[1] USDA, APHIS, Vet Serv, Robbinsville, NJ 08691 USA
[2] Ctr Epidemiol & Anim Hlth, Ft Collins, CO 80521 USA
[3] USDA, Natl Vet Serv Labs, Ames, IA 50010 USA
[4] Natl Ctr Anim Hlth Programs, Riverdale, MD 20737 USA
[5] Foreign Anim Dis Diagnost Lab, Greenport, NY 11944 USA
[6] USDA ARS, SE Poultry Res Lab, Athens, GA 30602 USA