Gammaherpesvirus Detection in Apparently Healthy White-tailed Deer (Odocoileus virginianus) from Illinois, USA

Numerous gammaherpesviruses can infect cervids, including those that cause malignant catarrhal fever, a lymphoproliferative disease of artiodactyls. Less is known about unclassified gammaherpesviruses in cervids, although they appear to be nonpathogenic in their adapted hosts. Adenoviruses can also cause disease in cervids, characterized outbreaks of localized or systemic vasculitis, especially in juveniles. We tested 31 samples from 24 white-tailed deer (Odocoileus virginianus) captured in Cook County, Illinois, USA for herpesviruses and adenoviruses via consensus PCR of combined nasal-rectal swabs. Over one-third (35%, 11/31) of samples, constituting 42% (10/24) of individual deer, were PCR-positive for a herpesvirus most similar to an unclassified gammaherpesvirus previously found in mule deer (Odocoileus hemionus) in Washington, USA and Saskatchewan, Canada. No deer tested positive for adenoviruses. All deer were apparently healthy on physical examination. Gammaherpesvirus detection is common in white-tailed deer in Cook County and does not appear to be associated with clinically apparent disease. However, the impact of this virus on white-tailed deer fitness or on non-adapted hosts is unknown.