St. Louis encephalitis virus transmission to emus (Dromaius novaehollandiae) in Palm Beach County, Florida with evidence of western equine encephalitis virus antibody transport to Florida by emus infected in other states

From November 1993 through January 1995, sera were collected from 59 domestic emus (Dromaius novaehollandiae) at a ranch in Palm Beach County, FL and tested for antibody evidence of arboviral infection. Hemagglutination inhibition (HI) and neutralizing (NT) antibodies to St. Louis encephalitis (SLE) virus were identified in sera collected each year. In addition, HI and NT antibodies to eastern equine encephalitis (EEE) virus and NT antibodies to western equine encephalitis (WEE) virus were detected in emus imported to and then maintained at the ranch. Neither of the equine encephalitis viruses are common in Palm Beach County and many of the EEE and WEE antibody-positive emus were imported from other states prior to vaccination. Emus imported from California, Louisiana and Texas had evidence of naturally acquired antibodies to EEE and WEE viruses. This observation underscores the potential threat of arboviral introduction by infected vertebrates and emphasizes the importance of instituting quarantine procedures to regulate the transport of hosts that may be infected with arboviral agents.