information provided by the Illinois Department of Public Health
SPRINGFIELD, Ill. (May 27, 2019) – On May 24, the Illinois Department of Public Health (IDPH) confirmed the first mosquitoes to test positive for West Nile virus in Illinois for 2019. DuPage County Health Department staff collected the positive mosquitoes on May 21, 2019, in Wayne, Illinois.
No human cases of West Nile virus have been reported so far this year.
“The recent rains are leaving many pools of water behind, not only in sewer systems under streets and drainage ditches along roads, but in our own backyards,” said Acting IDPH Director Dr. Ngozi Ezike. “As we start to see higher temperatures, we will start to see more West Nile virus activity. While we see West Nile virus in Illinois every year, it is important not to become complacent.”
Monitoring for West Nile virus in Illinois includes laboratory tests for mosquito batches, dead crows, blue jays, robins, and other perching birds, as well as testing sick horses and humans with West Nile virus-like symptoms. People who see a sick or dying crow, blue jay, robin, or other perching bird should contact their local health department, which will determine if the bird will be picked up for testing.
West Nile virus is transmitted through the bite of a Culex pipiens mosquito, commonly called a house mosquito, that has picked up the virus by feeding on an infected bird. Common symptoms include fever, nausea, headache, and muscle aches. Symptoms may last from a few days to a few weeks. However, four out of five people infected with West Nile virus will not show any symptoms. In rare cases, severe illness—including meningitis, encephalitis, or even death—can occur. People older than 60 and individuals with weakened immune systems are at higher risk for severe illness from West Nile virus.
The first mosquitoes to test positive for West Nile virus in 2018 were collected on May 25, 2018, in Cook County. Last year, 74 counties in Illinois reported a West Nile virus positive mosquito batch, bird, and/or human case. IDPH reported 176 human cases (although human cases are underreported), including 17 deaths.
Precautions to Fight the Bite include practicing the three “R’s”—reduce, repel, and report.
- REDUCE—make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings. Try to keep doors and windows shut. Eliminate, or refresh each week, all sources of standing water where mosquitoes can breed, including water in bird baths, ponds, flowerpots, wading pools, old tires, and any other containers.
- REPEL—when outdoors, wear shoes and socks, long pants, and a light-colored, long-sleeved shirt. Apply insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR 3535, according to label instructions. Consult a physician before using repellents on infants.
- REPORT—report locations where you see water sitting stagnant for more than a week, such as roadside ditches, flooded yards, and similar locations that may produce mosquitoes. The local health department or city government may be able to add larvicide to the water, which will kill any mosquito eggs.
Additional information about West Nile virus can be found on the IDPH website.