Thumbnail of Yearly efficacy of drug therapy. Results of praziquantel treatment (solid bars) or metrifonate treatment (shaded bars) for Schistosoma haematobium infection in the Msambweni area during 1984 to 1992. Cure rates (conversion from egg-positive to egg-negative urine in annual follow-up testing) are shown for all egg-positive cases, by year of treatment. Only metrifonate therapy was given in 1987, and no treatment was given in 1988.