Chemotherapy in the control of urinary schistosomiasis in Nigeria.

Praziquantel (Biltricide, Bayer AG), which has been found to be very effective in the treatment of schistosomiasis, was evaluated to formulate the minimal cost-effective dose in selective chemotherapy of 135 school children aged 6-15 years. Side effects were minimal. The drug had no effect on the heavy load of intestinal helminths found in 78.1% of the subjects. However, it cleared the urinary schistosomiasis in all but 0.9% of the subjects at the dosages used and after 18 months only 0.59% of the entire school population had new infections. The targetted chemotherapy reduced the prevalence rate from 16.0% to 0.59%. The lowest dose of 1 X 20 mg/kg body weight was able to clear the light infections of 52 subjects. This has a great economic advantage because the drug is expensive and most of the infections in Nigeria are light to moderate.