Ehrlichia chaffeensis in archived tissues of a white-tailed deer

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.