DuPage County Report
The DuPage County Health Department (DCHD) is reporting the first human case of West Nile virus (WNV) in DuPage County in 2025. The individual is a Glen Ellyn resident in their 50s. The onset of WNV symptoms was in mid-July.
WNV is most commonly spread to people through the bite of an infected mosquito. Fortunately, most people infected with WNV do not feel sick. However, approximately one in five people who are infected with WNV will develop symptoms such as fever, headache, body aches, joint pains, vomiting, diarrhea, or rash. Less than one percent will develop a serious neurologic illness such as encephalitis or meningitis (inflammation of the brain or surrounding tissues).
With a rise in recent weeks in mosquito batches testing positive for the presence of WNV, DCHD is encouraging residents to stay safe outdoors by protecting themselves from mosquito bites and the risk of contracting WNV.
There are no vaccines to prevent or medicines to treat WNV infection in people, so the best way to prevent illness from WNV is to avoid mosquito bites and follow the 3Rs of defense:
- Reduce the number of mosquitos and remove containers outside that hold water.
- Repel mosquitos by using insect repellent.
- Report areas where water sits for more than a week.
Residents are encouraged to check the Personal Protection Index (PPI) on the Health Department’s website for the most up-to-date information on WNV activity. The current PPI level has been raised to 2, which indicates high numbers of infected mosquitos in most areas and at least one human WNV case.
The PPI widget is updated by 3PM every Wednesday throughout WNV season. These weekly updates are determined by the Health Department’s vector-borne disease surveillance experts.
WNV activity generally decreases in the fall when cooler temperatures arrive, especially after the first frost of the season. Find additional information at www.cdc.gov/westnile and dph.illinois.gov.
