Report of ecological panel

JOINT COORDINATING COMMITTEE Onchocerciasis Control Programms in the Volta River Basin Area Ofice of the Independent Chairman c/o World Health Organization l2ll Gencva 27, Switzcrland Tcr. 34 6o 6l rctcx lilllr 27 82L J.C.C..C.C.C. COMITE CONJOINT DE COORDINATION Programme de Lutte Contre l'Onchocercose dans la R6gion du Bassin de la Volta Bureau du PrCsident Indlpendant c/o Organisation Mondiale dc la Sant6 l2ll Gendve 27, Suisse T.l 3'+5061 T6lcx lllEf, 2782L JCC6.4 22 October 1979 JOINT COORDINATING COMMITTEE S ixth sess i.on Geneva, 3-5 December 1979 Provisional agenda item 6 The Independent Chairman submj.ts for the consideration of the Joint Coordinating Committee, at its sixth session, the report of the Ecologlcal Panel which has been reviewed by the Steerj-ng Committee. B3 REPORT OF I'IIE ECOINGICAL PAI.IEL ONCHOCERCIASIS CONTROL PROGRAMME IN THE VOLTA RIVER BASIN AREA A. OPENING OF THE SESSION 1. The nlnth session of the Panel was held ln Joule HalI, Universlty of Salford, from 27 to 28 Septembet L979. Ttre meeting followed lrnrnedlately uPon that of the hydroblologist teams with the Salford Universlty team whlch was ln the process of assembling and analysing the aquatic monitorlng data generated by OCP fleld operations. 2. The meeting was held under the Chairmanshlp of Professor Dr J.H. Koeman, who opened it with a welcome to members of the Panel, lndependent consultants and technical officers of OCP and the Sponsoring Agencies. AMPTION OF TI{E AGENDA Ttre following Agenda was adopted: 1. Opening of the session 2, Adoption of the Agenda 3. Progress of OCP vector conErol operattons 4. Hydrobiologlcal moniEoring - data collecEion, processlng and analysis (i) report of the Hydrobiologists' meeting (ii) processing and analysis of data 5. lnsecticides - larvicldes - Abate - Chlorphoxim - Other candidate larvicides - adulticides 6. Future scale of monitorlng and related sEructures 7 , Other matters - VeEerinary asPects of resettlement - IUCN Resolution No. 5, L978 - Future OCP structures - lndependent OCP Conmission 8. AdopEion of the Report 9. Close of the Meeting. 2C. PROGRESS OF OCP VECTOR CONTROL OPERATIONS 4. The Panel was informed that vector control operations had been continued throughout the OCP area including the extension area in southern Ivory CoasE. The control to the west of the line of the Rlver Oti was very satlsfactory with the annual transmission potential and annual biting rate generally meeting the criteria adopEed Ln L977. At the height of the wet season 18 OOO km of river were being treated each week diminishing to about 4 OOO km in the dry season. It had been possible to stop treatment on several sEretches of the Black and Wtrite Volta, in Upper Volta, between October 1978 and l(ay L979 wlthout any bulld-up in blackfly populatlons. Detailed studles in central Togo and Benin had shor,rn that this area was belng relnvaded by S.damnosum although penetration of the controlled area may be more limited than it was in the southwest. 5. It was noted with satisfactlon that in areas reaching the prescribed entomological criteria, epidemiologlcal studles had provided no indication of disease transmlssion. The Panel shared Ehe view of the Sclentific and Technical Advisory Comnitt€e Ehat OCP should noE be complacent about the apparent success as the environmenLal and climatlc conditions in 1979 could have been unusually favourable. 6. Riverine Woodlands The Panel recognized that Ehe success of the Progranme could soon lead to an increase in the development of the river valleys. Concern was expressed that, with the movement of the population back into these riverine areas, there was the real danger of the forest gallery alongside the water courses being removed to make more land available for cultivation. The Panel drew attention to the disastrous ecological effect this could have particularly on soil erosion, water flow, nutrient status of the rivers, water temperatures (affecting Ehe breeding conditions of some economic fish species) and the leaching of soil nutrients. The Panel, recalling what had happened in many parts of Africa with the destruction of riverlne woodland, strongly reconrnended that wide and diverse forest galleries be retained on each side of T^rater- courses. 7. Ttre Panel recognized that the forest gallery harboured disease vectors such as tsetse, as well as predators and felt this aspect urgenEly required investigation. D. HYDROBIOLOGICAL MONITORING - Data collection, processing and analysis. 