clinical manifestations of mesoendemic onchocerciasis in an area with multiple filarial species

background : the imo river basin, nigeria is endemic for onchocerciasis, bancroftian filariasis, loaiasis and mansonellosis. this study was aimed at determining the clinical manifestations of onchocerciasis in this region. methods: a cross-sectional study was carried out in 2006 in umuowaibu i and ndiorji commu­nities in okigwe local government area of imo state, nigeria. consenting individuals were ex­amined for various gradations of skin manifestations, subcutaneous nodules, and visual im­pair­ments by qualified medical doctors. five categories of skin manifestations were observed, namely permanent itching, onchodermatitis, atrophy of skin, leopard skin, and sowda. a total of 1024 individuals were examined. results: the prevalence of the skin manifestations were permanent itching (2.5%), onchoder­ma­titis (3.9%), atrophy of the skin (5.8%), leopard skin (22.1%), and sowda (0.1%). the preva­lence of subcutaneous nodules was 25.3%, but 88.9% among the oldest age group, and mostly found in lower half of body. the majority of cases of visual acuity problems (6.8% overall prev­alence) were in the oldest age groups. among those who were ≥ 20 years old, the prevalence of visual acuity problems was significantly higher in females than in males (χ 2 -test; p < 0.05). only two of the examined persons were observed to be blind. conclusion: clinical manifestations of onchocerciasis are perhaps more intense in the area prob­ably because of presence of endemic infections of other filarial species.