1. Exotic and Emerging Avian Diseases, Southeast Poultry Research Laboratory, National Poultry Research Center, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia, USA
2. National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, U.S. Department of Agriculture, Ames, Iowa, USA
3. College of Veterinary Medicine, Konkuk University, Seoul, South Korea