8. In considering the report of the Hydrobiologists' meeting, the Panel took note that the aquatic monitoring, in accordance with the established protocol, had continued Ehroughout the year. The monitoring data, collected since the beginning of the Progranrne activiEies from a wide representative sample of rivers throughout the operational area had now been stored ln the computer at Salford Universlty. Discussion was proceeding on methods of analysis; it was clear, however, from preliminary study that the effect of Abate had been minimal. Surprisingly there had been no evidence EhaE any organlsm, apart from Simulium dcnnosum had been adversely affec ted . 9. The Panel endorsed the vlew of the Hydrobiologists that at most sites there were tnsufficient |tpre-treatmenttr data. It therefore supported their proposal that the sampling prografime should be reorganized as descrlbed ln Appendix I. Ihis would ensure the acquisltion of pre-treaEment data from rlvers that will probably be brouglrt into the control programme and the contlnued saropllng of those for which pre-treatment data are already avallable. 10. For any future onchocerclasis control progranrne the i-mportance of collect,ing pre-treaEment data cannot be over-emphasized. The Panel felt that the view of the statisticlans that at least four years of such daEa be collected should noE be ignored, especially lf blackfly control is to be ext.ended to other areas in Africa. 311. The Panel supported suggesEions for cooperative study,between the hydrobiologists and theSalford team, to collect addltional calibratlon data that could enhance the value of the existing data set. L2. Whilst casual evidence suggested that Decapod CrusEacea (shrimps) were unaffected by Abate, the Panel reconrnended that they be kept under survelllance as this group might become lmportant. if other larvicides should be introduced. 13. Processlne and lysis of Data The Panel was informed of the formldable task wtrich faced the Salford Team, in collaboration wlth the statistical and computing units at l^lllO Headquarters in Geneva, in ensuring the compatibility and accuracy of the stored monltoring data. It underlined the importance of this work in order to enable the timely analysis of the data and reconrmended that the data handling system as presently developed be adopted. 14. The Panel noted that the analysis of the fish data had shown no apparent effect of the Programme on fish diversity or numbers. However, it was noted that some of the fish data had not yet been incorporated in the data set because of changes in the recording methods. It therefore urged that these data be included as far as possible because fishes are important, for the monitoring of long-term changes. 15. The Panel reconmended that brain cholinesterase analysis of fish be undertaken as a seParate study to give further supPort to the overall evaluation resulting from the monitoring Progralrme. The advantage of the cholinesterase test is that. it clearly separates exposure offlsh to organo-phosphorus compounds from that to other chemlcal compounds. E INSECTICIDES Larvicides16 The Panel was informed of the present arrangements for evaluating candidate larvicides. CDC Laboratories, Atlanta carried out both physical and chemical evaluations of the properties of such insecticides. Ttre New York Museum was carrying out tests on new formulat.ions using afixed trough system. Riverslde Laboratories, on the other hand, evaluated insecticides in ajar system and undertook field tests in smal1 rivers. A fourth laboratory, ORSTOM at Bouak6, using a floating trough system were testing new formulations in situ, and then promising compounds were tested on large-scale in rivers. A number of compounds were promising, e.g. chlorphoxim, methoxychlor, dimilin, chlorpyriphos-methyl, plrimiphosmethyl and Bacillus thuringiensis var. israelensis. 17. The Bouak6 iaboratory has also evaluated the effect on non-target organisms of most of these compounds. It appeared that chlorphoxim was somewhat more toxic than Abate, but Bacillus thuringiensis was aPParently innocuous to non-target fauna. Methoxychlor was promising but inlEs present formulation failed to k111 the last stage larvae of S.damnosum. As ambient temperatures influence the efficiency of certain compounds (negative correlation with some organo-chlorlne compounds and pyrethroids, and positlve correlation with organo-phosphorus compounds) results from temperate climates were frequently inappllcable in the tropics. 18. The Panel was asked by WHO to propose criteria for the acceptance of a candidate insecticide for field trials. Attentlon was drar"rn by the Panel to the work of the OECDEcotoxicological group, and the FAO Expert Panel on pesticides and the environment. The latEer grouP is presently preparing pre- and post- reglstration requirements for newpesticides and formulations. This work could be useful to OCp ln future. 