Haematobium schistosomiasis among seminomadic and agricultural Afar in Ethiopia.

Parasitological and malacological surveys were made in the Afar tribal area on the flood plains of the Awash River. S. haematobium--infections are most prevalent among seminomadic Afar living around the swamps and lakes in the middle part of the Awash Valley. Infection rates between 6 and 52% were found among seminomadic Afar and between 0 and 27% in agricultural groups. The highly localised distribution of vesical schistosomiasis is maintained by the distribution of the swamps, lakes and the human population and by migration patterns. On the marshy plain near Gewani significantly higher infection rates occur among Afar females than males. This is apparently due to sex differences in water contact patterns.