The Relation of Physiography to the Types of Freshwater Environments and the Presence of Australorbis Glabratus in Puerto Rico

Abstract

In Puerto Rico, Australorbis glabratus is considered the sole vector of Schistosoma mansoni. The irregular distribution of this snail and of schistosomiasis presents problems of an ecological nature which require a comparative approach for their solution. In April, 1953, surveys were started directed toward determining the types of freshwater environments present, their physical, chemical and biotic characteristics, and to consider what effect these might have on the transmission of schistosomiasis. While much has been published on the distribution of schistosomiasis in Puerto Rico, the climate, and topography of the island, there has been little correlation of these factors and their possible relationship to the epidemiology of the disease. Hoffman (1927), Hoffman and Faust (1934) and Faust et al. (1934) discussed the general incidence in man, and initiated studies on the biology of the snail and ecology of freshwater habitats. The last two, unfortunately, have received little attention since this early work.