West Nile Monitoring Report

2022 Weekly Mosquito Monitoring Report

Week of Sept. 26

This week Forest Preserve District staff did not collect any positive West Nile virus samples from DuPage forest preserves. For the year, this brings the total number of positive samples in the preserves to 16. The District began testing forest preserves for the virus on June 1.

The District treats breeding sites near positive samples with a biologically derived larvicide to reduce the Culex mosquito population and then continues to survey the areas for the presence of Culex mosquitoes. 

As of Sept. 30 there have been 129 positive mosquito samples in the county (including those found in DuPage forest preserves) and three human cases, as reflected on the DuPage County Health Department's West Nile virus case map.

To date for the year the Illinois Department of Public Health has reported 20 human cases, three of which resulted in death; 13 positive birds; and 2,325 positive mosquito batches. Up-to-date state information is on the IDPH mosquito surveillance data page.


Fight the Bite

Below are some simple, common sense precautions people can take to avoid mosquito bites and protect themselves against West Nile virus:

1. Avoid being outdoors when mosquitoes are most active, especially between dusk and dawn.

2. When outdoors, wear shoes and socks, long pants and a long-sleeved shirt, and apply insect repellent that includes DEET, picaridin, oil of lemon eucalyptus or IR 3535 according to label instructions. Consult a physician before using repellents on infants.

3. Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut, especially at night.

4. Eliminate all sources of standing water that can support mosquito breeding, including water in bird baths, ponds, flowerpots, wading pools, old tires and any other receptacles. In areas outside of Forest Preserve property, contact your municipal government to report stagnant water in roadside ditches, flooded yards and similar locations that may produce mosquitoes.

5. Public health officials believe that a hot, dry summer could increase mosquito activity and the risk of disease from West Nile virus.

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