The epidemiology of onchocerciasis in the resettled and indigenous population in Pawe, western Ethiopia

A survey to determine the prevalence of onchocerciasis in a sample populati on aged 5 years and over was made in Pawe, western Ethiopia. A total of 986 persons (636 settlers and 350 indigen) were examined for parasitological ( in a skin snip) and clinical manifestations, of which 310 (27.8% settlers a nd 38.6% indegenous) were found infected with Onchocerca volvulus. Apart fr om itching and associated acute papular eruption the following signs in the skin and lymphatic system were recorded:- skin artrophy, skin depigmentati on, and presence of nodules. Blindness due to onchocerciasis has not been a ssessed. The entomological investigation through larval and adult collectio n and identification showed the presence of the anthropophilic vector speci es Simulium damnosum s.l. Out of the 111 adult black flies caught, 65 parou s flies were identified and dissected for the presence of microfilariae. On e fly was found positive for L-2 stage and 3 flies were positive for L-3 st age giving 5% of the dissected flies positive for infection with O. volvulu s. The results obtained in this study indicate the need for an immediate co ntrol measure.