Project background
Swimmer’s itch is a skin irritation caused by a reaction to the larval stage of parasitic flatworms. The lifecycle persists through snails and waterfowl, however humans serve as a dead end host if exposed to the parasite while in a lake. MAISRC researchers hypothesize that the ecological disruption caused by aquatic invasive species, in particular zebra mussels and mystery snails, will increase human exposure risk to the swimmer’s itch parasite. Researchers are looking to understand and describe these complex dynamics through a series of experiments and field surveys. Understanding these relationships have important implications for public health and freshwater ecosystem management.
Swimmer’s itch, or cercarial dermatitis, is a skin irritation caused by an allergic reaction to the larval stage of parasitic flatworms in the Schistosomatidae family. This parasite’s lifecycle involves a definitive host, typically waterfowl, and an intermediate snail host, with humans occasionally serving as dead-end hosts when larvae penetrate their skin. While swimmer’s itch does not pose significant public health risks, it can diminish recreational use of lakes. Key elements of the parasite’s lifecycle and the environmental factors driving outbreaks, particularly in Minnesota’s diverse and evolving lake ecosystems, remain poorly understood. Emerging evidence suggests that aquatic invasive species (AIS) such as zebra mussels and mystery snails may exacerbate swimmer’s itch by altering ecological conditions in ways that favor parasite prevalence.
To address this issue, researchers aim to explore the lifecycle of the swimmer’s itch parasite and its potential links to AIS. They hypothesize that AIS may enhance exposure risk by increasing intermediate snail host populations or destabilizing ecological systems that naturally suppress parasite transmission. The study will assess swimmer’s itch prevalence and severity across invaded and uninvaded Minnesota lakes, combining field data with public health reports and community engagement. These findings will inform targeted research and practical strategies to mitigate swimmer’s itch, offering valuable guidance for lake users, managers, and public health stakeholders in managing this ecological and recreational challenge.