The man was the only human case reported in Kane County this year, according to Kane County Health Department officials.
A mosquito can be infected after biting an infected bird, officials say, and then can pass the disease onto humans through bites.
Most people with West Nile virus have no symptoms, but about 20 percent become ill three to 14 days after a bite from an infected mosquito, officials said.
Symptoms are usually mild and flu-like, but serious illness and death are possible, officials said. People older than 50 are at highest risk.
William J. “Bill” Mueller, 76, Lombard’s village president, died Aug. 18 of complications from West Nile virus, combined with a previous diagnosis of blood cancer. He had been hospitalized since Aug. 5.
Health officials recommend mosquito bite prevention as a way to prevent the disease.
Tips on that, and other West Nile information are available at www.kanehealth.com.