Should nutrition be considered as a supplementary measure in schistosomiasis control?

The most important data on the relationships between nutritional status and schistosomiasis mansoni are reviewed. The probable impact of such findings on the traditional strategies for control of the disease are discussed. In endemic areas, malnutrition and schistosomiasis seem to be associated. Malnutrition impairs the biological development of the parasite. However, like the parasite, it also depresses the host's immune system, and malnutrition and infection can be mutually aggravating. Recent schistosomiasis-control activities, although apparently well designed, have frequently seemed ineffective because of the multiplicity of factors involved, and have not offered a realistic promise of sustainable and definitive control. However, these actions must be continued and even encouraged because they do lead to reductions in the prevalence of infection and, of particular importance, to reductions in the incidence of the more severe forms of the disease. Improvement of the nutritional status of those who inhabit endemic areas, particularly those on low incomes (who are at relatively high risk of malnutrition and of schistosomiasis), is recommended as a supplementary measure.