Snail-borne disease in changing landscapes
Disease dynamics of complex life cycle parasites are especially sensitive to environmental conditions due to the physiological requirements of the multiple host species they infect. Yet, trematode parasites are transmitted globally in localities with extreme seasonal variation in rainfall or temperature. Transmission is only possible because of the impressive dormancy capacities of their intermediate hosts, aquatic snails. This lecture will primarily focus on the impact of seasonality on the transmission of the neglected tropical disease, schistosomiasis, in Tanzanian farming habitats. I will discuss how ephemerality impacts disease risk for humans and the potential to harness this ecology for intervention of this disease. Snails also transmit trematode disease to livestock globally, such as fascioliasis, causing large economic losses and livelihood challenges to farmers. In both Tanzania and the Netherlands, anthropogenic influences like nutrient pollution and heavy metal pollution can exacerbate transmission risk. Understanding and mitigating these complex disease dynamics requires a one health approach, focusing on environment, animal, and human health.
