ECOLOGY OF SCHISTOSOME TRANSMISSION FOCI

Abstract

The study of cercarial populations in the field can provide a useful means of locating schistosome transmission foci and of evaluating the success of bilharziasis control programs. It also provides a means of learning about certain aspects of transmission that have hitherto been neglected. In recent years 6 techniques have been sucessfully field-tested or employed in field research on the biology of the cercarial stage of schistosomes. They include several variations of paper filtration of the water, the use of phototaxy for separating cercariae from water, and bioassay by exposing mice to infective water. The various advantages and disadvantages of each method are discussed in this paper. It is suggested that an approach to the ideal cercariometic method may be achieved by combining a paper filbration technique with mouse exposure.