Eastern equine encephalitis in a free-ranging white-tailed deer (Odocoileus virginianus).

Eastern equine encephalitis (EEE) was diagnosed in a free-ranging, adult, male white-tailed deer (Odocoileus virginianus) from Houston County, Georgia, USA, in July 2001. The yearling buck had neurologic disease and died during transport to our diagnostic facility. Eastern equine encephalitis virus (EEEV) was isolated in Vero cell culture and identified by reverse-transcriptase polymerase chain reaction; as well, EEEV antigen was detected in brain by immunohistochemistry. This is the first report of fatal EEEV infection in a white-tailed deer. Antibodies to EEEV were demonstrated by microtiter neutralization in 14 of 99 (14%) of the white-tailed deer from Georgia sampled in fall 2001. Most antibody-positive deer originated from the Coastal Plain physiographic region. Eastern equine encephalitis virus should be considered a possible cause of neurologic disease in white-tailed deer where it may occur.