The Kane County Health Department has collected a batch of mosquitoes near Aurora that is the first this year to test positive for West Nile virus.
West Nile is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Most people with the virus have no clinical symptoms of illness, but some may become ill three to 14 days after the bite of an infected mosquito.
Only about two people out of 10 who are bitten by an infected mosquito will experience any illness, which is usually mild and includes fever, headache and body aches. But officials say serious illness, such as encephalitis and meningitis are possible. Those 50 or older have the highest risk of severe or even deadly disease.