Health officials confirm first human case of West Nile virus in Illinois this year

The first human case of West Nile virus has been confirmed in Illinois this year, health officials said. 

The CDC said a Cook County resident in his 80s became ill in mid-June and tested positive for the virus. 

"While we continue to battle the COVID-19 pandemic, we must also remember to take steps to protect our health from other illnesses," said IDPH Director Dr. Ngozi Ezike.  "West Nile virus is something we see every year in Illinois and it is important people take steps to prevent mosquito bites and the viruses they carry by wearing insect repellent and getting rid of standing water around their homes."  

In 2020, 26 counties in Illinois reported a West Nile virus positive mosquito batch, bird, horse and/or human case, health officials said.

There were 42 human cases of West Nile virus in 2020, including four deaths.


West Nile virus is transmitted through the bite of a house mosquito, which has picked up the virus by feeding on an infected bird.  

Common symptoms include fever, nausea, headache and muscle aches.  Symptoms may last from a few days to a few weeks, health officials said.

Severe illness including meningitis, or even death, can occur, but is rare. 

People older than 60 and individuals with weakened immune systems are at higher risk for severe illness from West Nile virus, health officials said.