1. National and OIE Reference Laboratory for Scrapie and CWD, Canadian Food Inspection Agency, Ottawa Laboratory-Fallowfield, Ottawa, Ontario, Canada
2. Animal Disease Research Unit, Agriculture Research Services, United States Department of Agriculture, Pullman, WA
3. Department of Pathology, Veterinary Laboratory Agency, Weybridge, United Kingdom
4. Canadian Food Inspection Agency, Lethbridge Laboratory, Alberta, Canada
5. INRA, UR892, Virologie Immunologie Molécularies, Jouy-en-Josas, France