1. Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
2. Division of Wyeth, Fort Dodge Animal Health, Fort Dodge, Iowa 50501
3. Field Veterinary Program, Wildlife Conservation Society, Bronx, New York 10460
4. State Central Veterinary Laboratory, Ulaanbaatar, Mongolia
5. National Animal Health Centre, Vientiane, Lao People's Democratic Republic
6. Department of Pathology, University of Tennessee, Health Science Center, Memphis, Tennessee 38106