Mosquito productivity and surveillance for St. Louis encephalitis virus in Chicago during 1993.

The City of Chicago's Department of Health monitors weekly deposition of egg rafts of Culex species, prevalence of St. Louis encephalitis (SLE) virus-specific antibodies in feral birds, and prevalence of the virus in mosquito pools. The total number of Culex egg rafts collected in 1993 (4,623) was 2-fold greater than for the 1992 mosquito season.