A longitudinal study of endemic urinary schistosomiasis in a small East African community.

Urological abnormalities caused by Schistosoma haematobium are apparently common in East, West and Central Africa. A community of 1074 persons living in an area of endemic urinary schistosomiasis in rural Zanzibar, Tanzania, was studied for 2 years to determine the importance of these abnormalities and how they affected patients' health.Of the total community, 1004 persons (93.5%) were examined and the over-all prevalence of infection with S. haematobium was 65.1% and infection rates of the order of 90%-100% were found in subjects aged between 7 and 17 years. The pattern of infection in the community is described in detail; clinical examination was essentially negative, except that a high prevalence (35.4%) of urological abnormalities was found in 794 satisfactory urograms.During the 2-year observation period, 22 persons died and 4 of the deaths were attributed to kidney disease caused by S. haematobium. An unsuccessful attempt was made to eradicate urinary schistosomiasis in the community. The over-all prevalence of infection was reduced to 45.0% but there was no reduction in the prevalence of urological abnormalities. Radiologically non-functioning kidney was inc iminated on statistical evidence as a cause of death. Serious urological pathology was much more common in males than in females.Urinary schistosomiasis in Zanzibar is not a chronic debilitating disease nor is it primarily important as a cause of morbidity but rather because it causes deaths among persons apparently in good health.