First Human Case of West Nile Virus in Illinois for 2020
SPRINGFIELD – 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.
o 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.
Human West Nile Virus/ Page 2
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