Distribution of St. Louis encephalitis viral antibody in sentinel chickens maintained in Sarasota County, Florida: 1978-1988.

Sentinel chicken flocks monitored arboviral transmission at 12 sites in Sarasota County, Fla., from 1978 through 1988. During this time, 3,452 serum samples were analyzed for hemagglutination inhibition antibody to St. Louis encephalitis virus (SLE) and eastern equine encephalomyelitis virus (EEE). Overall, 91 chickens seroconverted to SLE and three to EEE. The intensity of SLE transmission showed considerable year-to-year variation. Chickens from south-county flocks were more likely to seroconvert to SLE virus than chickens maintained at the north-county sites. The SLE seroconversion rate for midcounty sentinels was intermediate between north- and south-county sites. Chickens were caged in four habitat types: oak hammocks, slash pine-saw palmetto areas, pastures, and urban-residential areas. There was no significant difference in SLE seroconversion rates between habitats.