A multidisciplinary study of onchocerciasis in Bure area, Ethiopia

A clinicoepidemiological and entomological study of onchocerciasis was conducted in Bure area, Illubabor Administrative Region, in October 1987. All 1063 houses in four villages were numbered and census taken. The total population was 4119. Of the total 1063 houses, 107 (10.07%) were selected by systematic random sampling and all members of these households were examined. History, physical examination, and skin biopsy were taken. Of 4119 people in the area, 3555 (86.3%) were indigenous and 564 (13.7%) settlers. Four hundred and three of the former and 68 of the latter were studied. Clinical manifestations were mild and ocular onchocerciasis was not encountered. One hundred and sixteen (24.6%) had O. volvulus in the skin; with a mean of 11.7 microfilariae per milligram of skin. Positivity in males was 1 1/2 times that in females. None of the settlers had positive skin snips. We concluded that onchocerciasis is hypoendemic in Bure area with mild clinical manifestations. Adult and aquatic stages of Simulium were collected for later identification, and a preliminary report indicates that S. damnosum s.l. is the most likely vector.