First 2023 Human Case of West Nile Virus Reported in DuPage County

The DuPage County Health Department (DCHD) is reporting the first human case of West Nile virus (WNV) in DuPage County in 2023. A Woodridge resident in their 60s became ill in August.

WNV is transmitted to people by infected mosquitos. 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 continued rise in recent weeks in mosquito batches testing positive for the presence of WNV, DCHD is asking residents to stay safe outdoors by protecting themselves from mosquito bites and the risk of contracting WNV.

The best way to prevent WNV is to avoid mosquito bites and follow the four Ds of defense.

• Drain: Drain those items that collect standing water around your home, yard, or business. Scrub and refill pet water dishes and bird baths regularly.
• Defend: Use an insect repellant containing DEET when outdoors and reapply according to directions.
• Dress: Wear long pants, long sleeves, and closed-toe shoes when outside to cover the skin.
• Dusk to Dawn: Wear repellant outdoors during these prime times for mosquito activity.

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 will be increased from 1 to 2, which indicates high numbers of infected mosquitoes in most areas and at least one human WNV case. The recommended actions are Drain, Defend, Dress, and Dusk to Dawn.

The PPI widget will be updated by 3:00 p.m. every Wednesday throughout the WNV season. These weekly updates will be determined by the Health Department’s vector-borne disease surveillance experts.

WNV activity generally decreases in the fall when cooler temperatures arrive and especially after the first frost of the season. Additional information and resources on WNV prevention are available at https://www.cdc.gov/westnile/index.html and https://dph.illinois.gov/topics-services/diseases-and-conditions/west-nile-virus.html.