Schistosomiasis in the Gumara and Ribb irrigation project area, Ethiopia.

A survey of intestinal schistosomiasis and vector snails was conducted in the Gumara and Ribb Irrigation project located on the eastern side of Lake Tana, northwest Ethiopia. Within the project area, stool specimens from 1273 people were examined by the thick smear method. The average infection rate for Schistosoma mansoni was 1.6%. Two localities, Addis Zemen and Yifag, located just outside the project area, were also examined, the former showing an S. mansoni prevalence of 34% (75/223) and the latter 18% (18/101) among school children. In Debre Tabor, the provincial capital 50 km away from the project site at an altitude of 2800 m., five S. mansoni cases were found among 111 school children, but they were considered to be imported cases. The possible establishment of intestinal schistosomiasis in the project area is discussed.