Examining covariates influencing the spread of Chronic Wasting Disease among white-tailed deer

Abstract

Chronic Wasting Disease (CWD) is a fatal encephalopathy that is found in at least seven species within the family Cervidae. The disease is caused by the aggregation of misfolded PrP protein in the nervous tissues of the host and was first observed during the 1960s in four captive cervid research facilities in Colorado. However, since its discovery, the range of the disease has ballooned to include most of the contiguous United States, three provinces in Canada, the Korean peninsula, and Scandinavia. Although the pathology of CWD is well-understood, many facets of the disease remain enigmatic. In the first chapter, I examined how interspecific (and conspecific) spread could occur on deer farms by conducting a camera-trap analysis of wildlife interactions both inside and surrounding deer farming facilities. Although this study does not directly address transmission of CWD, it does quantify interactions between wildlife and farmed deer and may help explain how the disease can spread between wild and farmed populations. The second chapter addresses what role winter weather plays in the spread of CWD. Many diseases display fluctuating dynamics mediated by seasonal changes and my second chapter is focused on whether CWD cases in southern Wisconsin could be mediated by winter severity. Collectively, this thesis further underscores the puzzling nature of CWD and points to new areas of research which may help managers and wildlife professionals control its spread.