Timothy R. Van Deelen - US grants

Prion diseases are fatal brain wasting diseases of mammals and include Creutzfeldt-Jakob disease in humans, 'mad cow' disease in cattle, scrapie in sheep and goats, and chronic wasting disease (CWD) in North American deer, elk, and moose. Chronic wasting disease is the only prion disease affecting wild animal populations. First recognized in Colorado in the late 1960s, CWD has since been detected in wild and farmed deer and elk across large areas of North America. The infectious agent persists in the environment for years, and this reservoir contributes to the spread of the disease among animals. To date, the relative importance of direct animal-to-animal vs. indirect animal-environment-animal transmission has not been determined for wild animals. This issue has important implications for management of CWD in wild deer and elk populations. A prerequisite for the study of direct vs. indirect transmission of CWD is a method to reliably and efficiently measure the infectious agent in environmental samples. Such a method does not exist at present.

As an initial step toward the goal of determining the importance of direct vs. indirect CWD transmission, this project will develop a sensitive, rapid, and reliable method for measuring infectious prion protein in soil and other environmental samples. The approach taken is to adapt a novel, recently developed biochemical method for environmental samples. This work requires careful examination of how soil properties and environmental factors affect the ability to recover and measure prion protein from soil samples.

Broader Impacts
Potential losses to the economy, hunting, wildlife viewing, and farmed deer and elk from CWD are significant. Increased frequency and geographic distribution of CWD in North America, environmental reservoirs of infectivity, resistance to environmental degradation, and potential for disease transmission between species raise concerns about risks to humans and other species. Development of these new methods will facilitate scientific understanding of environmental contamination, identify routes of disease transmission, improve disease management, and determine long-term risks to humans and ecological systems. The development of a method to measure the disease-associated prion protein in the environment will enable future, critical research on the transmission and spread of CWD.