The Kane County Health Department reported Friday it has found three more batches of West Nile virus-bearing mosquitoes.
The batches were found in department traps in Montgomery, Aurora and Carpentersville. It's the second batch in Carpentersville. Five have been found in total.
There have been 50 reported cases of the disease in humans over the last 10 years in Kane County, including one case in 2011 and five in 2010. None have been reported this year.
Even during this drought, the mosquitoes can breed in a small amount of water, such as that left by brief showers, according to the health department.
To view a map of the county's trap locations, click here.
West Nile virus 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 might become ill three to 14 days after being bitten.
As part of the West Nile program, the health department is collecting dead birds to be sent to the state lab for testing. Call (630) 444-3040 to report dead birds -- such as crows or blue jays -- that do not show any signs of decay or trauma.
People also can call the state's West Nile virus hotline at (866) 369-9710 weekdays from 8 a.m. to 5 p.m.