1. National Veterinary Institute (SVA), S-751 89, Uppsala, Sweden
2. Veterinary Laboratory Agency, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK
3. AFSSA-Unité ATNC 31, avenue Tony Garnier, 69364 Lyon cedex 07, France
4. National Reference Laboratory for scrapie and CWD, Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851, Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9