The relevance of schistosomiasis for public health.

This paper reviews the impact of schistosomiasis on public health and weighs the results against experiences with new control methods in subsaharan Africa. Good short-term results have been obtained with large-scale population-oriented chemotherapy, but long-term sustainability is dubious due to rapid reinfection, high costs, and low compatibility with existing, often inadequate health structures. Infection control per se is therefore considered unrealistic. For the control of symptomatic morbidity, such as dysenteric syndromes and haematuria, the improvement of basic curative health services should be the first and perhaps only measure. Cases of more serious, chronic morbidity are infrequent in many endemic areas and their prevention through population-oriented chemotherapy would be very costly, whereas good curative care may prevent most of such cases as well. If necessary, supplementary interventions should really be aimed at serious pathology; one treatment in older adolescents might then be as effective as repeated treatments in young children. In a limited number of areas, overwhelming morbidity leads to emergency situations in which mass chemotherapy may be a justifiable short-term intervention.