First 2017 West Nile Case Detected In Illinois

(CBS) -- For the first time this year, a human case of West Nile virus has been confirmed in Illinois.

The Illinois Department of Public Health announced Thursday that a Will County man in his 60s became ill with the virus at the end of June.

"Symptoms they're typically going to be mild," Department Spokesperson Melaney Arnold said. "They include fever, nausea, headache and muscle aches. It's kind of like having a cold or the flu."

But some human cases can be more severe. Illinois saw 155 in 2016, including six deaths. Arnold said flooding in parts of the state and warmer weather mean Illinoisans must step up their prevention.

"Make sure that they wear insect repellant when they're outside, especially at night between dusk and dawn when the mosquitoes are most active, and then get rid of any standing water around your house. That's where mosquitoes like to breed."