Illinois records first human case of West Nile Virus this year

ILLINOIS (WCIA) — In Illinois, one community just confirmed their first human case of West Nile virus (WNV) in 2025, while another community said they positively identified their first batch of mosquitos with WNV this year.

The Center for Disease Control and Prevention confirmed that a person from Southern Illinois was hospitalized for WNV. According to public health officials, this is the earliest onset of the disease observed in the state since 2016.

“The fact that we are seeing the first human case of West Nile virus so early in the season serves as a timely reminder – especially for seniors and those with weakened immune systems – to protect yourself from illnesses caused by mosquito bites,” IDPH Director Dr. Sameer Vohra said in a news release. “I encourage all Illinoisans to ‘Fight the Bite’ and take precautions to protect themselves and their loved ones.”

WNV has been confirmed in 19 counties so far in 2025 — including Macon County as of this week. The Macon Mosquito Abatement District (MMAD) tested 180 batches of mosquitos and received two positive results on June 23.

While the risk of infection is currently low, according to the Macon County Health Department, residents are encouraged to check their property and drain/dump any standing water to reduce the mosquito population.

Public health officials offered additional tips to help reduce your risk of infection. This includes following the three “R’s” – reduce, repel, and report:

• Reduce – make sure doors and windows have tight-fitting screens, try to keep doors and windows shut, reduce all sources of standing water where mosquitoes can breed
• Repel – wear shoes and socks, long pants and a light-colored, long-sleeved shirt when outside, and use an EPA-registered insect repellent
• Report – Notify your health department if you see water sitting stagnant for more than a week in your community

You can find out more information about Illinois’ WNV surveillance here.