Transmission potential of human schistosomes can be driven by resource competition among snail intermediate hosts

Abstract

Significance Predicting how ecological interactions among vectors or intermediate hosts of human parasites influence transmission potential to humans remains challenging. Here, we focus on human schistosomiasis and demonstrate how resource competition among snails profoundly alters the link between infected snails, the target of control, and schistosome cercariae, the cause of human infections. We integrated an individual-based bioenergetics model of snail and schistosome dynamics with experiments in artificial waterbodies and field observations to anticipate and explain how resource-sensitive schistosome infections and resource competition among snails interact to generate brief peaks in transmission potential when snail populations grow from low densities. A resource-explicit view of snail and schistosome dynamics could maximize the potential for snail control methods to contribute to control of schistosomiasis.