To successfully manage wildlife diseases, it is necessary to understand factors that influence spread. One approach is to analyze host movement and social structure, as these behaviors can be associated with the probability of transmission. Some populations of mule deer (Odocoileus hemionus hemionus (Rafinesque, 1817)) in western Canada are infected with chronic wasting disease (CWD), a transmissible and fatal neurodegenerative disease. We used population analysis of spatial genetic structure of mule deer at broad and local scales to understand factors that influence spread. We genotyped 2535 mule deer sampled from Alberta, Saskatchewan, and portions of British Columbia using 16 microsatellite loci. We found weak genetic structure at broad spatial scales (overall FST = 0.008) that was well defined by geographic distance, indicating the risk of CWD spread from the focus of infection will decline gradually with increasing distance, but there are no barriers to the spread over time. At the local scale of approximately 2 km, elevated relatedness among CWD-infected individuals suggests transmission rates within social groups. Sex-biased spatial autocorrelation in genetic relatedness also indicates that female philopatry underlies the social structure, and therefore transmission among relatives is potentially driving local disease persistence.
Canadian Journal of Zoology

Cullingham, C., Nakada, S.M. (S. M.), Merrill, E.H. (E. H.), Bollinger, T.K. (T. K.), Pybus, M.J. (M. J.), & Coltman, D.W. (D. W.). (2011). Multiscale population genetic analysis of mule deer (Odocoileus hemionus hemionus) in western Canada sheds new light on the spread of chronic wasting disease. Canadian Journal of Zoology, 89(2), 134–147. doi:10.1139/Z10-104