Endemicity and clinical manifestations of onchocerciasis in the province of Bururi, Burundi

A sample of the population of 20 'collines' (administrative units) of the province of Bururi (Burundi, Central Africa) was examined to determine the prevalence and intensity of onchocerciasis in this endemic region. In all, 34.4% of the population is infected, that is about 80 000 people for the whole area. Around Rumonge onchocerciasis is hyperendemic. This area is surrounded by a mesoendemic zone and at the periphery onchocerciasis is hypoendemic. The clinical examination of a subsample showed that pruritus and skin lesions are not very frequent (58.2 and 28.1% respectively in positive persons). Subcutaneous nodules are small and difficult to find (21.3% in positive cases). Vision is 10/10 in 92.2% of the examined eyes. A slight drop in visual acuity may be attributed to onchocerciasis in 9.4% of positive cases.