Illinois has confirmed its first human case of West Nile virus this year, health officials say. The person, who lives in southern Illinois, was hospitalized with complications from the mosquito-borne virus.

(WIFR) - The Center for Disease Control and Prevention confirms Illinois’ first human case of West Nile virus of 2025. A person from Southern Illinois was hospitalized for the infection. Roughly 1 in 150 people who contract the disease develop a severe illness that can affect the brain, spinal cord and nerves.

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