Expert Advisory Committee: report of the ninth session, Ouagadougou, 13-17 June 1988

Onchoccrciasis Control-programme ltr &est Africa Programme de Luttc contre I'Onchocercose en Afrique de I'Ouest. JOINT PROGRAIITME COMMITTEE Office of the Chairman JOII.IT PROGRAMME COMMITTEE Ninth session Dakar. 29 JPC . CCP COMITE CONJOINT DU PROGRAMMEBureau du Pr€sident JPc9.3 (ocP/EAc/88. 1 ) ORIGINAL: ENGLISH September lgBB Page 2 5 o 9 10 10 10 11 11 75 76 November - 2 December 19BB Provisional agenda item 7 List of participants Executive Summary ONCHOCERCIASIS CONTROL PROGRAMME IN WEST AFRICA EXPERT ADVISORY COMMITTEE Report of the ninth Eession0uagadou@ CONTENTS 27 A B c D E F G H I J K L M N 0 P o R Opening of the session Election of Chairman Adoptlon of the agenda Follow-up of EAC.B reconmendations ..Matters arlsing from the eighth session of the JpCReport of the ninth session of the Ecological GroupReview of vector control_ operations Review of epidemiological evaluation activities ...Ivermectin and results of trials ....Modifications to the plan of Operations for the thiPhase (1985-1991) .... Review of the Onchocerciasis Chemotherapy project Progress report on epidemiological modelling . ... ..Research Devolution 0ther matters Date and place of EAC.10.... Adoption of the report Closure ol the session rd Financial 77 1B 79 ZU 22 23 23 23 Annex I Report of the ninth session of the Ecological Group 24 JPcg.3 (ocP/EAC/BB. 1 ) page 2 LIST OF PARTICIPANTS Mernbers Dr Y. Aboagye-Atta, Resident Medical Officer, Department of Health and Nuclear Medicine, Ghana Atomic Energy Commission, P.0. Box 80, Legon, Accra, Ghana Professor T.A. Freyvogel, Swiss Tropical Institute, Socinstrasse 57, 4O5f Basle Swi tzerland Dr N.G. Gratz, Chemin de Ruisseau No.4, 7291 Commugny, Vaud, Switzerland Dr C. L6v6que, Institut franqais de Recherche scientifique pour 1e D6veloppement en Coop6rat,ion (ORSTOM) , 213, rue La Fayerte, 75480 Paris Cedex 10, France Professor D.H. Molyneux, Department of Biological Sciences, University of Salford,Salford, M5 4WT, United Kingdom Dr D. Qui116v6r6, Service d'Entomologie m6dica1e, Centre Pasteur, B.p Cameroon 1214, Yaound6 Professor A.S. MuI1er, Director, Hygiene, 6l tvlauritskade, 1Ot2 Dr J.L. Stockard, America Royal Tropical Institute, Department of Tropical Ad Amsterdam Netherlands 72807 Falmouth Drive, Colesville, Maryland 20904, United States of Professor A.M. T/njum, Department of Ophthalmology Rikshospitalet, Pilestredet 12,002/ 0s1o 1, Norway Dr P. Viens, Directeur, Centre of International Cooperation in Health & Development, Faculty of Medicine, University of Lava1, Qq6bec, Canada G1K 7P4 Wor1d Health Organization Dr E.M. Samba, Director, Onchocerciasis Control Programme, Ouagadougou, Burkina Faso Dr S. Accorsi, Epidemiological Evaluation Unit, Onchocerciasis Control Prograrnme, 0uagadougou Dr 0. Ba, Epidemiological Evaluation Unit, Onchocerciasis Control Programme, 0uagadougou Dr R.H.A. Baker, Vector Control Unit, 0nchocerciasis Control Prograrnme, Bamako, Mali Dr D.A.T. Baldry, Vector Control Unit, Onchocerciasis Control Programne, Ouagadougou Dr D.A. Carvalho, Coordinator, Director's Office, Onchocerciasis Control Programme, 0uagadougou Dr 0. W. Christensen, Consultant, 0nchocerciasis Control Programme, Geneva, Switzerland Dr Y. Dadzie, Epidemiological Evaluation Unit, Onchocerciasis Control Programme, 0uagadougou Dr A. Davis, Director, Parasitic Diseases Programme, Geneva Dr G. De So1e, Epidemiological Evaluation Unit, Onchocerciasis Control Programme, 0uagadougou JPC9.3 ( 0cP/EAc/88. 1 ) page 3 Dr C. D. Ginger, Project Manager, Onchocerciasis Chemotherapy Project, OnchocerciasisControl Progremme, Geneva Dr T. Godal., Director, Special Programme for Research and Training in TropicalDiseases, WHO, Geneva Dr J. Grunewald, Vector Control Unit, 0nchocerciasis Control Programme, Banako Dr P. Guillet, Vector control Unit, onchocerciasis contror progrnmne, Bamako Mr P. Kabor6, Vector Control Unit, Onchocerciasis Control Progrnmme, Ouagadougou Dr M. Karam, Epidemiological Evaluation Unit, Onchocerciasis Control programme, 0uagadougou Dr D. Kurtak, Vector control unit, Onchocerciasis control progrsmme, Bouak6,Cote d'Ivoire Mr J.D.M. Mam, Chief , OCp Liaison Office, Geneva Dr A. Moudi, PHC, AFRO, Brazzaville , Congo Mr C. Pharand, Chi.ef, Administration and Support Services, Onchocerciasis ControlProgramme, Ouagadougou Dr B. Philippon, Chief, Vector Control Unit, Bamako Onchocerciasis Control Programme, Miss M.L. Ravelonanosy, Progrnmme Officer, Director's Office, Onchocerciasis ControlProgramme, Ouagadougou Dr J.H.F. Remme, Chief, Biostatistics and Information Systems Unit, Onchocerciasj.sControl Progrnmme, Ouagadougou Dr A. S6k6t61i, Vector Control Unit, Onchocerci.asis Control programme, Bamako Mr J.E. Senghor, Information Officer, Onchocerciasis Control programme, Ouagadougou Mr A. Soumbey, Statistician, Biostatistics and Information Systems Unit,Onchocerciasis Control programme, 0uagadougou Dr Y. Yanagata, vector control unit, Onchocerciasis control programme, Kara, Togo Mr L. Yam6ogo' vector control Unit, 0nchocerciasis control progremme, ouagadougou Mr D.G. Zerbo, Vector Controt Unit, 0nchocercj.asis Control Programme, ouagadougou Mr J.B. Zongo, Socioeconomic Development Unit, Onchocerciasis Control programme, 0uagadougou Onchocerciasis Chemotherapy project Dr A.D.M. Bryceson, Hospital for Tropical Diseases, London, NWI OpE, United Kingdom Food and Agriculture ation of the Uni Nations Mr Cyril G. Groom, Senior Progranming Officer, 0ffice of the Director, AgriculturalServices Division, FA0, via derre terme di caracarla, r - oo10o Rome, rtaly ," ltl rt E ,{ '3 JPC9.3 (oCP/EAo/BB. 1 ) page 4 Committee'of SponSorinF Agencies Mr Bruce Benton, Onchocerciasis Coordinator, Population and Human Resources Division,Sahelian Department, The World Bank, Washington, United States of America Dr Bernhard H. Liese, Principal Tropical Disease Specialist, Population and Human Resources Department, The liorld Bank, Washington, United States of America JPC9.3 ( OcP/EAC/88. 1 ) page 5 EXECII]IVE SI]MMARY The ninth session of the Expert Advisory Committee (EAC) was held in Quagadougouat the OCP Headquarters from 1l to 7'l June 1pBB. The session was preceded by aninformal briefing session on the afternoon of 11 June which enabled the Committee to nove directly to the agenda at the opening meeting on the morning of 1l June. The sudden and untimely death in Ouagadougou of one of the EAC members, professorPatrick Hamilton, on the day before the session opened, deeply saddened all theparticipants in the Committee's meetings and cast a shadow over its proceedings. The Committee hras appraised of the considerable progress achieved in the field ofvector control, both in the Original OCP area where virtual interruption oftransmission had been maintained for another year and in the Extension areas whereoperations were no!, catching up with the delay in the implementation of the plan ofoperations foreseen a year ago (paragraphs 27 and 22). The progranme had copedsuccessfully with instances of lowered susceptibility to temephos which continued tobe used whenever the larvicide rotation scheme resulted in a reversion of resistance(paragraph 2J). Some concern was expressed in regard to the possibility of a changein aerial contractor by the end of 1989 with the inherent risk to the efficiency oivector control operati.ons; the Committee encouraged the Programme to ensure with aI1parties concerned that a procedure woutd be followed that would entail the leastdisruption or reductj.on of its cost/efficiency of aerial spraying (paragraphs ZJ to28) . The Committee noted with satisfaction the accelerated pace with which vectorcontrol was being pursued in the Extension areas. It was concerned, however, aboutrecent identification of foci of invasion of blackflies into Guinea in areas south ofthe provisional OCP boundary in Sierra Leone, and the implication of SimuliumSggllglsg in that part of the programme area as a potential transmitter of theblinding form of onchocerciasis. The Committee urged that further investigations beundertaken as a matter of urgency (paragraphs 33 t; 35). The achievements in the field of epidemiological evaluation as reported to theExpert Advisory Committee were impressive. Thev comprised the prepar.tio., of anepidemiological map of the Western Extensio., "re., ctmpletion of an ophthalmologiealsurvey in the Original OCP area, a comparative study between the severity ofonchocercal blindness in savanna and forest areas, Lonsiderable progress i.nimmunodiagnosis and in the specificity of DNA probes of O. volvuiusl as well as thecompletion of a simulium feeding and transmissio., e*perirnent (paralraphs l+r t.-+6i.The Committee was particularly interested in the grelt strides made in large-scaleapplication of i-vermectin and in the analysis of ihe data accumulating therefromwhich wilt help determine the future role of chemotherapy in oCp. The programme hrasencouraged to continue along the lines of the plan of action developed by theEpidemiological Evaluation Unit (paragraphs 49- to 55). A draft modification of the Plan of Operations for the Third Financiar phase wasapproved by the Committee with the inclusion of a few amendments (paragraphs !6 to59)' The Expert Advisory Committee also reviewed the accomplishments and futurestrategy of the Onchocerciasis Chemotherapy Project and commended the project on itswork (paragraphs 60 to 65). The committee paid special attention to the subject ofdevolution and laid^dohln a procedure for its future consideration of this issue(paragraphs 73 to 78). After a review of ocP activities in the field of applied andoperationar research a list of priority subjects for the research programme was drawnup (paragraphs /0 to 72). JPC9.3 (ocP/EAc/BB. 1 ) page 6 Some very prelininary results from exploratory simulations by the epidemiological model were shown to the Committee which encouraged the Programme to continue its efforts to develop and utilize the roodel for the purpose of facilitating future planning and progranming (paragraphs 66 to 69). Following its considelations of the various agenda itens the Expert Advisory Committee made the following recommendations: The aeriql spraying contract (i) The Programme staff should make a detailed appraisal of the whole subject of tendering and contract awarding processes, contracting options and contract duration. A1so, this matter should be taken up as a matter of urgency with all concerned, especially the Director-General of WHO and the Committee of Sponsoring Agencies(CSA), to determine what procedures might be followed to ensure the least disruption of efficient aerial spraying operations (paragraphs 27 & 28). Control of sources of reinvasion (ii) New sources of reinvasion, the widespread distribution of savanna vectors in Siema Leone and the possible vector role of S. soubrense should receive further detailed study, especially with a view to clarifying the southern boundary of the Extension area which might need to be moved further south than originally planned with possible operational and financial implications (paragraph 35). EpidemioloEical evaluation (iii) Ttre Prograrome's collaboration with outside laboratories should be continued in order to develop an immunodiagnostic technique applicable under field conditions and to refine the DNA probes for diagnostic purposes (paragraph 48). Large-scaIe ivermectin distqibution (iv) Activities related to further trials of ivermectin should be given the necessary priority and every effort be made to complete the plan of action as presented so as to provide information in time for its next session to enable decisions to be made on the further integration of ivermectin into the control strategy. Also the Mectizan Comnittee should be approached to streamline the delivery of ivermectin to the Programme which would act in this respect on behalf of the Participating Governments and stressed the need for NGOs supporting ivermectj-n distribution in the Participating Countries to adhere strictly to OCP procedures(paragraphs 54 & 55). Modifications to the Plan of Operations for the third Financial Phase (1986-1991) (v) The modified Plan of 0perations should be adopted (paragraph 59). Onchocerciasis Chemotherapy Project (0CT) (vi) The mandate of OCT should remain unchanged and due priority should be given to the development of a macrofilaricide. OCT should be supported as fu11y as available funds would permit and every effort be made to obtain external funding for other justified activities whenever possible. OCT should take advantage of drug screening facilities and its clinical- trials centres to identify and evaluate furtherpotential drugs, particularly those compounds which have proved activity against nematodes of veterinary importance about which some j.nformation is available on drug metabolism, pharmacokinetics and toxicology. The CSA should take the necessary steps to stengthen the EAC membership to enable it to monitor and revieh, OCT activities for the JPC (paragraphs 64 a 6l). JPC9.3 (ocP/EAC/88.1 ) page 7 EpidemioloEical modelling (vii) Development of the model should continue with emphasis on its potential rolein planning, management and, eventually, training (paragraph 68). Research (viii) Internal research meetings to review operational research and plan futureactivities should be continued to ensure maximum coordination of research efforts and collaboration within OCP. It also recommended that the applied research essential tothe functioning of the Programme acti-vities be maintained (paragraph 72). Devolution (ix) liHo/AFRo, with its knowledge and technical resources to support nationalhealth service planning, should give greater attention to OCp participating Countriesin preparing for devolution to them of responsibility for maintaining control of onchocerciasis. fn order to bring discussions on devolution to a more operational leve1 the EAC should be provided with the following prior to EAC.10. a) an overview of the technical aspects of devolution; b) a clear indication of what is understood by recrudescence, what type of epidemiological surveillance will be required and the criteria for usingivermectin; c) the view of IrIHO/AFRO concerning devolution now and after 1ppl; d) the report from the World Bank on the health infrastructure situation. Alternative systems of motivation other than cash incentives should be developedso as not to burden the countries with responsibilities they might not be able tocontinue after 1997 which could prejudice the continuing success of devolution(paragraphs 75,77 & 78). Forest OnchocerciasiS (x) A detailed comparison should be made of the observations of a USAID mission and OCP staff on forest onchocercj.asis in C6te d'Ivoire with a report submitted toEAC.10 (paragraph J!). JPC9.3(ocP/EAcl88.1) page B A. OPENING OF THE SESSION 1. The ninth session of the Expert Advisory Committee (EAC) was held in the headquarters of the Onchocerciasis Control Programme (OCP) in Ouagadougou from 1l to U June 1988. The session was opened by the Programme Director who referred to the technical briefing which had been provided to the nembers two days previously. He introduced and welcomed six new EAC rnembers, Dr Y. Aboagye-Atta, Prof. D.H. Mo1yneux, Dr D. Qui116v6r6, Dr J.L. Stockard, Professor A.M. Tdnium and Dr P. Viens, and continued by introducing Dr A. Moudi, the representative of Dr G.L. Monekosso, WHO Regional Director for Africa, and Dr A. Bryceson, Chairman of the last OCT Steering Committee. 