EASTERN EQUINE ENCEPHALITIS TRANSMISSION TO EMUS (DROMAIUS-NOVAEHOLLANDIAE) IN VOLUSIA COUNTY, FLORIDA - 1992 THROUGH 1994

From May 1992 through October 1994, sera were collected from 204 domes tic emus (Dromaius novaehollandiae) at a ranch in Volusia County, FL, and tested for antibody evidence of arboviral infection. Hemagglutinat ion-inhibition (HI) and neutralizing (NT) antibodies to eastern equine encephalitis (EEE) virus were identified in sera collected during eac h year. In addition, HI and NT antibodies to St. Louis encephalitis vi rus were detected in 3 naturally infected emus. Isolations of EEE viru s were made from emu blood and tissues collected in 1992 and 1994, whe n EEE-related mortality in emus was 14% and 1%, respectively. A total of 259 mosquito pools was collected and tested for arboviruses during the 3-year study. The EEE virus was isolated from 4 of 140 mosquito po ols (2 Anopheles crucians and 2 Culex erraticus pools) in 1992 and 3 o f 10 pools (all Culex nigripalpus) in 1994. Emus vaccinated against EE E virus showed evidence of short-term HI antibody acquisition. Evidenc e of EEE antibody transfer from naturally infected hens to their offsp ring is reported.