Chronic wasting disease in Canada: Part 1

Area of Science:

• Veterinary Medicine
• Wildlife Ecology
• Prion Disease Research

Background:

• Chronic Wasting Disease (CWD) is a transmissible spongiform encephalopathy affecting cervids.
• The disease was introduced to Canada in the late 1980s/early 1990s through imported farmed elk.
• Limited knowledge about CWD at the time of introduction complicated early management.

Purpose of the Study:

• To provide Canadian readers with an overview of published literature on CWD (1980-2002).
• To explain Canadian regulatory approaches to CWD surveillance and control.
• To highlight differences in CWD epidemiology between Canada and the United States.

Main Methods:

• Literature review of PubMed and Medline databases using keywords: chronic wasting disease, prion, diagnosis, transmissible spongiform encephalopathies, CWD and deer, CWD and elk, CWD and environment.
• Inclusion of Canadian publications, unpublished observations, and government/non-government internet resources.
• Analysis of Canadian Food Inspection Agency (CFIA) documents.

Main Results:

• CWD appears to have been introduced via farmed elk imported from the US.
• Canadian eradication efforts have successfully controlled CWD spread within the farmed elk industry.
• Public health implications and differing CWD features in Canada compared to the US were noted.

Conclusions:

• Canada has developed a surveillance and control program for CWD based on scientific understanding.
• While CWD is controlled in farmed elk, managing the disease in free-ranging cervids presents ongoing challenges.
• Part 2 of the study will detail surveillance activities and discuss CWD eradication feasibility.