2. Referring to the tragic and untimely death of Professor Patrick Hanilton in Ouagadougou on 12 June 1988, the Programme Director said that OCP had lost one of its dearest friends. A nan of honour and a gentleman, Patrick Hanilton had always been devoted to service and through his dedication to serving the Programme, had died in the field. Speaking on behalf of all present, the Programme Director referred to the utter shock with which the news of Patrick Hamilton's death had been received by menbers of the EAC and of OCP aIike. Referring to the very valuable contribution that, Patrick Hanilton had nade to the Programme, the Director considered it appropriate that the EAC and the OCP should establish a sma1l token ofl memory and acknowledge- ment. In this respect it was agreed to make a collection, which would be used for the purchase of some appropriate equipment to be donated to the Yalgado Ouedraogo Hospital, Ouagadougou, in which Patrick Hanilton had spent the last hours of his life. 3. Professor T.A. Freyvogel, Chairman of EAC.B, said that he had been deeply moved by the death of Patrick Hanilton. He considered himself honoured to have had the personal opportunity to work with Patrick Hamilton, which had enabled them to get to know each other and to establish deep and mutual trust. More than that, a true friendship had developed and lasted until the previous day. Echoing the feelings of the Progranne Director, Professor Freyvogel reminded participants that they had all lost a friend, a highly competent colleague and a person who was totally dedicated to his profession. At the present time, the most appropriate tribute that could be paid to Patrick Hanilton was to continue with the work in hand, in the same spirit as that which had been so characteristic of him. 4. With regard to the present situation of the Programme, the Programme Director stressed that the many technical and financial worries of 1987 had been largely superseded by very positive attitudes and approaches, which now permitted the Progranme to view the future with considerable optimism. He hoped that the Committee would reflect on three topics of cument concern to the Programme, as follours: (a) Recalling that larviciding had been the sole tool available for onchocerciasis control, it now had to be acknowledged that the microfilaricide, ivermectin, had been demonstrated to be a safe and useful supplementary measure for onchocerciasis control. The most appropriate and effective means of interlocking these control methods now needed to be carefully defined. (b) In relation to this same subject, it had to be recognized that some parts of the Programme area would, from now on, receive only ivermectin admj-nistration, while others would receive a combination of ivermectin and larviciding, with the latter probably becoming less intensive and gradually being phased out. Eventually blackflies would return to onchocerciasis controlled areas, but this should not be allowed to imply that there would be a return of the disease. It was now becoming a matter of some urgency that this be fuIly explained to the populations concerned who would be faced increasingly with this new situation; in this respect, National Onchocerciasis Committees had an important role to pIay. JPc9.3 (ocPlEAc/88. 1 ) page 9 (c) Devolution hlas a subject which had received nuch attention and thought by arr concerned, especially with regard to the handing-over of certain responsibilities to the Participating Countries. The Committee was assuredthat the Progranme would continue, untir it ca-me to an end in 1997, to collaborate closely with Participating Countries to ensure the progressive and conplete transfer of responsibil-ities. During this period, OCP would always be available to provide advice to and coLlaborate with the various national authorities concerned. B. ELECTION OF CHAIRMAN 5- In his opening address, the retiring Chairman reaffirmed that the EAC as aCommittee should remain functional for a long as the Programme was officially active. He considered that the three main tasks of the Committee remained unchanged, as follows: (a) To monitor critically and constructively the activities of the progremme,keeping in mind its primary objective. To fulfit this function effectively ,the EAC would need to receive the maximum amount of information andfeedback, and would have to view OCP activities with a considerable emount of imagination. (b) To offer sound advice and guidance to the Progranme, which the Committee could do effectively by virtue of it being independent of WHO and of any other organization. This independence was a very important feature of theCommittee and must remain unchanged if truly valuable advice was to be made available to the programme. (c) To maintain the confidence of the Sponsoring Agencies and of the Joint Progrnmme Committee. It was to be noted that, during the last five or moreyears' both the CSA and the JPC had sought increasingly the opinions and advice of the EAC. It was thus very important for the irogramme that the EAC continue to provide welr-founded reports and good advice. 6. He also underlined that the next ten years of the progrsmme would witness somevery significant developments: the availability of ivermectin for onchocerciasiscontrol and the possible development of a macrofilaricide, the development of aneffective diagnostic test for the detection of early infections, and the increasedtransfer of activities from the Progra.mme to Participating Countries. It wastherefore important to the Programme that, during this phase, there be a reasonabl-edegree of continuity in the membership of the EAa. However, he maintained that thechairmanship ought to be rotating, with a two-year duration, if possible.Finally, the retiring Chairman expressed his deepest gratitude to EAC members and toOcP staff for the opportunity he had been given to work closely with them over thel-ast three years. 7. Professor A.S. Mu1ler was elected Chairman, and, to maintain continuity andensure EAC representation at other meetings Professor T.A. Freyvogel was electedVice-Chairman for the ninth session of the EAC. JPC9.3 ( ocPlEAc/BB. 1 ) pa8e 10 C. ADOPTION OF THE AGENDA B. The following agenda was adopted by the Committee: 1. Opening of the session: Statement by Programme Director 2. Election of Chairman l. Adoption of agenda 4. Follow-up of recommendations of eighth session of EAC 5. Matters arising from the eighth session of the JPC 5. Report of the ninth session of the Ecological Group /. Review of vector control operations8. Review of epidemiological evaluation activities t. Ivermectin and results of trials 10. Modifications to the Plan of Operations for the third Financial Phase ( 1986-91 )11. Review of the Onchocerciasis Chemotherapy Project 12. Progress report on epidemiological modelling 11. Research 14. Devolution 15. Other matters: - Forest Onchocerciasis - Management Seminar - EAC members' visits to OCP area 16. Recommendations 1J. Date and place of EAC.10 18. Adoption of the report 1!. Closure of the session D. FOLLOW-UP OF EAC.B RECOMMENDATIONS 9, As the five EAC.8 recommendations requiring follow-up reporting by the Programme were all covered by individual agenda items, it was agreed that OCP would respond when the appropriate agenda items were given consideration. E. MATTERS ARISING FROM THE EIGHTH SESSION OF THE JPC 10. One member of the EAC reported that he had attended the eighth session of the JPC(Rome, l0 November - I December 1987) and had introduced the report of the eighth session of the EAC. A11 the EAC vj-ews, including the recommendation that control operati.ons continue to be based on larvicj.ding for the present and the immediate future in order to protect the core area, were accepted by the JPC. 11. In response to a question from EAC members, the Progremme Director stated that during its eighth session, the JPC had approved the supplementary budget for 1987 without comment. 12. The EAC was reminded that the JPC in 1986 decided to give responsibility for socioeconomic development to CSA which would report regularly to the JPC on progress in implementing the socioeconomic development programme endorsed by JPC.7. Socioeconomic developnent was therefore no longer within the mandate of the EAC. Based upon the JPC's decision, it was reported by OCP that the function of the Socioeconomic Development Unit (ECO) supporting the CSA by collecting, analyzing and disseminating socioeconomic information, and acting as liaison between the CSA, National Onchocerciasis Committees (NOCs) and Participating Government officials, woufd be transferred to the office of the Director. JPC9.3 (0cP/EAc/88. 1 ) page 11 F. REPORT OF THE NINTH SESSION OF THE ECOLOGICAL GROUP 13. The report of the ninth session of the Ecological Group (Annex I) was presented to the Committee. The following points were noted in particular. 14. The Group had been reassured by the efforts made by the Progranme's Vector Control Unit (VCU) to nake tarviciding operations more efficient with a resultarrt reduction in pesticide pressure on aquatic environments. Sone key factors had been the greater use of improved and cheaper formulations of Bacillus thuringiensis H-14 and the increased util-ization of teletransmitted hydrological data for the refinement of larvicide dosages. 11. The Group was pleased to acknowledge the great efforts made by national hydrobiological teams in the Original OCP area and in part of the Western Extension area (western Mali and eastern Guinea) to prepare annual reports on their aquatic monitoring and evaluation activities. 16. Although to a certain degree toxic to aquatic invertebrates, carbosulfan had not been shown to have a significant impact on fish in field conditions. The Progranne would contj.nue to study the effects of this larvicide on invertebrates, and, additional information would be obtained from riterature searches. 1J. The Group had requested the University of Salford to conduct an independent and complete analysis of all the Programme's hydrobiological data, with special attentionbeing given to the possible side-effects of permethrin and carbosulfan. Comparisons would also be made of the short-term and long-term monitoring techniques and results. 18. The Group had recommended that additionaf information on non-target organisms be collected in the Western Extension area, that ngh, gnmpling sites be selected in that area, and that screening of new larvicide compounds and formulati-ons be continued until larviciding operations could be significantly reduced or discontinued. The Group was pleased to report that a ten-year summary of fish sampling data had beenpublished and that a similar summary on invertebrates had now been submitted forpublication. 1p. The Committee commended the Group on its report and on the recommendations contained therein. It noted with satisfaction the increased responsibility forhydrobiological monitoring given to national teams (composed of scientific andtechnical staff) in the Western Extension area. While stressing that the time would soon come when research on the environmental effect of new larvicides andformulations would have to be phased-out, the Committee agreed that, for the time-being, such research should continue, especially on new formulatj.ons of B.t. H-14 and other compounds which might be able to replace chlorphoxim now out of production (see also section M. "Research,). 20. The Committee expressed the view that future reports of the Group should place rather less emphasis on current vector control operations, but provide more detailedinformation on the results of some of the more critical monitoring activities. G. REVIEW OF VECTOR CONTROL OPERATIONS 21. The EAC was informed that in an endeavour to catch up on time in theimplementation of planned activities in the Extension areas, large-scale vector control operations had been leunched in early 1!88 throughout the Southern Extensj,on area and in the Senegal River Basin of the lrtestern Extension area (involving much of western MaIi and part of eastern Guinea). Seasonal and selective larviciding operations were also being conducted in the Upper Niger Basin, Guinea, to suppress known sources of reinvasion. At the same time technical and infrastructural JPC9.3 (0CP/EAC/88.1 ) page t2 preparatory activities were being extended throughout the remaining part of the Western Extension area. 22. 'Ihe Conmittee was also assured that larviciding coverage was being maintained in the Original Progranme area, except for a large part of Burkina Faso where no aerial treatments had been made for several years. Over much of the Original Programme areait had been possible to reduce the intensity of vector control operations and to increase the number of treatment interruptions, without adversely affecting the entomological and epidemiological achievements. At the same time, and by improved management of the entonological evaluation network, the Programme had reduced significantly the number of vector collector teams as well as their composition from three persons to two. Insecticide resistance 23. The EAC was informed that, resistance to temephos in savanna species now occurredin most of the Original Programme area and in a very considerable proportion of the Southern and Western Extension areas. However, this resistance was stable and permanent in only a few localized areas. In the majority of river basins, there was a reversion under the larvicide rotation scheme, such that temephos could be used seasonally at high water when it was economicalty advautageous to do so. Recently, there had been a particularly dramatic reversion in the Upper Niger Basin in Guinea.Susceptibility to temephos had returned to pre-treatment (1985) levels. This wasprobably due to an outright population replacement with the new blackfly population coming from Sierra Leone. Susceptibility tests conducted on savanna, mixed savanna/forest and forest vector populations in that country had demonstrated normal susceptibility to a range of larvicides. 24. tatci.ng a broad overview of the resistance problem, the Committee commended the Programne on the ingenuity and intensity of its efforts to exploit fu1Iy the rotational use of its ful1 arsenal of larvicides to contain and, in some cases, to reverse the resistance problem. Aerial operations 25. The EAC was reminded that from the time the new aerial contractor had assumed responsibility for aerial operations in January 1987, the Programme had experienced a number of problems, especially with regard to larvicide release equipment fitted tohelicopters. However, as a resurt of many equipment modifications, and, of considerable efforts on the part of both the aerial contractor and the Programme staff, there had been an appreciable improvement in aerial operations over the last several nonths. 26. In response to a recommendation of the eighth session of the EAC ( L9B7), and, inthe light of experience in the past eighteen months in changing from one contractorto another, the Progremme was in the process of revising the Invitation to Bid to make it nore precise in relation to technical and other specifications. 27. In addition, consideration was being given to how the existing bidding procedurefor the selection of the next aerial contractor could be improved upon. The EAC commended the advance action being taken by the Programme to tighten up the specifications of the Invitation to Bid and the selection process and recommendedthat Progranms sf,gff make a detailed appraisal of the whole subject of tendering and contract awarding processes, contracting options and contract duration. 28. Noting that the current three year aerial spraying contract would finish at the end of 1989, the Committee expressed concern at the Programme being faced again with a possible change in contractor at a time when aerial spraying operations were under considerable pressure with the implenentation of vector control activities into the JPc9.3 ( ocP/EAc/88. 1 ) page 13 Western Extension area. While recognizing that a certain procedure had to be followed in accordance with WHO ru1es, the Committee was deeply concerned about the implications, in reLation to cost and risk to the efficiency of the operations, of a change of contractor at such a critical period. It recommended that this matter be taken up as a natter of urgency with all concerned, especially the Director-General of WHO and the Connittee of Sponsoring Agencies, to deternine what procedures night be followed to ensure the least disruption of efficient aerial spraying operations. 29. With regard to the operational aspects of vector control activities, the EAC was informed that considerable progress had been made during the last year, especially with regard to inproved cost-efficiency ratios. Atthough the Progranme had been faced with an expanded insecticide resistance problem, which required greater reliance onB.t. H-11+ and an increasing insecticide consumption overa11, and, it had launched ful1-sca1e vector control operations in the Extension areas, aerial operations had been conducted nore economically than during the previous year. The most importantfactors contributing to this success were: (a) reduced cost of some larvicides, especially B.t. H-14, resulting from competitive bidding in the procurement procedure; (b) greater use of B.t. H-14 during the dry season when the use of this product beceme cheaper than that of temephos; (c) more economical use of all larvicides and of aircraft flight hours, nadepossible by: (i) maxinal utirisation of teretransnitted hydrological data and the computerization of all aerial operations data, which had improved dosage accuracy, aircraft utilization and logistical support administration. In addition, sound predictive approaches had been madepossible with regard to larvicide dosages under changing river conditions and to the interruption of treatments; (ii) daily (hourly, if necessary) radio transmission of hydrologicar and dosage data to pilots in the course of their treatment circuits, in order to compensate for changing hydrological conditions and to reducepilot error. 