White-tailed deer (Odocoileus virginianus) play an integral role in the nat
ural history of Ehrlichia chaffeensis, the causative agent of human monocyt
ic ehrlichiosis (HME). Paraffinized tissues from a white-tailed deer submit
ted as a diagnostic case to the Southeastern Cooperative Wildlife Disease S
tudy (Athens, Georgia, USA) in October of 1985 and originally described as
infected with an unidentified rickettsial organism were re-examined by spec
ific nested polymerase chain reaction (PCR) for evidence of infection with
Ehrlichia spp. Ehrlichia chaffeensis was identified from the bone marrow an
d inguinal lymph node of this deer based on amplification of a characterist
ic sequence-confirmed 16S rDNA fragment from these tissues. Parallel PCR te
sts on the same samples were negative for 16S rDNA fragments of the agent o
f human granulocytic ehrlichiosis (HGE) and for an Ehrlichia-like organism
widely distributed in white-tailed deer populations. This report describes
detection of E. chaffeensis in archived tissue from a deer collected before
the index case of human monocytic ehrlichiosis was established.