Onchocerciasis prevalence in previously known foci in western Uganda: results from a preliminary survey in Kabarole district.

A prevalence survey of onchoceriasis was done in Kabarole district, Uganda, in 1990. The objective was to determine the prevalence of onchocerciasis among communities living in previously known foci. A total number of 1186 persons was included in the study. The infection rate among the communities studied ranged from 0% to 67%. The most frequent clinical signs and symptoms of onchocerciasis were: pruritus (80%), rough skin (46%), skin rash (30%), leopard skin (6%) and sclerosing keratitis (7%). 3.6% of all cases with onchocercasis were found to have no perception of light. The total number of cases in the district was estimated to be 32,000. The study showed that the foci, where Simulium neavei is the vector, are still active. In contrast, very few infections with Onchocerca volvulus were found in the Rwenzori focus, where S. damnosum s. 1. was the vector. The results indicate that onchocerciasis is of public health importance in Kabarole district and needs to be controlled.