Since the 2001 introduction of West Nile Virus (WNV) into Illinois,some 2,200 human cases have been reported, with over half being the more severe WNV neural disease cases. Evidence of mosquito infection in Illinois has occurred in all years since 2001, and has been found to vary with climatic conditions. [Read more]
Empirical climate models were developed for the Champaign-Urbana area to estimate when the risk of WNV is likely to increase based on 20 years of mosquito species population and temperature data. Two temperature-based models have been developed to provide an estimate of the likely date when the northern house mosquito starts to become the dominant Culex mosquito species and thus increase the risk of WNV to humans.
For the nine Illinois climate divisions, graphical displays of the “difference from normal” of the current temperature and precipitation conditions and the 10-day forecasted temperature and 3-day forecasted precipitation conditions are presented, along with the number of reported pools of mosquitos testing positive for WNV as reported to the Illinois Department of Public Health (there may be time delays in the number of pools). Examples of weather conditions associated with high and low WNV-case years also are presented for comparison purposes.
Mosquito infection rate (MIR) is estimated with statistical models based on rainfall and temperature in the nine climate divisions of Illinois. Relationships between weather parameters and MIR from previous years have been computed for each of the regions based on the methodology developed for the Cook – DuPage County model. These relationships are being used to develop the Climate Division models during the summer of 2015.
Links to information on the current season WNV threat and historical data related to WNV occurrences in Illinois, provided by Public Health agencies and other groups.