OBSERVATIONS ON THE POPULATION DYNAMICS OF SNAIL HOSTS FOR SCHISTOSOMES IN THE DELTA OF THE SENEGAL RIVER BASIN

Abstract

Between 1987 and 1990, snail surveys were carried out in the Senegal River Basin at Lampsar, in a natural ‘marigot’, and at Richard Toll, in an irrigation canal. Lymnaea natalensis. Bulinus guernet^* and B.forskalii, were regularly found at both the sites. Bulinus globosus/jousseaumei and B. umbilicatus were only present at Lampsar. A decrease of the snail density was observed during the rainy season at Lampsar. The recent appearance of Biomphalaria pfeifferi at Richard Toll is discussed. The data show that adult B. pfeiffert are present in the main irrigation canal all through the year. Consequently parasite transmission will be possible throughout the year as well.