30. EAC members were unanimous in acknowledging that the improvements in the efficiency of aerial operations were extremely impressive and a tribute to the Programme for the efforts that were being made to compensate for financial constraints. Entomological results ]1. Although there were some parts of the Progrcmme area in which problems continued because of stabilized insecticide resistance, replacement of forest vectorsby savanna vectors in high rainfall areas, peculiar hydrological conditions along river stretches below dnms, etc., the overall control situation was currently very acceptable. 32. From the end of 1987 there had been a marked improvement in the AnnualTransnission Potential (ATP) values over a large part of the programme area, withATP's in most localities being below the 100 1evel of acceptability. Although reinvasion was not completely prevented, dranatic reductions in ATP values in the classical southern Mali reinvasion zone had been recorded as a result of a selective and seasonal larviciding of sources of reinvasion located in the Upper Niger Basin,Guinea. Regrettably, the delayed start of selective and seasonal treatment of riversin the Southern Extension area in 1987, had permitted significant reinvasion of a JPC9.3 ( ocPlEAc/BB. 1 ) page 14 number of areas in the northern parts of Togo and Benin. Large-sca1e larviciding operations in the Southern ExLension area were now giving much more positive results. Activities in the Western Extension area ll. The EAC noted with sat.isfaction the progress which had been made byParticipating Countries in proviiling facilities and staff to support hJestern Extension activities. There h,ere now 1! operational bases in the area covered by western Mali, Senegal and eastern Guinea, from which entomological, hydrologicat and hydrobiological teams operated. The number of national entomological staff employed was now 273, but this figure woutd increase to 364 tn 1989. J4. Entomological research activities had focussed on rej.nvasion, vector speciesidentity and distribution, and the identification of infections in the vectors. There was recent accumulating evidence that flies emerging from large rapids along some of the rivers in northern Sierra Leone, e.g. R. Se1i, lrere capable of long distance migrations into eastern Gui.nea, and possibly also southern Mali/north-western C6te d'Ivoj.re. As a result of mainly morphotaxonomic and cytotaxonomic studies on speciesidentity, it was now known that savanna vectors are distributed over most of Sierra Leone which could be due to the replacement of primary rain forest by savanna cultivation. Simulium soubrense populations were more heavily infected with 0. volvulus than the associated populations of savanna species and could thereforeplay a major role in the transmission of the savanna form of onchocerciasis. ]!. The Commit,tee viewed wi.th concern the new information on sources of reinvasion, on the widerspread distribution of savanna vectors in Sierra Leone and on thepossible vector role of Simulium soubrense. It recommended that these subjects receive further detailed study, especially with a view to clarifying the southern boundary of the Extension area which might need to be moved further south than originally planned with possible operational and financial implications. In this connection, the Committee was informed about the plans to treat suspected sources of reinvasion located in Sierra Leone already from 1989. Larvicide research 36. The Committee was informed that pyrachlofos, an organophosphate, was a potential replacement for chlorphoxim. It was less toxic to non-target organisms than chlorphoxim and was effecti.ve against temephos resistant strains. Sufficientquantities would not be available for operational trials until early 1989. 37. Alternative pyrethroids were being considered as possible replacement for permethrin but all were extremely expensive except one, cyphenothrin, a quantity of which had been ordered for triaI. 38. The manufacturers of B.t. H-14 were continuing to provide more concentrated formulations for assessment and some of these looked promising when used at operational dosages 30 to 40% Iower than the current formulation. The formulation characteristics of previous samples when supplied in industrial quantities had not proved consistent. However, the manufacturers were optimistic that they had overcorne these problems. 39. It had been decided not to continue with further testing of Insect Growth Regulators. JPC9.3 (0cP/EAc/88. 1 )page 15 Entomological Research 40. fne Committee was provided with documents providing fuI1 details of the entomological research being undertaken by the Progrnmme. It was recognized that most of the research was operational in character and had to be carried out in the Programme area' nostly by Programme staff themselves or with the help of consultants(see section M for a fu1l list of research activities). H. REVIEW OF EPIDEMIOLOGICAL EVALUATION ACTIVITIES 4t. tn order to estimate the population infected and blinded by onchocerciasis a randon sample of 155 villages was selected in Senegat, Guinea and western MaIi. Theinformation collected will serve as base line for the evaluation of the control effect and to determine priority areas for i.vermectin large-sca1e treatnent. A sanple of 182 vil1ages, not randomly selected, were surveyed prior to this. It was estimated that 700 000 people were infected with onchocerciasis in the area studied with 10 000 blind due to this disease. The Upper Niger river basin, a section of theGanbia river, the southern part of the Dakoye river and the area of Tienfala were athigh risk of onchocercal blindness and had been selected for ivermectin treatment. 42. Preliminary results of ophthalmological surveys carried out in 12 initia1y h5perendemic villages in the Original OCP area which had undergone satisfactory vector control for 12-11 years showed that only O.6fr of the population of 4gOO fraamicrofilariae in their eyes. Accordingly the incidence of onchocercal eye lesions inthe central OCP area should now be virtually zero. The prevalence of eye lesions inthe anterior segment of the eye and of blindness had decreased remarkably, but thisdecrease was less pronounced in the posterior segment of the eye. 43. en analytical method had been developed describing patterns of ocular onchocerciasis in relation to the intensity of infection i.n the community indifferent bioclimatic zones in the OCP area. The analysis showed that, in the savanna' the higher the intensity of onchocercal infection in the community, thehigher the prevalence of eye lesi.ons and of blindness. In the forest, lesions of theanterior segment of the eye were found only occasionally and onchocercal blindness was rare for comparable 1eve1s of intensity of infection. The savanna microfilariae seemed to be nore invasive to the eye as well as more pathogenic than forestmicrofilariae and this could explain the larger number of severe eye lesions as wel1 as higher blindness rates found in the savanna. This analytical ,etnod was being applied in the mapping of onchocerciasis patterns and in the determination of highrisk zones in the Western Extension area. 44. Rfter several years of sustained effort, immunologists collaborating with oCp had now obtained candidate antigens for immunodiagnosis which ranged in the low molecular weight of adult worm extracts. One of these antigens had been used in an ELISA based system for evidence of specific antibodies, with promising results. Specificity hadbeen the best so far obtained with insignificant or no cross-reaction with sera fromother human filarial infections. In relation to skin-snip results sensitivity observed in testing children's sera was as high as 972. the follo*-up of apopulation of children over a period of five years had enabled the detection of new cases one to four years prior to evidence of microfiliariae. 45. e Simulium feeding and transmission experiment had been carried out to assess thepotential infectivity of flies as a function of the intensity of infection of thehost. This involved 2) volunteers from an area which had been under control for along period and who had 1ow microfilarial Ioads. The results indicated that the up-take of microfilariae, as well as their development towards the infective larval-stage' were reduced in comparj.son with results for volunteers with high microfilarialIoads. It was planned to continue the study but with voLunteers with higher micro-filarial loads in order to reach a better understanding of the dynarnics of transmis-sion and eventual recrudescence within a broad spectrum of intensities of infection. JPC9.3 (ocP/EAc/BB. 1 ) page 15 46. Rfter the identification of the forest-specific-probe, a savanna-specific-DNA probe had been developed recently. Discussions h,ere underway with the collaborating laboratory concerned to make these two probes available for the testing of a large sample of worms collected over the years by OCP from various places in West Africa. 47. ttre Conmittee commended the Epidemiological Evaluation Unit on the work undertaken during the past year and on the progress made including the preparation of epidemiological naps. It recognized that the Unit was also heavily involved in the ivermectin trials (see section I). 48. Witfr regard to the research undertaken, the Comnittee recommended that the Programmers collaboration with outside laboratories should be continued in order to develop an imnunodiagnostic technique applicable trnder field conditions and to refine the DNA probes for diagnostic purposes. I. IVERMECTIN AND RESULTS OF TRIALS 49. OCp had embarked on an arnbitious programme of eight community triats of ivermectin with, as main objectives, to determine the risk of rare but serious adverse reactions, the acceptability of the drug and its potential for transmission control, as well as to gain experience in its efficient delivery. To date, more than 40 000 people were treated out of a census population of 85 OOO. Half the personnel involved in ivermectin delivery and monitoring of adverse reactions in the first five trials were nationals. In the last three trials the proportion of nationals was 751. 50. The trials had confirmed that ivermectin treatment results in dramatic reductionsin skin and ocular microfilarial Ioads, and therefore in the risk of disease. Adverse reactions had generally been mild and the few serious reactions encountered had been dealt with successfully by the monitoring teams. The risk of adverse reactions was not related to ivermectin dosage but depended almost exclusively on theintensity of infection of the treated patients. It was concluded that ivermectin r^ras sufficiently safe for utilization in the OCP area in mass distribution provided that an adequate level of post-treatment monitoring was assured. In one trial area large- scafe treatment with ivermectin resulted in a reduction in transmission of 70-75%during the first three months following treatment. However, the remaining leve1 was sti11 unacceptably high according to the criteria previously established by the Programme. Extensive entomological baseline data had been collected for five of the other trial areas. The results on the effect on transmission in those trials would be available early 1!Bp. !1. This work would be extended in 1989 and 1990 to cover 250 000 persons in 15different foci throughout the Programme area. Further evidence would be collected on the effect of ivermectin on transmission. Most of the foci had been selected because of the high rate of blindness but other epidemiological, as well as ecological and strategical, criteria lrere taken into consideration. Treatment would be carried out with or without paralle1 larviciding activities, depending on the area. 52. The EAC was informed about the setting up of a Mectizan Committee in connection with the free supply of ivermectin and that the completion of a questionnaj-re otherwise required for that purpose would not be required for the OCP countries in West Africa as the Programme would act as a guarantee. Furthermore, the Programme Director informed the EAC about his contacts with a number of Non-Governmental Organizations (NGOs) interested in supporting Participating Countries in large-scale ivermectin distribution in fu11 collaboration with OCP. !1. The EAC recognized both the unique quality and size of this effort which had to be decided, planned, budgeted and implemented at short notice and within varied and often difficult operational conditions. It had atso to be carried out r^rithoutprejudice to the already long-term planned activities and confirmed yet again the JPC?.3 (ocPlEAc/BB. 1 ) page 17 adaptability, competence and capacity of inter-disciplinary intervention that exists within OCP. The Programme riras commended on its efforts and its findings related to the potential use of ivermectin and for the way it had involved the ParticipatingCountries in the distribution of ivermectin in each country from the beginning. 54. fhe EAC recomnended that activities related to further triaLs of ivermectin begiven the necessary priori.ty and every effort be nade to complete the plan of action as presented so as to provide information in tine for its next session to enabledecisions to be nade on the further integration of ivernectin into the control strategT. Suggestions were made for field studies in such fields as the effect ofbi-annual treatments on the transmlssion of onchocerciasis and the possible macrofilaricidal effect of repeated ivermectin treatments (see also paragraph 61below) whil-e not ignoring the possibility of resistance eventually developing to thedrug. 55. The Comnittee also reconmended that the Mectizan Comnittee be approached to streamline the delivery of ivernectin to the programme which would act in this respect on behalf of the Participating Governnents and stressed the need for NGOs supporting ivermectin distribution in the Participating Countries to adhere strictlyto OCP procedures. J. MoDIFICATIoNS T0 THE PLAN 0F oPERATIONS FOR THE THIRD FTNANCIAL PHASE (1986-1991) 56. The draft docunent was introduced by the Progranme Director who briefly summarized the reason for modifying the Plan of Operations and stressed that all OCP professional staff had been involved in the preparation of the draft now beforethe Committee. He underlined that the proposed progranme for the three years inquestion (1989-1991) was based on larviciding as the principar means oftransnission-control with the possible use of ivermectin for specific purposes in certain areas, thus reflecting the recommendations made by the Expert AdvisoryCommittee at its eighth session. The Director mentioned that a p"Llinirrary estimateof US dollars 182 million was presented to the Joint programme Comnittee in 19g7 asthe budget for the entire third Financial Phase (t986-L9gL) and that the activitiesproposed in the modified PIan of Operations would bring the total expenditure for thePhase to that level. He stressed the need for the Programme being allowed to carryout the planned activities with a great deal of flexibility as hid been the case thusfar. 57. The Committee while fu11y supporting the proposals presented in the document considered certain modifications i.n the planned activities which might eventuallylead to cost-savings in case difficulties arose in holding expenditures within theproposed budget level. One such possibility could be to accelerate the cessation oflarviciding in the Original Progrsmme area but it was agreed that this wouldjeopardize the excellent resul-ts obtained so far and possibly prevent the programmefrom meeting its objective in that area. Another suggestion was to replace the gCp entomological- surveillance staff in the Original and Southern Extension areas bynationally employed personnel. It was pointed out, however, that such a change wasunlikely to result in significant budgetary advantages and could have legalimplications. It was further stressed that the entomological surveillance network inthese areas had been reduced to an absolute minimum and that any further cuts wouldbe counterproductive. 