The status of human onchocerciasis in the Kainji reservoir basin areas 20 years after the impoundment of the lake.

A study was made in January 1985 to assess the post-impoundment status of onchocerciasis around the man-made Lake of Kainji, Nigeria, about 20 years after the formation of the lake. The overall prevalence of the infection in the 13 major villages surveyed was 28.5%. The endemicity of onchocerciasis was sporadic (less than 10%) in three of these villages, low (10-39%) in six and medium (40-69%) in four. Although the available pre-impoundment data is inadequate to make a definite conclusion of the impact of the lake formation on the status of onchocerciasis in the area, it is apparent that here, as in most other parts of the country, the prevalence, manifestations, complications and public health significance of onchocerciasis justify the ongoing campaign for the urgent implementation of a nation-wide onchocerciasis control programme in Nigeria.