Assessment of the Infection Rate of Onchocerciasis Inthe Resettled and Indigenous Communities of Asossa,western Ethiopia

Abstract

An attempt was made to determine the infection rate of onchocerciasis in the resettled and indigenous communities of Asossa. A total of 931 persons consisting of 548 settlers and 383 indigenous population, aged five years and over were examined parasitologically for the presence of Onchocerca microfilaria in a skin snip, and 11.1% of the resettled population and 31.3% of the indigenous population were found infected with the parasite. The total mean number of microfilariae per mg of skin snip at the buttock was 15.3. The clinical manifestations recorded include skin atrophy, skin depigmentation, pruritus and presence of nodules at a rate of 15.5%, 20.4%,44.8%, and 1.7%, respectively, among the positives. No visual impairment difference between the positives and negatives was seen and blindness due to onchocerciasis was not detected. Blackfly collection and identification around the near-by rivers indicated the presence of the anthropophilic vector Simulium damnosum s.l. The results recorded for the resettled communities clearly indicated disease propagation in the resettled population who came from areas of the country non-endemic for onchocerciasis in 1984