Report of mission: APOC long term impact assessment of site 1, Nigeria (entomology), 10 - 30th August 1998

REPORT OF MISSION APOC LONG TERM IMPACT ASSESSMENT OF SITE 1, NIGERIA (ENTOMOLOGY) (10 - 30th August 1998) Michael D. Wilson Ph.D. Noguchi Memorial lnstitute for Medica! Research University of Ghana P.O. Box LG 581 Legon, Ghana Tel: 233 21 500374 Fax: 233 21 502182 e-mail : noguchi@ncs.com.gh 1. ltinerary The summary of activities including travel is listed below Date 10.08.98 11.08.98 12-18.08.98 19.08.98 20.08.98 21.08.98 22.08.98 23-25.08.98 26.08.98 27.08.98 28.08.98 39.08.98 Description of activities Departure Accra - arrival Lagos Visit and meeting with WHO personnel at WR office, Lagos Meeting with National NOTF Coordinator and his assistant Dr. Jiya and Saka, administrative, purchase of material needed? Departure Lagos - arrival Calabar Departure Calabar -lkom (Cross River State) Fieldwork commences at the Site 1 - prospection of nearby rivers - trial fly catches at points and selection of the most suitable) - recruitment and training of village fly catchers Regular fly catches and dissections and training of local staff Departure lkom - arrival Calabar Departure Calabar - arrival Port Harcourt Departure Port Harcourt - arrival Lagos Departure Lagos - arrival Accra 2. Introduction and Aim of Mission The mission is one of many to obtain baseline information that is required for the long term impact of CDTI in APOC countries. ln addition to baseline entomological data, sociological and clinical data were also to be obtained. The selected site in Nigeria for the present mission is located in the lkom LGA area, Cross River State (see Table 1 for names of villages and grid reference). 3. Geography of Study Area 4. Scientific Report An initial prospection of rivers in the site area was carried out by the Team on the first day. Two of the three major rivers that drain the area are small and most probably dry out in the dry season. The largest R. Lewa, is likely to be perennial and runs between two of the three selected villages i.e. Etipke and Nkonfap and therefore found to be ideal. The typical breeding site of white water was not observed although we were informed that a water fall exist on R. Nwang located approximately 15 km away. The impression was that swift current and overhanging vegetation was responsible for production of flies in the area. Trial catches of flies were carried out at two points on R. Lewa and the selected catching point is situated downstream of the roadbridge. Regular catches were carried out over a period of 3 days. A total of 401flies were caught over the period, and 384 were dissected out of which 266 were parous (i.e. 69.3% parous rate). The parous and nulliparous flies of each day were then preserved in absolute alcohol in separate tubes. The next stage of the staining and dissecting of flies for infections in the laboratory was not carried out due to the limitations of time and lack of reagents and equipment. This phase of the study will be carried out during the next visit of the Temporary Advisor. On the last day, rivers in the area were prospected and larvae of Simulium damnosum s.l. obtained were preserved in carnoy solution for cytotaxonomic identification. 5. Training Three Nigerian technicians and village fly-catchers were initially trained to recognize the fly and the art of fly catching. Then the entomologist-technician was taken through the process of recording and completing the OCP forms of fly catches (Fiche 1), fly dissection (Fiche 2A) and of summary of results (Fiches 3 and 4). The major part of the period however, was spent in training them to be competent in separating parous and nulliparous flies. The training on staining and dissection was not carried out due to the reasons given above. Prospection of rivers were carried out and the local staff were taught to identify suitable sites for finding the pre-adult stages of S. damnosum s.1., distinguishing them from other Simulium spp. and methods for preserving for cytotaxonomy. 6. Other Observations The initial informed observations was that more than one species of S. damnosum complex might be responsible for onchocerciasis transmission in the area. Simulium yahense and S. squamosum and most likely 'savanna' species do occur in the area. tThe local staff were found to be competent enough to carry out all aspects of fieldwork and therefore should be in a position continue with the field data collection at Site 1. 7. Recommendations o A second visit by the WHO-APOC entomologist is now imperative to continue with the training and monitoring of entomological activiities. o ln view of the experience gained a much more comprehensive list of materials that will be required by the entomology team has been prepared (see Apendix 1). The quantities should be determined by the local Team and also should depend on the work load eg numbers of flies etc.. . The lkom local government area (LGA) is widely known for its Game and wildlife. This was evident from the abundance of 'bushmeat'at restaurants and markets. lt is very likely that Onchocerca species of animal origin is also being transmitted by the local vectors. This has obvious implications, if entomological indices of transmission is to be used to assess the impact of ivermectin treatment lt is recommended that as much of the infective larvae that are found during dissections are preserved for further studies (morphology and molecular). This observation and recommendation should be considered for all the other sites in APOC where impact assessment is being carried out. 8. Personnel o Dr. tMichael D. Wilson, WHO-APOC Advisor Entomologist . Professor B.E.B. Nwoke, Local Entomologist . Mr. Asuquo O. Ekwe, Entomologist-Technician . [Vlr. lnyang Ating, Asst. Entomologist-Technician o Mr. Oyo Efa, Asst. Entomologist-Technician (supervised of fly catches) . [Vlr. Cletus Ekpen, Fly catcher (recruited locally) . [Vlr. Benjamin Njol, Fly catcher (recruited locally) Appendix I List of Equipment, Materials, Reagents and Expendable 1. Laboratory Analysis Compound [Vicroscope Dissecting Microscope (WILD M5, Mag. upto 500x) with external light source Extra bulbs for microscope Voltage regulator for microscope Refrigerator Dissection kit Bottles (100m1, 250m1, 500m1) Universal bottle Bijou bottles lVicroscope slides Microscope cover slips Petri dish [\4icrotitre plates Mayers Haemalum Acetic acid, Glacial Absolute alcohol Chloroform Glycerol Distilled water Nail varnish (neutral) Filter paper 2. Fieldwork Generator 15 amp fused plugs Adapters Electrical cable with lamp holders Bulbs for general lighting (60 Watts) Portable gas cooker + extra gas cylinder Cooking utensils, plastic cups and plates Cutlery Cups and plates Plastic buckets Waste paper basket Jerry cans (water and fuel) Campbeds with support for mosquito nets Mosquito nets Collapsible tables Collapsible chairs lce chest Appendix I (continued) Freezer packs First Aid kit Flashlight + batteries Cutlass Towels and Napkins (cotton) Powdered soap Toilet soap Fly catching tubes (OCP type) Universal bottles (20m1, glass) Bijou bottles (5m1, glass) Cotton wool A4 Paper OCP Forms 1-4 Rubber bands Cellotape Stapler + pins Paper clips Erasers Pencils and pens Carbon paper Files Paper punch Polythene bags