[1] Univ Georgia, Coll Vet Med, SE Cooperat Wildlife Dis Study, Athens, GA 30602 USA
[2] Columbia Univ, Ctr Infect & Immun, Mailman Sch Publ Hlth, New York, NY 10032 USA
[3] Univ Texas Med Branch, Dept Pathol, Ctr Biodef & Emerging Infect Dis, Galveston, TX 77555 USA
[4] Univ Chicago, Dept Pathol, Med Ctr, Chicago, IL 60637 USA
[5] Natl Audubon Soc, Mississippi River Field Inst, Vicksburg, MS 39183 USA