Chronic Wasting Disease: The Effects of Environmental Prion Density and Interactions between Populations on Disease Dynamics
Chronic wasting disease (CWD) is a degenerative and fatal prion disease affecting cervid (deer and elk) populations in North America. While the disease exists in captive herds throughout the western United States and southern Canada, the only free-ranging populations afflicted are in northern Colorado, southeastern Wyoming, and the western panhandle of Nebraska. CWD, similar to other prion diseases such as scrapie in sheep, bovine spongiform encephalopathy in cattle, and Creutzfeldt-Jacob disease in humans, attacks the central nervous system via an accumulation of abnormal prion proteins. For this investigation we use both analytical and computational approaches to model the dynamics of the disease in mule deer populations. We focus on modifying the structure of an existing model, integrating sources of infection previously excluded from other CWD models. We proceed to model the effects of two interacting populations and the subsequent impact on disease dynamics. We hope that our analysis and simulations will help in the development of spatial models to be used in CWD management, a central goal of wildlife management agencies.