58. ttre Committee also considered the possibility of reducing or ceasing larvicidingin certain parts of the Extension areas. One such zone could be the northern part oithe Western Extension area where endemicity was low (an observed high transmissionpotential was in all likelihood due to zoophilic infection) and from where there wasprobably no onward f1y movement entailing transmission. However, such a decision should be based on solid technical and operational criteria. In any case if reduction in vector control in that area hrere to take pIace, larviciding of JPC9.3 ( ocP/EAc/BB. 1 )page 18 resistance foci would need to be maintained. After a thorough discussion, EAC concluded that at this stage it would be unwise to detract from the vector control operations as proposed in the Modifications document. It. Fina11y, the Committee was informed about the financial situation of OCP for the t999-799t period and of the efforts undertaken by the World Bank to close the current gap of around US $20 million between the approved budget estimates and the expected Donor contributions. The Progranme Director felt confident that, in the end, expenditure would not exceed the estimate indicated to JPC, in 1987. The Committee was of the opinion that any budget reduction would not only jeopardize the achievements of the Programme to date but would place at risk the long-term objective of the Progremme. The EAC recommended that the nodified Plan of Operations be adopted. K. REVIEW OF THE ONCHOCERCIASIS CHEMOTHERAPY PROJECT 60. tn line with CSA recommendations, the 0nchocerciasis Chemotherapy Project (OCT) had cut back its internal progrnmmes of target identification and drug discovery on the grounds that compounds selected for clinical trials j-n man should have completed most of their pre-clinical evaluation by 1!p1, so allowing field trials before the end of the OCP Progrnmme in 7997. 61. In addition to CGP 5140, two drug series could be seriously considered aspotentially capable of entering clinical triats against onchocerciasis, i.e. back-up benzthiazoles and phenylamidines from We1lcome. During 1988-1989, OCT clinical trial centres would start to evaluate, as potential macrofilaricides, multiple doses of ivermectin (or other avermectin/milbemycin analogues), and combinations of ivermectin with other registered drugs known to have effects on adult Onchocerca worms e ebbenzimidazoles, levemisole, metrifonate etc. Such combinations if successful couldprovide a rapid and cheap route to an oper.ational macrofilaricide. 62. However, in view of the known high fallout rate of drugs in clinical development, OCT considered that the lead compounds identified above did not constitute sufficient guarantee that a macrofilaricide would be forthcoming. Therefore advantage would be taken of the available screeni.ng systems of clinical trials centres, to identify and evaluate further potential drugs from the pharmaceutical industry, particularly those compounds which have proven activity against nematodes of veterinary importance and about which some information was available on drug metabolism, pharmacokineti.cs, toxicology etc. 53. The EAC noted a proposal to establish a Preclinical Drug Development Group to coordlnate and monitor the acquisition and testing of an increased number ofpotential macrofilaricides in O0T-supported screens. The Group, under the direction of Project Manager OCT, would direct drug development and advise the OCT Steering Committee. Creation and maintenance by the team of a computerized chemical and biological database for test compounds would ensure that all required preclinical work on active compounds would be carried out at the most appropriate time. 64. ttre EAC was favourably impressed with the work accomplished by OCT and commendedit on the manner in which it had addressed its area of responsibility given existing funding constraints. The Committee considered further that the benefit to be derived by OCP from a satisfactory macrofilaricide continued to be extremely important. It recommended therefore that the nandate of OCT remains unchanged, that due priority be given to the development of a macrofilaricide, that OCT should be supported as fu1ly as available funds would permit and that every effort be made to obtain external funding for other justified activities whenever possible. Such additional funds would permit OCT to continue a fu11 progranme while easing the overall pressure on funds required for OCP to meet other critical objectives through the third Financial Phase. Ttre Connittee also recommended that OCT should focus its efforts in close JPC9.3 ( oCP/EAC/BB. 1 )page 19 collaboration with the pharmaceutical industry on two drug series which could be seriously considered as potentially capable of entering clinical trials against onchocerciasis. It was essential that drug screening facilities and at least twoclinical trial centres be maintained. It reconnended that OCT take advantage ofthese facilities to identify and evaluate further potential drugs, particulirly those compounds which have proved activity against nenatodes of veterinary importance about which sone information is available on drug netabolism, pharmacokinetics andtoxicologlr. 55. ftre EAC also recommended that the CSA take the necessary steps to strengthen the EAC nenbership to enable it to nonitor and review OCT activities for the JpC. L. PROGRESS REPORT ON EPIDEMIOLOGICAL MODELLING 66. e report was presented to the Committee on the progress made in the field of applied modelling. A fu1l transmission model for onchocerciasis had been developed incollaboration with the Institute of Public Health of the University of Rotterdam anda computer sinulation programme was completed and inplemented on a new and morepowerful microcomputer at the OcP headquarters. Staff of different Units had assistedin the quantification of model paremeters and the first round of tests had shown thatthe model was capable of simulating the base epidemiotogical trends in the progra.mme and the results from the ivermectin trial in Asubende. A plan had been designed forthe detailed and systematic testing of the noder before the end of 198g. 67. rtte final aim of the transmission model was to provide a realistic prediction oflong-term epidemiological trends in the OCP area urra to enable the prospective evaluation of alternati.ve control strategies. One of the main questions to be addressed concerned the risk and dynamics of recrudescence and the question at whatstage vector control could be safely interrupted. The second prioriiy was theprediction of the inpact of ivermectin-based control in uncontrol]ed endenic areas and in recrudescence situations. Of direct operationat importance ri,as the prospectiveevaluation of strategies based on the combined use of vector control and ivermectinlarge-scale treatnent. 68' Some very preliminary results from exploratory sinurations were presented. It wassuggested that if recrudescence should occur, it could initially be tuilding up verysIowIy and remain undetected for several years. Post vector control surveillance would therefore have to be planned with a long-term perspective in mind. preliminarypredictions on the long-term impact of ivermectin-based control varied greatly according to the assunptions made concerning the effect of repeated treatment on theadult worms. The preliminary results highlighted the advantagLs of ivermectin as atool in disease control but it was more difficult to assess its potential as a toolto stop transmission. It was stressed that further testing of the model and the flnalresults from the ivermectin trials were needed before quantitative and more validpredictions could be made. The Connittee recommended ihat tne developnent of themodel continue with emphasis on its potential role in planning, ,rrr"g..ent and,eventually, training. 69. rne EAC discussed at some length questions of cessation of larviciding in thecore area and the subsequent risk of recrudescence of infection and disease. It wasagreed that there was a clear need for long-term surveillance under devolution. It was also realized that the detection of recrudescence would be practically impossibl-eby entonological evaluation methods because of the expected low level of infectivityin the vector which would necessitate the collection and dissection of massive 'mounts of f1ies. Long-term survei,llance would, therefore, have to be based uponepideniological evaluation nethods, preferably using a highly specific imnuno-diagnostic test. d JPC9.3 ( 0cP/EAc/88. 1 ) page 20 M. RESEARCH 70. The EAC reviewed the activities of OCP in the field of applied and operational research. The Committee noted that all information acquired from it by the Progremme could be viewed as the result of applied field research, essential to the efficient and optimal functioning of the Programne as well as supporting the devolution activities of the Progrnmme. 11. The EAC considered that in the light of the available information the following research areas, not listed in order of priority, should be regarded by the Programme as of high priority in either optinizing the cost-effectiveness of the Programne,providing alternative methods of control, or, most inportant, enhancing the quality of the information on which to base operational decisions: (a) continuing research towards the development of a nacrofilaricide; (b) continued development and application of epidemiological nodelling with the aim of providing the Programme with the best possible infornation on which to base operational decisions. In this respect, special attention would have to begiven to studies on the paraneters reLated to the effects of large-scaIe ivermectin distribution, on the effect of ivermectin administration on onchocerciasis transmission in the presence of vector control, and, on the relationships between vector infectivity and the intensity of infection in the hunan host; (c) continued evaluation of ivermectin as a tool for disease control and in the reduction of transmission after different numbers of treatments; (d) continued development of a serological test which would provide a rapid and easily applicable field tool for the detection of early infections in man, two to three years prior to nicrofilaria being detectable in the skin; (e) continued studies on the vector cytospecies in the Western Extension area(especially in Sierra Leone), and, on the relationships between cytospecies and the prevalence of onchocerciasis-related blindness, with a view to clarifying the epidemiological situation and to defining the southern boundary of the Programme area. For these studies to be made possible, it would be necessary to continue studies on methods of differentiating the adults of savanna and forest Simulium cytospecies; (f) the continuation and updating of evaluation of new formulations ofinsecticides provided to the Progranme and the testing of potential compounds submitted to the Programme through WHO PES; (g) continued monitoring of the susceptibility/resistance to larvicides in the operational area of the Programme; (h) the development of a technique for the identification of Ll stage 0.volvulusin Simulium da.mnosum s.1. using either DNA probes or imnunological metnoas wfricn would enable large numbers of flies to be processed rapidly, thus reducing the requirenent for individual dissections; (i) further development and application of DNA probe technology to identify anddifferentiate L3 Onchocerca of animal origin from o.volvurus in man, tofacilitate the aifferentiation of forest versus sarranna strains of 0.volvulus and, to evaluate their respective prevalence; JPC9.3 (ocP/EAc/88.1 ) pa9e 2L (j) the initiation of studies on the replacenent of rainforest vegetation by savanna/cultivation to determine the extent to which deforestation could influence distribution and bio-ecology of vector species, and, the distribution and severity of onchocerciasis (see also paragraph 34) 12. T\e EAC, impressed with the quality of research, would continue to encourage OCP to publish its findings but recognized that time and other constraints nade it difficult. The Committee noted that OCP had convened an internal research meeting in Ouagadougou in January 1988 to review its operational research and plan future activities and recommended that such neetings should be continued, thus ensuring maximum coordination of research efforts and collaboration within OCP. It also recommended that the applied research essential to the firnctioning of the Programme activitles be naintained, such research providing a base for improved cost-efficient control strategies which assist the Progranme in reaching its long-term objectives. N. DEVOLUTION 73. As ivermectin was progressively showing its capacity for disease control and its safety under conditions of nass treatment, the concept of devolution was entering a ne!e, more concrete phase. OCP's role should consist in field training of national human resources to carry out epidemiological surveys, mininal surveillance operati-ons and the safe, monitored distribution of ivermectin. An "Onchocerciasj.s Surveillance and Treatment Manual" had been drafted and would be revj.ewed periodically. OCP had also arranged with the eleven Participating Countries to coordinate their demands for ivermectin and to ensure that the manufacturerts minimal requirements were met (see also paragraph 12 above). 74. there remained however many aspects to be addressed. Ivermectin field trials aimed at controlling transmission were still ongoing. The type of surveillance required stil1 had to be identified. Ivermectin was a long-acting microfilaricide. The discovery of a macrofilaricide would greatly ease the efforts. The problems within some of the Participating Countries to carry out distribution of ivermectj.n needed to be solved. Incentives were having to be given to national staff. 75. EAC appreciated the overalL need to strengthen the health infrastructures in the countries concerned and to maintain a long-term coordination of effort amongst these countries to prevent the recrudescence of onchocerciasis. The Comnittee also reiterated that the WHO Regional Office for Africa would be the right channel for working with the countries in developing appropriate health structures. In this respect it welcomed the presence of a representative of the Regional Director and theinterest expressed in AFRO being involved. The Committee recommended that WHO/AFRO, with its knowledge and technical resources to support national health serviceplanning, should give greater attention to OCP Participating Countries in preparingfor devoluting to then of responsibility for naintaining control of onchocerciasis. 76. fne Committee was aLso informed of the responsibility given by the JPC to the World Bank to take the lead in arranging financing for the Participating Countries in respect to the various requirements of the devolution process including the improvement of health infrastructures. In relation to this a consultant had recently visited two of the countries. 77. The EAC recommended that, in order to bring discussions to a more operationalIeve1, it should be provi.ded with the following prior to EAC.10: 1. An overview of the technical aspects of devolution as seen by OCP staff as a basis for the preparation for individual countries of detailed and costed devolution proposals related to preventing the recrudescence of the disease through epidemiological surveillance and treatment with ivernectin. JPC9.3(0cP/EAc/88. 1 ) page 22 2. Answers by OCP to the following questions: (a) What is understood by recrudescence? (re-emergence of the disease or infection, how many cases and at what stage). (b) What t5pe of epideniological surveillance? (active/passive case detection, laboratory services required, etc. ). (c) Criteria for ivermectin use (what is the trigger point, how many people etc. ) The Committee felt that even if the details of epidemio-logical surveillance and treatment should change, a preliminary answer to the above questions would enable these activities to be fitted meaningfully into multidisease control activities of the national Public Health Systems. l. Recognizing the unique experience of the Regional 0ffice in its knowledge of health services in the Participating Countries, the view of WHO/AFRO concerning devolution now and after t997. lt was hoped that WHO/AFRO would take a morepositive approach to devolution as it related to the structural capacity of countries to carry it out. 4. ttre report from the World Bank on the situation of health infrastructures. 