BIOLOGICAL-CONTROL OF SCHISTOSOME TRANSMISSION IN FLOWING WATER HABITATS

Marisa cornuaretis was evaluated in Puerto Rico for control of schistosome transmission in flowing water. A population of Biomphalaria glabrata and their schistosome infections disappeared after introduction of 20,000 M. cornuarietis to an endemic stream, while in nearby untreated streams the B. glabrata population remained stable and the schistosome prevaleence increased. This method cost U.S. $0.10 per capita prevalence over a year of protection, 5%-10% of the cost of chemical control.