Batches of mosquitoes collected in two suburbs in southern Cook County have tested positive for West Nile virus, health officials said Thursday.
One batch was collected May 21 in Oak Lawn, according to the Illinois Department of Public Health. The other was collected May 26 in Evergreen Park.
They are the first confirmed positive batches of mosquitoes in northern Illinois this year, IDPH said in a statement.
“We have confirmed mosquitoes testing positive for West Nile virus from southern Illinois to northern Illinois,” IDPH Director Nirav Shah said in the statement.
“Although the county in which you live may not be reporting a West Nile virus positive result, you still need to take precautions as we’re seeing positive results from across the state,” Shah said.
West Nile virus is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Common symptoms include fever, nausea, headache and muscle aches, the health department said.
Most people infected will not show any symptoms, but in rare cases patients can be come severely ill or die. Those over 50 and people with compromised immune systems are at higher risk for severe illness.
To avoid West Nile, residents should limit time outside between dusk and dawn, when mosquitoes are most active. Eliminate sources of standing water, and wear long sleeves, pants and mosquito repellent when outside, health officials recommend.