78. ttre EAC appreciated that, owing to the financial situation in nost of these countries cash incentives were being paid to nationals participating in the ivermectin distribution. It recommended, however, that alternative systens of motivation should be developed so as not to burden the countries with responsibili- ties they night not be able to continue after 1997 which could prejudice the continuing success of devolution. O. OTHER MATTERS Forest onchocerciasis J). Two reports, one from USAID and the other from OCP, and emanating from four studies dealing with onchocerciasis in southern C6te d'Ivoire, found different prevalences of blindness in the area. The reports were discussed and, as the two groups had apparently used different methods of sampling, the EAC recommended that a detailed comparison of the observations should be undertaken with a report submitted to EAC.1O. Management seminar 80. The EAC was informed that in 1986 when the Programme started to encounter serious financial problems, the initiative was taken by the Programme to review critically all activities and expenditure in an endeavour to reduce cost and to make all activities more cost-effective. Very considerable progress was made towards achieving these objectives through the convening of internal financial nanagement seminars early in both 1987 and 1988. 81. During those annual seminars representatives of all the technical units, of all the services of the Administratj,on and of the WHO/HQ in-house Management Consulting Group worked together to review systematically aII Programme activities and to make proposals for reductions in activities, personnel, supplies and other high-cost items of expenditure. Based on the proposals made during these seminars, and by adopting a zero-based budgeting approach, cost-estimates were made for the year's activities. 82. The EAC was pleased to note that the outcome of the seminars had contributed significantly to conserving funds which had then been used to accelerate the launching of large-scale vector control operations in the Extension areas. JPC9.3 ( 0cP/EAc/88. 1 )page 23 lAC members visits to the OCP area 83. SAC nembers hlere encouraged to inform the Progranme Director at an early dateabout their wish to visit the OcP area specifying their preferences in regard toactivities to be observed. It was considered essential that EAC menbers regularlyacquaint themserves with various aspects of field operations. P. DATE AND PLACE OF EAC.1O 84' tne tenth session of the EAC would be herd in ouagadougou throughout the weekcommencing 12 June 1989. Q. ADOPTION OF THE REPORT 85' ft'e report of the ninth session of the EAC was approved by the members at theclose of the session. R. CLOSURE OF THE SESSION 86' rtre session was closed by the Chairman after the Director had expressed hisgratitude, and that of his staff, to the members of EAC for their ,r.r.. failingsupport to the Progranne. 0n his part, the chairman thanked the ocp staff for theircontributions to the Committeers deliberations which, he hoped, would contribute tofurther progress of the progremme. JPC9.3 (ocPlEAC/88. 1 ) Annex I Pace 74 REPORT ON REPORT ON PROGRAMME TABLES 1 AND 2 MAPS 1 AND 2 APPENDICES 1 T0 3 REPORT OF THE NINTH SESSION OF THE ECOLOGICAL GROT'P BAMAKo, 1-4 MARCH lggg CONTENIS A B c D E F G INTRODUCTION ADOPTION OF THE AGENDA VECTOR CONTROL ACTIVITIES HYDROBIOLOGICAL MONITORING ACTIVITIES ANALYSIS OF AQUATIC MONITORING DATA .. Page 25 25 25 30 33 34 H I J K L M INDEPENDENT ANALYSIS OF AQUATIC MONITORING DATA REPORT ON LITERATURE SEARCH ON ENVIRONMENTAL DISTRIBUTION AND FATE OF CARBOSULFAN . RESEARCH ON NEli LARVICIDES AND FORMULATIONS ..... !'loRK PRoGRAMME FoR 1gB8-Bg OTHER MATTERS ..... ARRANGEMENTS FOR THE NEXT SESSION .... APPROVAL OF REPORT CLOSURE OF THE SESSION 34 35 3B 39 4o 4r 41 JPC9.3 (ocP/EAc/88. 1 ) Annex I Page 2J A. INTRODUCTION 1. The Ecological Group held its ninth session in Banako, Mali, from 1 to 4 March 1!88, under the Chairmanship of Professor K.W. Cummins. A list of participants is given in Appendix 1. 2. 0n behalf of the Programme Director; OCP clleagues and the staff of VCU Koulouba, Dr Bernard Philippon, Chief VCU, welcomed Group Members to Koulouba(Bamako). An expecialty warm welcome vras extended to Dr. H.H. de Iongh, the Group's new member, who was making his first attendance at a Group session. 3. The 19BB Annual Meeting of Hydrobiologists had been held in OCP Koulouba and at the ORSTOM Laboratory, Bsmako, immediately prior to the 1!BB session of the Ecological Group and it was noted that there had been excellent opportunities for some Group Members to attend both meetings. This had enabled national Hydrobiologists to have beneficial discussions with some Group Members, and to profit from having their own meeting chaired by Dr C. L6v6que, to whom the Programme was very grateful. ft was explained to the Group that Programme staff now felt in a much more optimistic situation than had been the case at the time of the l-ast session of the Group, when there had been a generally depressed atmosphere brought upon by serious technical and financial problems and the prospect of having to makedrastic cuts in the approved Plan of 0perations for 1!B/. The Programme had managed to survive the serious 1987 situation and its staff had learnt much about working under the influence of severe financial limitations. Early in 1988, tne Programme was stil1 facing many constraints and it was to be expectedthat problems would continue to arise during the course of the year. However, the technical situation was currently good and staff r/rere reassured by guarantees of continued funding. ADOPTION OF AGENDA The foll,owing agenda was adopted Report on vector control operations Report on hydrobiological monitoring activities Programme analysis of aquatic monitoring data Independent analysis of aquatlc monitoring data Report on literature search on environmental distribution andfate of carbosulfan Research on new larvicides and formulations Vlork programme for 19BB-89 0ther matters Arrangements for the next sessj,on Approval of report C. REPORT ON VECTOR CONTROL ACTIVITIES (a) Activities durins 1987 ana earl.y 19BB 6. Reference was made by Chief VCU to the Report of the Eighth session of theEcological Group in which it was explained that the spread of temephos resistance in savanna vectors, budgetary constraints and the continuing fall i.nthe value of the US doltar, had made it necessary to revise the operational planfor vector control in 1987. B 5 JPc9.3 (0CP/EAC/88. 1 ) Annex I F"c"-rt 7. The revised plan, which had been implemented, provided for: vector control as and when required in the Phase I-IV areas in order to maintain protection of the "core" area of the Programme; seasonal and selective larviciding of the main rivers in the Southern and Western Extension areas which were presumed to provide major sources of flies reinvading the original Progranme area; preparatory activities (entomological, hydrological, infrastructural, epidemiological, hydrobiological) in the two extension areas especially in western Mali, Upper Guinea and eastern Senegal, at the 1986 level of intensity; epidemiological research in Ivermectin, expecially to determine the effects of that drug on parasite transmission. B. In order that those activities could be successfully implemented, it had been essential to keep a very tight control over expenditure, especially over the high-cost components of vector control operations, i.e. aircraft flight hours and insecticides. In addition, the necessity to make substantial savings had resulted in a 25% cut in the staffing of entonological evaluation tea.ms. 9. It had also been necessary to adhere strictly and carefully to all monitoring activities (vector species identification, determination of the dynamics of biting vector populations, insecticide susceptibility testing, monitoring the intensity of parasite transmission, hydrobiological monitoring), and to implement the operational rotation of the Programme's fuIl arsenal of larvicides (5 in number), the latter activity also requiring to be very carefully reviewed on a weekly basis. 10. Formulations of Bacillus thuringiensis H-14 (B.t. H-14) had increasingly replaced temephos as resistance to the compound had spread. However, it was very reassuring to note that improved formulations of B.t. H-14 had become available and that, due to sharp competition between manufacturers, the price of this product had fal1en by about 402. 11. Other economies had been achieved by greater optimization of treatment methods and larvicide consumption, which had been facilitated by the increased utilization of computerized aerial operations and hydrological data. The greater use of teletransmitted and computerized hydrological information had enabled vector control personnel to: make more accurate and selective treatments; predict changes in river discharge rates which in some cases allowed treatments to be suspended much earlier Lhan would have been possible from an analysis of conventional hydrological information. 12. Overall, the entomological results obtained had been some of the best recorded during the last few years. There had certainly been problems in the south-eastern and western invasion areas, but it was worthy of note that there had been a significant improvement in the entomological situation along the western boundary of the original OCP area. At most vector catching stations, the Annual Transmission Potential (ATP) had fallen to below 100 (the threshold of transmission acceptability). This improvement was attributed to more extensive larviciding operations in presumed sources of reinvasion further to the West. JPCg .3 (ocP /EAc/ 88. 1 ) Annex I Page 27 13. Despite the very careful planning and implementation of vector control operations to eliminate sources of reinvasion in the Southern Extension area,those activities cnme close to resulting in failure. The late starting oflarvicidin8 (Apri1 instead of February) which had permitted a build-up of vectorpopulations hlas obviously an important factor. It was also possible thatlarvicide applications had been made far too selective. 14. Attempts to suppress sources of reinvasion in the western part of the origina]- Programme area had been much more successful than in 1986 in terms ofintensity of transmission. However, there had stilI been a significant reinvasion of Mali and for a variety of reasons it had not yet been possibLe toidentify precisely the rej.nvasion sources responsible. Movement of flies fromSierra Leone into Guinea and possibly onward into Mali was a possibility. 75. Turning to the situation in March 1988, it was explained that all vectorcontrol activities were of a strictly dry season character. B.t. H-14 appliedto selected rivers was the only larvicide in use. Treatments-h"d b.e1 suspendedfor several weeks along many rivers and further suspensions were anticipatedbefore the onset of the 1!BB wet season. (b) Review of the revised vector control trateqv for 1988/89 76- Because of the savings made in 1987 it was nohr possible to embark upon a more extensive plan of operations for l98B/89 than had been endorsed by the JpCin Decembe! f982. Accordingly, the vector control strategy for the remainingpart of lpBB and for early 1989 had been revised and was now being implemented. t7. Ttre revision embraced the following activities: (i) routine larviciding as and when necessary i.n the "core" area; (ii ) (ii j. ) (iv) (v) (vi ) (vi j. ) fuI1 vector control operati.ons in the Southern Extension (commencedFebruary) and in the north-eastern part of the lrlestern Extension,i.e. most of western Mali and a smarl part of northern Guinea(scheduled to commence in April); selective vector control operations in the Upper Niger and theSankarani basins of Guinea to suppress presumed sources of reinvasion (scheduled to commence in mid-March) and associated entomological studies on vector movements; selection of catching points and of breeding sites to be kept under surveillance, the definition of f1y sampling schedules, and theimplementation of a system of data collection to ensure appropriate coordination between treatment and evaluation activities; implementation of entomological studies in sierra Leone (vectoridentlfication/distribution, infection rates, breeding siteproductivity potential) ; reactivation of preparatory activities in all other parts of theliestern Extension area (recruitment and training of national staff, establishment of operational bases, procurement of equipment and supplies, installation of radio network, construction ofhydrological stations) ; coLlaborative VCU/EPI/BIS research on ivermecti,n. JPC9.3(ocP/EAcl88.1 ) Annex I Pac. 28- 18. While the report of the 1t8/ session of the EAC had deplored a 3-year delay in the inplementation of the Western Extension, the new strategy for 1988 would enable the delay to be reduced to only one year. (c) Anticipa ted activities for L9B9/9O 19. In accordance with the JPC mandate to continue with full-scaIe vector control operations, it was anticipated that there would be complete extensions of larviciding operations into Senegal (Senegal and Ganbia river basins) and central Guinea (Upper Niger and Bafing basins in 1989), in the Western Extension area. 20. 0n the other hand, it was expected that vector control operations in the "core" area would be progressivly reduced, as ivermectin was introduced into areas where there were epideniological justifications for its use (areas where there had been repeated larviciding shortcomings, where there were persistent pockets of infection and where it was necessary to suppress residual infections). (d) The philosophy and implementation of measures aimed at overcominE the problems of insecticide resistance and budsetarv constraints durins 1CB7lBB 21. It was recalled that resistance to the organophosphates, temephos and chlorphoxim, had first appeared in the forest species S. sanctipauli (or relatively 1ow vectorial significance). Levels of resistance had always and characteri.stically been very high and persistent. 22. In contrast, organophosphate resistance in savanna species had been at a nuch lower level of severity and had usually been much less stable/persistent. The latter characteristic had been attributed partly to the genetic resistance mechanism, partly to gene dilution in populations which continually receive an influx of susceptible flies from untreated sources of reinvasion, and partly to less intensive selective pressure. 23. It was quite clear that in some areas, resistance had developed spontaneously through the selection of resistance genes within the population. In other areas it was deduced that resistance had either been imported through classical reinvasion movements of flies or by what is now referred to as "reverse reinvasiontt, i.e. dry season fly movements from the north-east under the influence of the Harmattan wind. Another possibility was that resistance had resulted from hybridization. 24. The conclusion derived from carefully conducted experimental studies of these phenomena was that, if temephos usage was discontinued at the first instance of treatment failures being observed, a serious problem could be avoided. Under such circumstances the judicious use of B.t. H-14 and other replacement compounds could return the level of temephos susceptibility to normal and permit temephos to be effectively reintroduced as an operational larvicide for short periods when it was economically justified, i.e. under wet season conditions. 25. Faced with the combined problems of resistance and budgetary constraints it had been necessary to introduce an extremely tight and efficient management system for larviciding operations: JPC9.3 ( ocP/EAc/88. 1 ) Annex I Page 2) - to slow down the developnent and spread of resistance, - to maintain satisfactory levels of vector control once resistance had appeared and/or to regain normal susceptibility levels, - to minimize the risks of more toxic replacenent compounds having adverseeffects on aquatic non-target organisms, - to nake all vector control methods and strategies as cost-effective aspossible. 