Comments on the epidemiology and control of bilharziasis.

This article attempts to outline the basic principles to be considered in schistosome-control. The authors draw attention to the desirability of placing in perspective the various aspects of the problem: sanitation, human therapy, and the role of intermediate and reservoir hosts. The difficulties inherent in each of these approaches in different endemic areas are discussed-in particular, the obstacles to successful restriction of the snail populations concerned in transmission of the parasites. Emphasizing the need for further studies in molluscan bionomics and ecology, and investigation of new molluscicides and new drugs, the authors suggest future campaign methods involving a combination of sanitary control, prevention of exposure to cercariae, control of snail hosts, and chemotherapeutic measures.