spread. 62, The Co'mnittee expressed appreci-ation at receiving this information regarding trlpanosorriasis and schistosomiasis and, while it is not rrithin its terms of reference to deaL with matters outside the Onchocerciasis Control Prograrme, it considered it to be its duty to bring to the notice of the Joint Coordinating Cormrittee the added risks to which people will be exposed when resettled in these cleared river va11eys. If action is not taken ahead of time, the economic development of these valleys would certainly encounter difficul ties. L. ROLE OF STAC 63. In considering proposals made by the Prograrnme Director the STAC members agreed that the time was opportune to redefine the role of the Conrmittee in relation to the Prograrrne. Because of the difficulty of dealing in depth with the numerous technical aspects of the Prograrrne it was suggested that more use be made of SAP working groups; these would make a critical review of specific scientific topics and report to subsequent STAC meetings. In this way STAC would be abLe to devote fulL attention to major problems arising in the Prograurne and play a more decisive role in evaluating and developing the policies of the Progranrne. It rras felt that to handle these matters properly, future meetings should be of at least one weekrs duration. The Cormrittee urged that all working documents and research reports be provided well ahead of the date of each meeting to ensure adequate consideration by members. 64, In view of the diversity of technical problems that might be met in carrying out the Prograrmne, the Connuittee felt that the OrganizaEion should consult members of SAP more frequently through correspondence and views received shoul-d be corununicated to STAC. 65, The Conunittee considered a proposal that its terms of reference should be changed to al-low it to convene once a year instead of twice and agreed that this should be discussed at the next meeting. M. PROGRAMIM OF ACTIVITIES FOR 1977 66, The Corunittee agreed that a SAP Working Group to deEermine the level of transmission which would permit the economie development of the area shouLd be convened in Geneva in late June or early Ju1y. 67. With regard to a SAP trIorking Group on insecticides to consider the questions raised by the Prograrme Director, it was felt desirable to wait until spring 1978 when results of the current series of trials would be available. 68. The Cornnittee was informed that the Annual Report of STAC r^ras Eo be submitted Eo i,rrHO by 10 August 1977. 69. It was proposed that the next meeting of STAC be held in Brazzaville in October on dates to be agreed with the Regional Director. N. REVIEW A\ID ADOPION OF TIiE REPORT 70. Ttre Conrnittee reviewed and adopted the present report. O. CLOSURE OF MEETING 7L" In closing the meeting, the Chairman expressed his appreciation to the Government of Upper Volta for its generous hospitality and to the Prograrune Director and secretariat for thefacilities and assistance provided to the Coruuittee.