26. The Group commended the VcU on the excellence of these management neasures,fully realizing the trenendous efforts that must have been made io ensure thatthe intended objectives were attained and sustained. It considered that thebenefits which had accrued and which continued to have a significant influence on the future course of the Programme, were of significant relevance far beyondthe speciarized interests and concerns of the Group. Accordingly, furtherdetails of the current Eanagement procedures for vector control are attachedhereto as Appendix 2. . The following statistics on larvicides dispensed duringthe last three years (in litres of formulation) also vouch for the soundness ofthe current manageEent strategy: Compound 1985 1986 1987 Temephos Chlorphoxim Permethrin Carbosulfan 384 581 3.3/) 299 r55(7.2/) 130 118(35.7'l) 277 L6g(2.7'l) 94 562(18.01) L7 376 173.21) 70 BB2(L6.91) 9 856$9.41) 05Fo/30(71 5) 2 967(o.Bt) 10 338(2.51) 5 286(1.4%) 18 84913.6/,) B t24(t.g/.) 9 1 75 9l 0 ) Totals 365 396 525 LL9 4tB 554 27: the figures presented above show that there r^ras an economy of more than100 000 litres of larvicides in 1!8/, compared to the previous year, even thoughthere had been a signficant spread of temephos resistance (see illaps't and 2 forths situation in early 1988), and more geographically extensive larvicidingoperations, especially in the western and Southern Extensions. B. t. H. 14 JPc9.3 ( 0oP/EAC/88. 1 ) Annex I Page lO (e) Comment bv the Grouo 28. The Group very much appreciated the efforts made by the Programme with a view to optimizing aerial larvicide treatments in order to reduce the quantities of larvicides used. However, certain simulations had implied that localized over-dosing would be necessary, even though the overall quantity of larvicide applied to a given stretch of river would be considerably reduced. The Group agreed that, even in the light of such a prediction, further tests with B.t. H-14 could be conducted. In the cases of temephos and chlorphoxim, the Group advised that limited tests could only be carried out if a good surveillance of the non-target fauna was assured. Overdosing with permethrin and carbosulfan shoutd not be practised for the time being. D. REPORT ON HYDROBIOLOGICAL MONITORING ACTIVITIES (a) Annual Meeting of Hydrobiologists 29. The 19BB Annual Meeting of Hydrobiologists (OCP, ORSTOM and National Services) responsible for aquatic monitoring throughout the Progranme area, was held in Bamako during 28 and 2! February 1988. The meeting which was chaired by Dr. C. L6v0que was also fortunate in having the participation of two other Ecological Group Members (Drs D. Calanari and M. Yasuno) during the second day. Participants were drawn from the OCP, from ORSTOM and from the national hydrobiology teans of C6te d'Ivoire, Ghana, Guinea and Ma1i. 30. Most progress reports on national monitoring activities over the last year had been presented to the Programme (except for that on invertebrate sampling in Mali) in a timely fashion and in a much more standardized format. Once again, the Group acknowledged the appreciable improvement of the technical quality and literary presentation of the national reports. 31. Unfortunately, due to unavoidable delays in the procurement of equipment and supplies, the ichthyological team of Mali had not been able to commence fulI-scale monitoring operations until mid-1987. The period covered by their activities was therefore far too short to enable them to present substantial data. 32. From the results obtained in the central part of the Programme area(R. Bandama) it appeared that there had been no discernable adverse effects of carbosulfan treatments on fish fauna. Juvenile forms of many fish species had been observed throughout the treatment period. 33. The increase of Schilbe mystus in fish catches at different monitorlng stations in the "core" area confirmed that fluctuations in abundance observed for that species were independent of larvicide applications. 34. Although catches of Petrocephalus bovei had decreased sharply in recentyears there was nov, sound evidence from monitoring statj-ons that populations of this species r^rere nohr on the j.ncrease. 35. The national hydrobiologists profited from personal contact with some Group Members to express their suggestions for enhancing the value of monitoring activities and to make some recommendations, as presented below: (i) They hoped that the Group would look favourably on their desire to conduct associated research, the results of which would allow them to more effectively interpret monitoring results. Two research topics were highlighted as being important, JPc9.3 (0cP/EAc/88. 1 ) Annex I Page 11 - studies on the verticaL distribution of invertebrates during drift,the fate of these organisns in pools and the utilization of simplebiotic indices, such as the Cairn's index, other measures ofdiversity, or the relative abundance of functional groups, - studies on the reproductive cycles of certaln fish species in relation to various environnental factors. (ii) They also wished to receive information on the fate of B.t. H-14toxins and their eventual persistence in the environnent. 1tt ,as agreed that some Group Members wourd provide assistance in this matter. ) (iii) They also indicated their desire to study the problems of the reducti.on of Tricorythidae which was coincident with B.t. utilization at some monitoring stations, and, the problem ofincrease of some Baetidae despite their sensitivity to all chemicallarvicides. (iv) Ttrey considered it desirable to try and establish a provisional nodel for the impact of insecticides (according to chemical family)taking into account the short-term effects observed in mini-guttertests and long-tern effects recorded under riverine conditions. 36. The Group reviewed with great interest the various findings presented atthe Annual Meeting of Hydrobiologists, accepting nany of the results with considerabLe satisfaction. T'he Group's views on the reconmendations presentedin paragraphs 35(i) to 35(iv) above, are presented later in this r.port, underSection J(a). (b) Surveil of the aouatic environment 37 - one of the recommendations of the eighth session of the Group had been that OCP hydrobiology teams take responsibility for the surveillance of aquaticinvertebrates in the original Programme area. Accordingly, this recommendationhad been implemented during the following surveillance session, in November1987. It was noted that because of the treat distance between the nonitoringstations and OCP/HQ, it took L2-2o days each month in order to visit arrstations. This had left the teams with little time to devote to assoclatedlaboratory work. 38. rn addition, the ocp teams had been responsible for evaruating the environmental impact of certain "new" pesticides. This had greatly increasedthe vorume of sampling, the numbers of days spent in the fieid, and, further reduced the time avaitable for laboratory investigations. Nevertheless aII the samples collected in November and December 1987 during routine surveillances andall those obtained from studies of neh, compounds had been processed. From the experience gained, the following points were underlined: (i) This system had enabled the OCP to obtain a very good knowledge ofall the monitoring stations and had permitted a better follow-up ofthe qualitative evaluation of the invertebrate fauna of the rivers concerned. (ii) It had also resulted in standardization of identifications which were made by the same team, thus permitting greater comparatibilityof the results. JPC9.3 ( ocP/EAc/88. 1 ) Annex I Page l2 (iii) The stations at Banboi (B1ack Volta, Ghana) and Gans6 (Como6, COte d'Ivoi.re) were not well suited to the collection of invertebrates fron running water, especially at the end and at the beginning of the year when there was virtually no river fIow. If these stations were to be retained it would be advisable to review the choice of the sarnpling period, i.e. advance it from November to September. (iv) From experience gained in recent months it had been possible to say that the continuation of the invertebrate surveillance progremme by OCp staff was possible, provided that the volume of work was not increased and that the staffing level was reinforced' 39. In January and February 1987 national teams with the assistance of a consultant collected fish saroples from riffles in COte d'Ivoire and Ghana, using electro-fishing equipment, with the following objectives: - to determine if riffle fish populations had been modified, by comparing the results with those obtained at the beginning of the Programme in the same stations, - to determine if the R. Pra could serve as an untreated control river to assist in following fish population changes in other rivers which had received farvicide treatment. 40. These surveys had shown that there had been no change in the composition of the riffle fish fauna since 1975176 and that more than 75/. ot the fish of the R. Pra were identical to those found in other rivers which had been under treatment. 4f. The Group was briefed on the steps being taken to make large-sca1e maps of monitoring stations and had the opportunity to examine copies of two recently completed maps; of Danagoro (R. Marahou6) and of Niaka (R. Bandama). When the Harmattan "season" came to an end, and atmospheric visibility improved aerial photographs would be taken of other stations and then used to make appropriate maps. 42. The Group commended the OCP and national hydrobiology teams for their efforts in ensuring a thorough surveillance of the defined monitoring sites over the past year and strongly recommended that: (i) Whenever possible, use be made of OCP air transport to assist in moving the OCP teams to and from the monitoring stations, in order to cut down travelling time and to aIIow the teams more time for devoting to sample analysis and other laboratory activities. (ii) OCP gives careful consideration to the feasibility of moving the base of the OCP hydrobiology teams from Ouagadougou to either Bamako or Bouak6. Such a move would result in increased efficiency in monitoring activities in the original Programme area, would place the teams in closer proximity to the Western Extension and thus improve liaison, and would provide for more continuous contact between the teans and the scientific staff engaged in the testing of new larvicides. (iii) Every effort be made to complete the large-scale mapping of monitoring stations as soon as possible. JPC9.3 (0cP/EAc/88. 1 ) Annex I Page 33 (c) Questions concerning the nonitoring of lotic environnents 43. The Group r{,as presented with a working paper entitled "Questions concerning the nonitoring of lotic environnents in the Onchocerciasis Control Progrnmme" prepared by ORSTOM Hydrobiologist Dr J.M. Elouard. Extracts from the Foreword and Introduction of this document are presented in Appendix ], to serve as a summary of the author's objectives. 44. The Group acknowledged that this was a very inportant document, raising questions and issues which had to be addressed. However, in view of the dimensions and complexities of the subjects covered, the Group considered that there lvas not sufficient time avaitable for a detailed discussion of the document during the current session. Accordingly, the Group recommended that the document be put on the agenda of the next session. 45. After a very brief review of the document, the Group considered that thefollowing two questions concerning major issues, would have to be answered during the next session: (i) Is it possible to extract from the large quantity of existlng surveillance results, information which will alIow us to focus surveillance on certain taxa or certain methods? (This undertaking would need to include the testing of certain synthetic indices such as the Cairns Index). (ii) Can one, in establishing the relationships between the short-term and long-term results, establish predictive models for the evaluation of population densities and structure of populations? E. PROGRAMME ANALYSIS OF AQUATIC MONITORING DATA (a) Data entr-v exploitation 46. A recent development had been the entry and transfornation of all long-term monitoring data in the computer facility at OCP/HQ, Ouagadougou. As a result ofthe implementation of this neh, system, in October 1987, national teans were sent analysed tables of all the data which had been collected in their respective stations and sent to the Programme since the beginning of monitoring activities. 41. Copies of some of the tables, which were presented to the Group comprised: (i) For invertebrates: Tables on the mean number of individuals per Surber and on the mean day-time and night-time drift indices of thedifferent taxa per station for the different sanpling dates. The results had also been grouped according to the principal taxonomic groups. (ii) For fish: Three tlDes of Catch Per Unit Effort (CPUE) table and one type of coefficient of condition table had been prepared: - CPUE per species and per mesh size for each sanpling date, - total CPUE per species for the different sampling dates, - total CPUE per sampling date per nesh sizes, - coefficient of condition for the different sampling dates and per species. JPc9.3 ( 0cP/EAc/88. 1 ) Annex IP"E]4 48. It was noted that various tlpes of analysis could be conducted on the tabulated data and that certain nodifications were now being nade: to improve and adapt the entry programmes to changes made in the monitoring data reporting forms; to facj.litate the preparation of tables and graphs; to increase the rapidity of execution and flexibility of data entry and analysis progrnmmes. 4g. It was also noted that summary graphs of data for previous years, with respect to requested groups of taxa, would be initially provided by the University of Salford for distribution through OCP to national hydrobiology teams. 50. The Group recommended that OCP staff start to prepare an annual summary(data book) of monitoring data. This docunent should be finalized before the end of October 1988 and sent to the national hydrobiology teans to assist them in preparing their reports for the next Annual Meeting of Hydrobiologists. F. INDEPENDENT ANALYSIS OF AQUATIC MONITORING DATA 5L. It was noted that although no independent analysis had been conducted during the past year, a contract proposal had been submitted by the University of Salford to the Programme in accordance with a recommendation of the eighth session of the Group. The proposals consider both the "core" and Western Extension areas and is intended to establish major trends and to define the relative usefulness of the various monitoring stations. Furthermore, since the last analyses for the original Programme area were made more than thro years ago, evaluations of the impact of permethrin and carbosulfan will be included, and it j-s considered likely that useful indicator species will emerge as was the case with other insecticides. 52. The Group recommended that the independent analyses include an evaluation of the Cairns index and other innovati.ve techniques, such as the Fairhurst index, to determine their potential va1ue, and a study of combinations of monitoring stations and insecticide tests to i.mprove the concept of community typing ("finger-printing"). The Group further recommended that the finaf analyses should be made by appropriate staff of OCP and of ORSTOM. 53. The Group noted appreciatively that the ten-year summary of fish sampling data had already been published in "Chemosphere" and a conparable paper on invertebrates was now ready for submission for publication in the same journal. Additional collaborative publications had also been initiated and were currently in preparation. REPORT ON LITERATURE SEARCH ON ENVIRONMEI.ITAL DISTRIBUTION AND FATE OF CARBOSULFAN 54. The Group received from one of its members a presentation on the potential environmental distribution and fate of carbosulfan, based on the linited data available in the open literature. The conclusions drawn which confirm the results of a similar exercise conducted during the eighth session of the Group, were that the possibilities of delayed toxic effects of carbosulfan and its bio- accumulation potential, were both small. G JPc9.3 (0cP/EAc/88. 1 ) Annex I Page 35 55. Several organisms quickly metabolize this pesticide which aLso had a great affinity for suspended solids and sedinents. Moreover, the transient nature ofthe insecticide suggests that the assessment of risk can be developed in terns of its short-tern toxicity, rather than in terms of chronic toxocity. 