2021 West Nile Virus Surveillance Data
Data are updated by 5:00pm every Monday.
Case counts reflect cases completed by local health departments at the time of reporting. Case counts may temporarily decrease if new information needs to be added, but will be included again when information is complete and the case is closed. Case counts may differ from CDC due to the timing of the reports.
Illinois Birds, Mosquitoes, Horses and other Animals
Cumulative totals of West Nile virus infection in birds, mosquitoes and horses by county, municipality and date collected.