Mosquito Larvae

SPRINGFIELD, Ill. (WAND) - The Illinois Department of Public Health (IDPH) confirmed the first human case of West Nile Virus (WNV) in the state on Wednesday. 

IDPH said the confirmed case involved someone from Piatt County. 

The organization added that three other people are being tested for WNV in northern Illinois. 

The virus has been found in 50 counties this year, after being identified in 73 counties in 2025. According to IDPH, there were 150 human cases last year, including 10 deaths. 

Mosquito batches have tested positive for the virus in Macon, Champaign and Christian counties. Christian County reported that its county health department identified a second WNV-positive mosquito sample earlier this month.

The full list of counties where WNV has been located in mosquito batches is available online. 

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