56. The limited data available on this chenical in aqueous environrnentsindicate that there is a rapid conversion of carbosulfan to carbofuran or other metabolites, mainly by hydrolysis and cleavage of the carbanate N-S bond of the molecule. These observations have been confirned by other published results of studies on the degradation of carbosulfan in soils and terrestrial environnents.Accordingly, a further literature search was initiated on carbofuran which isless toxic to the aquatic fauna than carbosulfa.n. For the carbofuran moleculedissipation patterns are relatively well-defined for neutral and alkaline vraters, provided that hydrolysis is IikeIy to be the dominant degradationprocess. It is not possible to define precisely the kinetics of the process.However, available evidence limits the length of the process to an order of nagnitude measurable in days. 57. Carbosulfan is not expected to accumulate to an appreciable extent in fish, neither from theoretical nor experimental findings. It is therefore suggestedthat attention be given to investigating the ecological responses of thepopulations to the short-term effects of treatments, instead of studying thepotential long-term effects. 58. rt was to be noted that carbofuran has shown high toxicity to mqmmals andbirds. However, under the conditions of field appli-ation this molecule was not expected to produce adverse effects on warm-blooded animals due to the tendencyfor it to be rapidly hydrolysed into less toxic metabolites in neutral and alkaline h,ater. 59. To demonstrate the procedure followed to nake a preriminary hazard assessment for carbosulfan, a paper wilr be prepared, by a Group Member, assembling the existing data on environnental distribution and fate, exposurepotential during pilot treatnents, acute toxicity to African species of fish andthe monitoring of field data on fish and invertebrates. 60. The Group recomnended that close examinations be made of aII data obtainedfrom samples collected from rivers in the Bandama basin which had received short-term treatment with carbosulfan since 1!86. These studies were considered necessary in the light of observations made on changes in a1gal communities,possibly linked with a reduction of grazing invertebrates and the results oftoxicity tests on fish. In addition, the results of community multivariate analyses should be compared with those obtained from long-tern monitoring. It was recorded that the biostatistics team of the University of Salford would bepleased to assist with this work. H. RESEARCH ON NEW LARVICIDES AND FORIT{ULATIONS 6t. During the period under review, comparatively few new larvicides had beenprovided by manufacturing firms for screening by OCP. This was particularlytrue for classicar chemical compounds. rn this group onry a few pyrethroid compounds and about four organophosphate formulations had been received andtested at the laboratory stage and in rivers. JPC9.3(ocPlEAcl88. 1 ) Annex I PaC. 36- 62. On the other hand several B.t. H-14 formulations had been received and tested in gutters. Many of them did not show activity superior to the present operational fornulations or did not meet OCP physical characteristics requirenents. For the benefit of the Group, only those formulations which had gone through the aquatic nonitoring stage of evaluation were given consideration. (a) B.r. H-14 63. It was reported that because of increased competition between B.t. H-14 manufacturers and in view of expected improvenents in cost-effectiveness, the Progrnmme continued to test formulations of the product; especially those provided by the two main manufacturers, Sandoz and Abbott. 54. Two new fornulations had been tested in paralIeI under operational conditions (Sandoz HPD-6000 and Abbott Vectobac 24AS) and were both found to be effective on a dose rate of O.8 ng/L/10', thus permitting a 33/ reduction on the dosage possible with formulations in current usage. However, the physical characterlstics of these two formulatlons must be signiflcantly improved before their operational use can be envisaged. Accordingly, snmples of new inproved fornulations will soon be field-tested and it is hoped that one will be found which has appropriate physical properties and at the sane time, allowing a further dosage reduction to 0.4-0.6 ng/L/LO' for rivers having discharge rates of up to 100m3/s. (b) Pyrethroids 65. The Group was informed that as from 1p8p, only Lh,e 251 EC "Pounce"permethrin from FMC would be used operationally in replacenent of Talcord (from Shell) and Coopex (from Wellcome). The "Pounce" formulation was thought to be slightly less aggressive on some groups of aquatic insects, but was very similar in activity to other permethrin formulations. 66. Most of the pyrethroids that had been tested had shown more or less the sarne levels of efficacy and the sane non-selectivity to other non-target aquatic fauna. Nonetheless efforts were still being made to select one or two possible replacement compounds, should resistance develop to permethrin, even though there was a strong chance of cross-resistance across the board. 67. Therefore, considering the different modes of action or the mechanisms involved, the list of possible replacement candidates had been narrowed down to three: biphenthrin (OMS 3024) (FMC), lambda-cyhalothrin (PP 321) (OMS 3021) ICI, and cyphenothrin (OMS 3032) Sumitomo, all belonging to the alpha cyano methylated biphenyl alcohols group. 68. Although there is no clear-cut evidence for cross-resistance amongst the pyrethroids, it appears from studies made on mosquitoes that resistance to pernethrin does not necessarily induce cross-resistance to biphenothrin, and possibly also not to lanbda-cyhalothin and cyphenothrin. However, it had to be noted that all three of these compounds lrere more toxic to aquatic non-target organisns than permethrin. 69. No further trials with these new pyrethroids have been planned for 1988. However, should resistance to permethrin be detected, the three new pyrethroids would imnediately be checked for resistance and, depending upon the results, one compound would be selected for operational trial, should there be no better alternative. JPC9.3 ( 0cP/EAc/88. 1 ) Annex I Page 37 70. Trough tests on other pyrethroids from Wellcome and Zoecon were inprogress, but none had yet been tested for their toxicity to non-target organisms. (c) Organophosphates: phoxin 7t. Since it had been learnt that Bayer would no longer produce chlorphoxim after 1990, a replacement had been sought, and Bayer had proposed phoxim. Threefornulations of phoxim had been tested: a to/ EC fornulation and two 5ol ECfornulations. The two 501 ECs had shown better activity in trough tests and hadbeen selected for fietd trials. The results of the field trials were not very encouraging; the best formulatlon at a dosage of o. l ng/L/Lo,, was observed tohave a very poor camy. 72. Further tests for a better evaluation of this fornulation h,ere in progress;it is being kept in mind that phoxim does not show cross-resistance withtemephos. Furthernore, at the dosage rate of O.t ng/L/70' its effects on non-target invertebrates appeared to be unacceptabre; at twice that dosage environnental side-effects were unacceptable. (d) 0 !es: Pyraclofos ( oMS 3040) 73. This compound appeared to be more attractive than phoxin and field trials were in progress. If sufficient quantities of the formulated material becameavailable, an operational trial would be conducted during the 1988 wet season. 74. Tests conducted to date had not established cross-resistance of this compound with temephos. However, further cross-resistance trials were i.nprogress along the lower R. Como6 against resistant forest larvae, and along theR. Bafing against resistant savanna larvae. (e) Insect growth regulators 75 0f several growth regulators tested in mini-gutters, the two juvenoidsOMS 3010 (Phenoxycarb 2ofr Ec, MAAG) and oMS 3019 (1of EC, sumitono chemicar) were the only ones which had demonstrated reasonably high activity againstmature S.damnosum s.1. larvae. 76' Phenoxycarb was fully effective against mature S.damnosum s.1. larvae at adosage rate of o.L. ng/L/Lo' . rt will be further teitea aeain"i y"""! larvae and smaIl-scare river trials will eventually be performed. 77. OMS 3019 had been tested in the field at a dosage rate of 0.1 ng/L/2o,.The overall efficacy just below the application point was only 5Ol, increasingto 9Ol 3.5 km downstreem. In view of these discturaging results further triatsare not envisaged, it also being noted that this compound had some adverseeffects on some aquatic invertebrates, e.g. chironomids. (f) Comments by the Ecological Group 78' Ttre Group was pleased to note the promising preliminary results with someof the new fornulations of E !. H-14 and with tf,e nehr organophosphate andpyrethroid compounds. rn vfEilof the great care that was always taken intesting new larvicides, the Group accepted the offer of one of its Menbers toconduct a literature review of the effects on non-target aquatic fauna oflanbda-cyhalothrin, bipenthrin, cSpenothrin and pyraclofos. JPC9.3 (ocP/EAc/88. 1 ) Annex I P"c. 36 79. The Group reaffirmed its concurrence with the Programme's continuing policy to accord the highest priority to the developnent of new alternative larvicides. The objective has been and continues to be, the selection of compounds which must effectively kill the Simulium targets, while producing the least effect on non-target fauna and having the lowest probability for the development of resistance. To this end, the Group advocated a strong programme for the continued testing of alternative larvicides, including a fuII complement of scientific staff, until such time that it had been established that significant reductions in larviciding operations could be made possible because of the use of ivernectin. 80. With regard to priorities for the testing of new formulations of compounds currently in use in OCP and of new compounds, the Group made the following recommendations on priorities: (i) New formulations of B.t. H-14; (ii) Pyraclofos, especially field trials at high discharge rates, assuming that adequate quantities of this compound were nade available to the Progremme for testing before the onset of the 19BB wet season;1 (iii) New pyrethroids which exhibit the lowest probability of developing cross-resistance with permethrin while maintaining minimal effects on non-target fauna; (iv) Insect growth regulators (ICR). 81. The Group also advised that if sufficient quantlties of pyraclofos were not available by the 1988 wet season, it would recomnend that additional tests be conducted with phoxim. I. WORK PROGRAMME FOR 19BB-89 (a) In the initial Programme area 82. The Group recommended that the monitoring of fish and invertebrates in the initial OCP area and in the Southern Extension area be continued at all the stations selected during its eighth session. The factors taken into consideration in naking this recommendation included: the good background information available, extending back over 10 years; the value of these data in terns of interpretation; the variety of river and basin types; the necessity for OCP to continue to use permethrin and carbosulfan in the "coret' area. 1It has subsequently been learnt that the manufacturer does not yet have the formutation facilities to provide the Programme with the 2000 litres which would be required for an operational trial. Further evaluation must therefore be postponed until 1989. JPc9.3 ( 0cP/EAc/88. 1 ) Annex I Page 39 83. Ttre Group acknowledged that there r,vere sone questions about the value of data collected fron monitoring sites on the Black and White Volta rivers in Ghana, because of construction work which could change the character of the sanpling points. However, it was agreed that correction factors could be introduced into the data analyses. In addition, and together with the R. Pru station, these stations were potentially valuable because they were located in, or close to, areas of organophosphate resistance where alternative and nore toxic compounds could be used. 84. Ttre Group also recommended that the sanpling interval for fish in COte d'Ivoire (Rivers Bandama, Cono6 and L6raba) and in Ghana (Rivers Oti and Pru) should be two nonths. Furthermore, that sa.mpling for invertebrates of the Cono6 (Gans6) and the Black Volta (Banboi) should be advanced from November to September. Togo nonitoring sites (Rivers Oti and Amou) should continue to be sampled as at present. 85. Tables 1 and 2 give details of the nonitoring stations and sanpting frequency for studies on fish and on invertebrates, respectively. (b) In the Western Extension Area 86. The Group reconnended that additional nonitoring sites for fish and invertebrates be selected in the Western Extension area, in Senegal and in south-eastern Guinea, and that they be monitored by national hydrobiological teems, once a year during the dry season. Staff of oCP and oRSToM should select these new monitoring sites taking into account their accessibility, representativeness for fish and invertebrate fauna, flooding regime and plans for treatment with larvicides other than temephos and B.t. H-14. The Groupfurther recommended that two consultants, an ichthyologist and an entomologist, be invited to sanple at the nonitoring sites short-listed by OCP and ORSTOM and to propose to the Group those sites considered to be most suitable for yearly surveillance. J. OTHER MATTERS (a) OCP research needs 87. The Group recognized that there were two basic research needs concerning hydroblological data. 88. The first and quite clearly the most urgent was the need for new and innovative analysis of what is a tremendous data bank. Although the hydrobiological data probably represent one of the most extensive sets of such information on fish and invertebrate populations, only minimal s5rnthetic and analytical evaluations have been made. As exanples, it was important to compare a1I the short-term data collected from mini-gutter triaLs with the long-term tests for predicting long-term trends, and to make an analysis of fish and invertebrate communities according to functional feeding group. Furthermore, it was inportant to attempt a classification of the regional fish and invertebrate faunas in terms of their susceptibility to the larvicides used by the OCP. Such a synthesis should be used to determine if laboratory and short-term (mini-gUtter) information on susceptibility can be used to predict effects in thefield on fish and invertebrates. Another example wouLd be the correlation between hydrological patterns and patterns of fish and invertebrate populations, independent of the use of larvicides. C1ear1y, if larviciding has had no effect, such correlations should be quite good. JPC9.3(ocP/EAcl88.1 ) Annex I Pase ItO- 89. The efforts on interpretive analysis which have, to date, been performedlargely by Dr Fairhurst, show considerable progress. The Group recommended most enphatically that these analytical, interpretive and synthetic efforts bySalford University can be significantly expanded and accelerated. To facilitatethis most critical task, it was important that the Salford University tean had access to consultation with key nembers of the oCP and oRSToM concerning the data and their interpretation. 90. The second general need was to focus field research projects in such a waythat they served to clarify critical issues relevant to the first research need; namely innovative analysis of existing data sets and the interpretation of trends and relationships within those data sets. The major research needsfalling within this second category which were identified by the Group in discussion with OCP and ORSTOM staff and which were either on-going or had been proposed by national hydrologists, were: - reproductive periods for dominant fish species, distribution of invertebrate drift, vertically in the water column, and in settling and concentration areas in slow reaches (pools). 97. Some smal1 specific projects had received funding from OCP to encourage relevant independent research by national teams. Others had been proposed and await a decision concerning the availability of personnel and funding. 