19. The Panel suggested that the baslc criterla for acceptance were a compound's specificigy to Simullum damnosum, its low effect on non-target organisms and its low potential hazard to man, fish and birds. When the rtsks involved in the use of a compound had been clearly 4identlfied, it was up to the Governments Eo decide in consultation with OCP r,rhether to approve its use. 20. Abate Ihe draft review of the toxicological data related to Abate prepared by the Chairman was welcomed by the Panel. It reconrnended that the document should be further developed to make the title and content more specific to rrAbate as used in the vector control operations in West Africarr. Additional paragraphs should be added to describe assessment methods, application techniques and frequencies of application. Such a document updated from time to time, as necessary, would be useful to provide correct information to parties interested in the use of Abate for blackfly larviciding. 2L. the Panel was satisfied that Abate presently met the basic criteria expressed in paragraph 19 above, and as such can be used as a measure for comparing other pesticides. 22. Adulticides Although it was doubtful that larviciding could ever be replaced by adult control in the Progranrne, it could be a useful complementary method. However, more information concerning the resting places of the flies was still required. Ttre Panel recognized thaE pre- and post- treatment terrestrial monitoring would be required in the event of launchinS an adulticide Programne. F. FUTURE SCALE OF }4ONITORING AND RELATED STRUCTURES 23. Ttre Panel noted thaE the danger of a break in the collection of hydrobiological data in the r^rest of the Progranrne area had been temporarily averted by the agreement of ORSTOM to retain their Bouak6 group for two years. In the meantime, efforts were being made to train local people to take over the main routine monitoring work. In this respecE the Panel was informed of a meeting of representatives from those concerned hydrological instituEions in West Africa to be held in Ouagadougou on 9 and 10 October 1979. There were already several local hydrobiologists and technicians r,ilro could be engaged in such a new structure. Further technicians would be necessary and should be selected and trained from amongst secondary school leavers. The OCP might need to consider employing a hydrobiologist to be responsible for coordination among the monitoring groups and for promoting training courses. G. OTHER MATTERS 24. The Panel examined the Resolution No.5 of the 14th Session of the General Assembly of the International Union for the Conservation of Nature (Appendix II) which addressed itself to the eradication of disease transmitting vectors. The Panel felt that the IUCN was insufficiently informed on the extent to which the Onchocerciasis Control Prograrme was monitoring the hydrobiol-ogical change. The PaneI, therefore, addressed a letter of explanaEion to IUCN (Appendix III) and would encourage OCP to betEer inform the outside h7or1d through appropriate press releases and articles in the scientific press, of the special emphasis already being placed on the monitoring acEivities. 5APPENDIX I SAI'{PLING PROGRAI',IME RECOMMENDED AT HYDROBIOIOGISTS MEETING IN SAI,FORD, 24 - 26 SEPTEMBER 1979 Sampllng should be carrled out elther monthly, every three months or only once per year as follows, slte numbers belng glven ln brackets: Monthly samples Every 3 months Once per year At all the following sites fish will be sampled twice per year (viz. beginnlng and end of rainy season): Marahou6 (8 & 16) Sassandra (17) ot1 (11) Pru Asukawkaw Marahou€ (18) Sassandra (17) ori (11) Bagoud (7) Wtrite Volta (9) Bagou6 (7) I.lhite Volra (9) Red Volta (13) Black Volra (12) Leraba (1) Como6 (2) Nzi (5) Bandama (3) Black Volra (12) Leraba (1) Como6 (2) Nzi (5) Bandama (3) With regard to the Pru rlver fish samples wlLl be taken every two months in order to obtaln pre-treatment data. Every effort should be made to maintaln Ehe monitorlng prograrme on the Red Volta during 1979. 6APPENDIX II INTERNATIONAL UNION FOR CONSERVATION OF NATURE AND NATURAL RESOURCES 14TTI SESSION OF TIIE GENERAL ASSEMBLY OF IUCN ASIIKIIABAD, USSR, 26 SEPTEMBER - 5 oCTOBER 1978 RESOLUTIONS Resolutions on maior issues 5. Eradication of disease-transmitting vect,ors RECOGNIZING thaE the presence of disease-transmitting vectors, especially those of trypanosomiasis and onchocerciasis has severely restricted man's occupation and use of large areas of Africa, and that those areas are of great value to the peoples of the countries concerned, particularly because of the natural fauna and flora preserved within them; CONCERMD that proposals for blanket eradication of disease vectors over very la::ge areas of African savanna include nationaL parks and reserves; that operations have already begun to affect the Okavango swamps, Botswana, and Ehe natlonal parks of Upper Volta, Niger and Benln and pose direct, threats to the future of these parks, Ttre General Assembtv of IUCN, 5 October 1978 at its 14th Session, Ashkhabad, USSR, 26 September - RECOMI'IENDS to the governments and multilateral and bilateral aid organizations of all countries concerned, that the attempted eradication of disease vectors, such as tseEse flies, should not be carried out in marginal lands, and elsewtrere only as part of an lntegrated development programne, planned in accord with recognized conservation principles in precisely circumscribed areas ; RECOMMENDS further that, r.