First Human Case of West Nile Virus in Illinois for 2020

First posted on September 9, 2020

The Illinois Department of Public Health (IDPH) is reporting the first confirmed human case of West Nile virus in Illinois for 2020. A DuPage County resident in her 40s became ill in mid-August.

“While we continue to battle the COVID-19 pandemic, we must also remember to take steps to protect our health from other illnesses,” said IDPH Director Dr. Ngozi Ezike. “In an effort to decrease our risk of contracting COVID-19 from indoor settings, many of us are spending more time outdoors while still socially distancing. As we enjoy the outdoors, we need to protect ourselves from other viruses carried by mosquitoes by wearing insect repellent and getting rid of
standing water around our homes.”

Last year, 46 counties in Illinois reported a West Nile virus positive mosquito batch, bird, horse, and/or human case. For the 2019 season, IDPH reported 28 human cases (although human cases are underreported), including one death.

West Nile virus is transmitted through the bite of a Culex pipiens mosquito, commonly called a house mosquito, which 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, 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.

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 long-sleeved shirt, and 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 larvae.

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 humans with West Nile virus-like symptoms. People who observe a sick or dying crow, blue jay, robin or other perching bird should contact their local health department, who will determine if the bird will be picked up for testing.

Additional information about West Nile virus can be found on the IDPH website.