Daily and weekly injections of sodium antimony dimercaptosuccinate (TWSb) in the treatment of Schistosoma haematobium infection: with particular reference to the intensity of infection.

With a view to developing a schedule for the ambulatory treatment of Schistosoma haematobium infection with sodium antimony dimercaptosuccinate (TWSb), a trial was conducted in Tanzania of the comparative effectiveness of daily and weekly injections of TWSb in schoolchildren. In-patients received five daily injections of 6 mg/kg, and out-patients the same total amount in five weekly injections.It was found that the two schedules were equally effective, and that, while the cure rate varied inversely with the intensity of infection as assessed by egg output, the reduction in egg output of groups of patients was reasonably constant regardless of the initial egg load.The author suggests that in the evaluation of drugs for schistosomal infection regard should be had to the intensity of infection and that the percentage reduction in egg output should be investigated as an additional index of therapeutic effectiveness.