1. ARC-Onderstepoort Veterinary Institute, Exotic Diseases Division, Private Bag X5, Onderstepoort 0110, South Africa
2. Mammal Research Institute, Department of Zoology & Entomology, University of Pretoria, Pretoria 0002, South Africa
3. Centre for Tropical Veterinary Medicine, University of Edinburgh, Edinburgh EH25 9RG, UK
4. Laboratoire Central Veterinaire, BP 2295, Bamako, Mali
5. Organization of African Unity/Inter-African Bureau for Animal Resources (OAU-IBR), PO Box 30786, Nairobi, Kenya