Host/ectoparasite interactions

Ectoparasites vary considerably in feeding mode and life history. This variation in turn affects how ectoparasites respond to processes operating on different scales. Using Bayesian hierarchical modeling techniques, I am investigating how an ectoparasite’s life history, specifically the portion of the life cycle spent on-host, affects whether the host individual or the external environment play a bigger role in ectoparasite occupancy.

Environmental effects on disease transmission and prevention

Urbanization can affect the transmission and management of zoonotic diseases via changes in host ecology or management strategies. This is particularly true for the raccoon variant of the rabies virus, for which urbanization results in increased population densities of the raccoon hosts and presents challenges for deployment of the oral rabies vaccine (ORV). With my collaborators Amy Davis, Kathy Nelson, Rich Chipman, and Amy Gilbert at USDA APHIS, I used a Bayesian hierarchical model to jointly estimate raccoon abundance and rabies seroprevalence in the urban landscape of Burlington, Vermont. We found that seroprevalence varies spatially, but the cause of the spatial variation is still unclear.

I will build on this work by using agent-based models to answer two questions: 1) does the seroprevalence threshold for local rabies elimination differ from the threshold needed to prevent invasion? 2) Does landscape structure affect either of these thresholds? I anticipate that the threshold for local elimination will be lower than the threshold for resistance to invasion, and that landscape barriers such as rivers and highways will lower seroprevalence thresholds further by subdividing raccoon populations.