*rere atEempts at eradication take place close to protected areas and areas of comparable ecological value, the strictest measures be Eaken to ensure that the effects do not damage the characteristics of protected areas. 7APPENDIX III cfo oCP World Ilealth Organization 1211 Geneva 27 Snl t.zer land 28 September L979 Ttre Dlrector General International Union for Conservatlon of Nature Morge s Swltzerland Dear Sir, We, members of the Ecological Panel of the Onchocerclasis Control Programne of the World HeaIth Organlzatlon were dlsturbed by Resolutlon No. 5 passed by your organization, as we feel that it is founded upon mlsunderstanding of the sltuation in West Afrlca. Our Panel, ilhlch is an independent body of scientlsts who owe no allegiance to WHO, was set up to oversee the envlronment.al effects of OCP. We therefore are futly aware of all that has been done and of the extenslve monitorlng being undertaken. We can assure you EhaE the control of blackflies in the area is not resulting in any measurable effect upon flshes and wildlife, despite over four years of treatment in some rlvers. We would also point out that, as Simullum damnosum the vector of onchocerciasis, can fIy hundreds of kilometres, lt is essentlal to treat entire areas to control the disease. It is not therefore possible to leave any length of river untreated. You are no doubt aware that at present the only effectlve way of controlling onchocerciasls is by attacklng the vector fly and that the prevalence of blindness in adults in affected areas varies from 1O% up to 4oil. We have not responded before because we meet only at yearly intervals, but we hope that this letter will clear up wtrat clearly is a misunderstandlng. We also are deeply concerned with preservatlon of the environment. Yours truly, J.H. Koeman (Chairman) Agrlcultural Universlty Wageningen, The Netherlands. H. Gllles Llverpool School of Tropical Medicine UK H . B.N. Hynes University of Waterloo Canada Copy to Steerlng Committee OCP-WHO 8APPENDIX IV LIST OF PARTICIPANTS Members of the Ecolosical PaneI Professor C.H.I"1. Gi1les, Professor of Tropical l"ledicine, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L35 QA, United Klngdom of GreaE Britaln and Northern Ireland Dr H.B.N. Hynes, Department of Blology, University of Waterloo, WaEerlP, Ontario, Canada N2L 3G1 Professor Dr J.H. Koeman, Head, Department of Toxicology, Agricultural University, De Dreyen 12, Wageningen, The Netherlands (Chairman) Dr C. D6joux, Director, ORSTOM Hydrobiological Laboratory, B.P. 1434, Bouak6, lvory Coast Dr F.J.H. Fredeen, Entomology Division, canada Agricultural Research station' 17 Science Crescent, &s!@g, Saskatchewan STll OX2, Canada Dr Robert E. Lennon, P.O. Box 74, L:!rr9glg, Maine 04451 , United States of America Professor S. Ulfstrand, Department of Zoology, Uppsala University, Box 561, S-751 22 lJppsaLa, Sweden University of Salford Dr C.P. Fairhurst, Department of Biology, University of Salford, St1lfo4 M5 4WT, United Kingdom of Great Britain and Northern Ireland Dr S. Frost, Department of Biology, University of Salford, Salford M5 4WT' United Kingdom of Great Britain and Northern Ireland Dr M. Pugh Thomas, DepartmenE of Biology, University of Salford, Eqlfor.d M5 4WT, United Kingdom of Great Britain and Northern Ireland Technical Secretariat to Eco al Panel Mr C.G. Groom, Senior Officer PPU, Agricultural Services Division, Food and Agriculture Organization of the UniEed Natlons, Via delle Terme di Caracatla, OOIOO @' Italy Dr F. Henderson, Food and Agricrrlture Organizatlon of the United Nations, Via del1e Terme di Caracalla, OO1OO @, ItalY Mr J.D.M. Iularr, OCP Liaison Officer, World Health OrganizaEion, 1211 Geneva 27, Switzerland Dr J. Odetoyinbo, World Health OrganizaEion, Regl-onal Office for Africa, P.O. Box No. 6, Braz i lle , Congo Dr G. Qu6lennec, Pesticides Development and Safe Use, Divlslon of Vector Blology and Control, World Health OrganLzation, Avenue Appia, LZLL Geneva 27, Swltzerland Temporarv Advisers 9APPENDIX IV continued Mr J.F. Wa1sh, Chief, Vector Control Unit, Onchocerclasis Control Progranme, B.P.549, ouagadougou, Upper Volta Dr G. Zerbo, Vector Control Unlt, Onchocercl-asis Control Progranane, B.P.549, Ouagadougou, Upper Volta