92, Ttre Group reconmended that, in accordance with the position adopted by the EAC, it was also important to support attempts to obtain research funds fron sources outside OCP, particularly for broad-scale projects of general interest which would address problems relevant to the Progremme in its final years. But, more importantly, such projects would ensure the future use of experienced national scientists in environmental research projects critical to West Africa, after the end of the OCP. Furthermore, the Group pointed out that research funding for projects which came from sources other than OCP would contribute to the international recognition of the Programme and would afford the opportunityto involve scientists not presently related to the OCP effort. 93, Finally, the Group gratefully accepted the offer of one of its Members to report to the tenth session on existing programmes using bivalve molluscs to monitor long-term biological effects of environmental impacts. (b) Ivermectin 94. Dr Fairhurst gave the Group a brief report on the effects of Avermectins on the decomposition of faecal matter. Because of both the scarcity and conflicting nature of the literature encountered so far, the Group recomnended that Dr Fairhurst be asked to extend his search for literature on this subject. K. ARRANGEME}.ITS FOR THE NEXT SESSION (a) Chairnan 95. Ttre Group announced that Dr L6vOque would be the Charinan for the Group's tenth session (1989). Dr L6v6que would also represent the Group at 1988 neetings of the Expert Advisory Committee and the Joint Programme Committee. JPc9.3 ( 0cP/EAc/88. 1 ) Annex I Page 1 (b) Dqte and place of tenth session 96. It was agreed that the tenth session would be held either during the rrreek conmencing 20 February or 1l March 1989, depending upon the availability of members. Preferences should be comnunicated to the Progranne Director as soon as members have had an opportunity to revlew their existing engagements for 1989. 97. A decision on the venue of the tenth session would be taken when moredetails becane available on opportunities for members to visit field activities. 98. The Group recommended that a Hydrobiology workshop be held in 1989,inmediatery prior to the tenth session of the Ecorogicar Group. L. APPROVAL OF THE REPORT 99. Ttre draft report was reviewed before the end of the session and thefinalized version approved by the Charinan. M. CLOSURE OF THE SESSION (a) Address by the Programme Director, Dr E. M. Samba 100. The Director expressed how very much he had appreciated having the opportunity to participate in this session of the Ecological Group. He underlined the importance of the Group to the Programme and thanked the Groupfor its excellent collaboration, for its understanding of Programme requirenents and problems, and for the high levet of its scientific discussions and inputsinto the Programme. The Programne r{ras very grateful to the Group for itsefforts in tailoring environmental monitoring activities to meet progrnmme requirements during the last two years. It was also very obvious ttrat wi.tn tne encouragement of the Group and in collaboration with the OCP Hydrobiologist, national hydrobiology teans had appreciably improved the quality of their monitoring activities and of their reporting. 101. In presenting an overview of the status of the Programme in 1987 and at thepresent time, the Director endorsed the remarks nade by the chief, vectorControl, during his welcoming address to the Group. Turning to the present andimmediate future the Director reiterated that the programme h,as continuing itspolicy of strict financial control in order to retain Donor confidence and toallow Progremme activities to be both expanded and accelerated. In addition,the most encouraging results had been obtained from triars with themicrofilaricide, ivermectin, and there were now good indications that this drugcould soon be used on a large-scare, pararrel with vector controL. LOz. AE the end of his presentation the Director expressed his sincerest thanksto Professor K-W. Cummins, the retiring Chairman, for the excellent way in whichhe had ted the Group during the last three years. He also took the opportunityto congratulate and welcome the chairman-elect, Dr c. L6v6que. (b) Address by the Chairman, Prof. K Irl . Cummins 101. The session was closed by the chairman during the afternoon of4 March 1!88. JPC9.3 ( ocP/EAcl88. 1 ) Annex Ip"E"-IZ 104. In his closing remarks, the Chairman noted with great regret that the ORSTOM Laboratory in Ba-mako would be closed down in 1t88. He reminded the Group of the very important contributions made by ORSTOM personnel to the Progrqmme and recalled that the Group had benefited most significantly from its contact with ORSTOM staff. It was particularly stressed that ORSTOM hydrobiologists had always provided valuable insight into such matters as sampling strategies, the interpretation'of monitoring data, and specific environmental tests of larvicides. 105. The Chairman expressed his gratitude to the French-speaking participants for their very serious efforts with the English language which had enabled the session to be conducted in Eng1ish, thus avoiding the expense of having toprovide simultaneous interpretation facilities. 106. Fina11y, the Chairman thanked Mr B. Nango, Mrs M. Coulibaly and Miss Nignanfor providing valuable administrative and secretarial support. TABLE l: FISH I,|0NIT0RING STATI0NS RETAIilED AND THEIR SAilpLIt{G FREQUENCY, lgBB/89 ri ver/stati on JPC9.3 ( 0cP/EAc/88. 1 ) Annex I P.s;13 Sampling frequency Every 2 months Every 2 months Every 2 months Every 2 nonths Every 2 months Every 2 months Every 2 months Every 2 months To be established after selection of sites- l{ap Reference IC6te d'Ivoire Bandama - iliaka Comoe - Gans6 Leraba - pont Routier Ghana Oti - Sabari Pru - Asubende Gui nea Sankarani - l{andiana Dion - Baranama l{al i BaouIE - l{issira Coastal Guinea/Sierra Leone 8 7 6 5 4 l3 12 I I l{aps I and 2. JPC9.3 (ocP/EACl88. 1 ) Annex I Pa#-I4 CARTE 1: POSTES DE SURVE!LLANCE DANS L'AIRE OPERATIONNELLE OCCIDENTALE, 1988 _ 1989 1 R t t c1. MAI ArAXO I I x ITA \ 2 o I)r GU R II o IAN ( R \ I R RR ( I I 8 FA R R I ( \ I I BOBO{IO( LASSO a R I\ I XilI )i a RI v'I I ooorENNE !EYLA L t o I \ ctvR o BO('AXE 0 ro R Y RESISTANCE AU TEMEPHOSCHEZ LES VECTEUBSSAVANICOLES LIB I ,\ ( \ I t I , I o loo too4 la ABIDJAI{ wHo Eon2t l , \ TABLE 2: INVERTEBRATE I,IONITORING STATIONS RETATNED Ar{D THEIR SAilPLTNG FREQUEI{CY, 1988/89 Country/ri ver/stati on 1{ap Reference C6te d'Ivoire Como6 - Gans6 Sampling frequency JPc9.3(ocPlEAc/88.1) Annex I P"c;15 Once a nnnth, September to January Every 2 weeks, l{overber to January 0nce a month, February to Apri I 0nce a month, September to January Every 2 weeks, l{ovember to January 0nce a month, February to April 0nce a month, June to December Every 2 weeks, l{ovember to January 0nce a month, February to Apri I To be established after selection of sites. 7 Bandama - Niaka l{arahouG - Danangoro l,larahouE - Entomokro Ghana Black Volta - Bamboi Guinea Niandan - Sassambaya ilal i Bakoye - Kokofata Togo Amou-Amou-0blo Coastal Guinea/Sierra Leone I 9 l0 I4 (i ) (ii ) (i ) (ii ) il 3 2 (i ) (ii ) I ilaps I and 2. I ) ) ) ) JPC9.3 (ocPlEAC/88.1 ) Annex I P"d-I6 wHo Nn20 TAP 2: IIONITORING STATIONS IN THE EASTERX oPERATTOxAL AREA, tgtt/89 I I I NIG f XARA r3 I I I BFA R o t - - -/t a I I .) XANOI BE O TAXALE -fz- -- - I GHA R R R lt OUA GAOO UGOIJ o R I I I I I 12 PARAXOU o I t I I \ I I NIE t4 t.,T ) I \ \ I I I I OG 3 xUIASI \ \ -1 I COTONOU LOME ACCRA o loo 200 an I ltl TEMEPHOS RESISTANCE IN SAVANNA VECTORS R \ t JPc9.3 (oCP/EAo/BB. 1 ) Annex I F.c.-I7 Appendix 1 LIST OF PARTICIPANTS Members Professor D. calanari, rnstitute of Agricultural Entomolory, Faculty ofAgriculture, University of Mi1an, via celoria 2, 21LJJ Milan, ituty Professor K.W. Cumnins (Chairman), Appalachian Environmental Laboratory,University of Maryland, Frostburg, MD 27532, USA Dr H. De rongh, Haskoning, Berg en Dalseweg 81, 55oo AD Nijmegen, Netherlands Dr C. L6v0que, Directeur de Recherches, Museum national drHistoire naturelle,Laboratoire d'Ichtyologie, 43 rue Cuvier, 75OO5 paris, France Dr M. Yasuno, Chief of Aquatic Ecology, National Institute for EnvironmentalStudies, Onogawa, Tsukuba, 305 Japan other Participants Dr J.M. Erouard, charg6 de Recherches, Laboratoire d'Hydrobiologie, oRSToM,B.P. 2528, Bamako, Mali Dr C.P. Fairhurst, Department of Biological Sciences, University of Salford,Salford M5 4W1, England Dr D. Paugy, charg6 de Recherches, Laboratoire d'Hydrobiologie, oRSToM,B.P. 2528, Bamako 0bserver Dr Margaret A. Wilzbach, Assistant Professor, Appalachian EnvironmentalLaboratory, University of Mary1and, Frostburg, MD 21532, USA Sec ariat Dr D. Bardry (Secretary), vcu/ocp, B.p. !4!, ouagadougou, Burkina FasoDr J. Grunewald, VCU/OCP, B.p. 2279, BnmakoDr P. Guiller, VCU/OCP, B.p . 2279, BarE6- Mr M. H. 0cran, Vcu/Ocp, B. p. 1474 , B;u46, COre d, IvoireDr B. Philippon, Chief VCU/OCP, B.p. 2279, BanakoDr E.M. Samba, Director OCp, B.p. 549, Ouasado,rgpuDr A. S6k6teli, VCU/OCP, B.p. ZZ7g, Aanako Mr L. Yam6ogo, VCU/OCP, B.p. 549, Ouag;dougou JPc9.3 ( ocP/EAclBB. 1 ) Annex I eaEer+B- Appendix 2 MEASURES BEING TAKEN BY OCP/VCU TO IMPROVE TTIE MANAGEMENT OF VECTOR CONTROL OPERATIONS 1. To slow down the development of temephos resistance During the dry season B.t. H-14 is used throughout the Programme area. With the most recent operational formulations, B.t. tt-14 is more cost-effective than temephos for treating rivers with discha.ge .ate" below 25n3/s. At higher discharge rates tenephos is more cost-effective, and it is used as long as possible while susceptibility 1eve1s remain unchanged. The practice of making selective larvicide treatments against susceptible savanna species which were breeding together with resistant non-vector species has been discontinued. At very high river discharges (more than lOOm3/s) permethrin can be usedfor short periods of time because: it is more cost-effective than temephos, vectors resistant to temephos have increased susceptibility to permethrin. 2. To maintain Eood levels of vector control once resistance has developed Once resistance to temephos has developed, chlorphoxim is the replacement larvicide of choice, provided river discharge rates are between 2l and 6O-7On3/s. Above the latter level, it is replaced by permethrin and/or carbosulfan. Because of the wide use of pyrethroids in agriculture, permethrin is not used for treating rivers flowing through cotton-growing areas. In view of the rapid development of pyrethroid resistance in other insects, OCP never uses permethrin for more than six consective treatment cycles. Carbosulfan is a costly larvicide, and, a full evaluation of its environmental impact has not yet been completed. Accordingly, carbosulfan is only used in areas where it is not possible to use permethrin for the treatment of rivers with moderate wet season discharge rates. In other situations carbosulfan is used in alternation with permethrin and/or chlorphoxim when it is not possible to use B.t. H-14 for long periods of time. 3 To minimize the side-effects of larvicide treatments For 6-8 months of the year Bost of the Programme area is under treatment with B.t. H-14. The use of other compounds as replacements for temephos is always confined to the nain stretches of rivers; headwaters and sma1l tributaries are always treated with B.t. H-14. As far as possible, when the main river stretches are treated with B.t. H-14, applications are started before the tributaries stop flowing, to allow the main stretches to be recolonized by non-target organisms from the tributaries. 4JPc9.3 ( 0cP/EAc/88. 1 ) Annex I P"d-49 Appendix 2 Larvicide treatments are suspended as often as possible, especially during periods of flash floods. The maximum used of teletransmitted hydrological data now aLlows larvicide dosages to be calculated very accurately, thus avoiding over-dosing. To improve cost-effectiveness and to ninimize the side-effects of Iarviciding operations 4.1 Bv sreater accuracv of applied dosaEes The Progranme has installed a teletransmission hydrological network which currently utilizes l8 Argos transmitters, this number will soon be increasedto 78. In addition, OCP staff benefit from information transmitted through another network (Hydroniger Project). liith these facilities, river discharge rates can be measured at any time,permitting accurate dosage adjustnents during the course of a treatment cyc1e.In addition, a cotttputer model of discharge precision is now under development. The optinal use of teletransmitted hydrological data results in the avoidance of under-dosing, which could otherwise help induce resistance and which is ineffective in any case. It also prevents over-dosing which is both costry and potentiarly detrimental to the environment. Furthermore, the teletransmission equipnent mal<es it possible to monitor precisely dischargefluctuations, and thus to suspend treatments as flash floods arrive, and at theheight of the wet season. Finally, the application of very precise dosages results in more effective treatnents, which in turn allow more frequent suspensions, especially during the hret season. 4.2 tter use of larvi Hydrological and entomological studies on the behaviour and action oflarvicides in running water have been undertaken (dispersal and carry oflarvicides in ldater, mode of action of larvicides on blackfly larvae, etc). As a result, a more precise relationship between river discharge and larvicide carry can nor4, be established for the five larvicides currently in use. Computer models are now under development for determlning optimal dosages and points of application according to river discharge, the distribution ofblackfly breeding sites and cost parameters. One such model was successfully tested during the 1987 wet season and demonstrated a very significant reductionin the quantities of larvicide applied and the costs of the applications. tf JPCa.3 ( 0cP/EAc/88. 1 ) Annex I Page !0 Appendix 3 EXTRACTS FROM XQUESTIONS CONCERNING THE MONITORING OF LOTIC EI.IVIRONMEI.ITS IN THE ONCHOCERCIASIS CONTROL PROGRAMME" BY DR J. M. ELOUARD Foreword (i) The Onchocerciasis Control Programme has evolved greatly since its beginning. This evolution concerns not only the insecticides employed and the logistics for their application but also knowledge of the vectors. It follows from this that the present strategy for the spraying of the different insecticides is very far from that used at the start of the Progrsmme. (ii ) The sane applies to the monitoring of the watercourses. Ttre achievements are many from the viewpoint not only of methodology and taxonomy of the insects but also of biological knowledge of the environments. ( 11r_ ) The monitoring has, of course, been adjusted every year to new OCP strategies. It has been a matter of adjustments or improvements. However, with the passing of time and the achievements, there should be a more in-depth review of the monitoring in order, on the one hand, to highlight its positive aspects and, on the other hand, make up for the shortcomings. ( iv) This very general questionnaire is therefore a reflection paper being distributed to all those involved in monitoring (national teams, 0RSTOM, 0CP, Ecological Group). The objective is that they would answer if not aII then at least the part concerning their field of competence. A synthesis of the different views and trends could then be prepared in a form that has not yet been established. Introduction (i) After 1l years of biological monitoring of the watercourses treated with antisimuliid insecticides within the framework of the Onchocerciasis Control Programme, a review of the results obtained seems to us to be necessary. This appears to be all the more essential since, on the one hand, the river treatment stategy has evolved in 13 years and, on the other hand, OCP is extending its activities to nev, areas which must be monitored. It wil1, perhaps, become necessary to reformulate the objectives and reflect on possible changes to be made as regards the future strategy, network and methods for the monitoring. (ii) The author had tried to formulate the problems of monitoring in a general frnmework which we would like to be quite broad. Many of these problems have been studied sometimes explicitly but often implicitly by OCP. The point here is to establish what an ideal monitoring is, list the problems and difficulties and then examine the solutions which have been or are to be adopted in regard to the ecological monitoring of the rivers treated with antisimuliid insecticides by OCP. The list of questions is open since the author does not claim to have compiled all the problems related to an ideal monitoring. We hope, therefore, that others will contribute to making it complete. (iii)