Local health officials are advising residents to continue protecting themselves against mosquito
bites into the fall as they announce this year’s first human case of West Nile virus (WNV) in a
resident of Kenosha County.
Other human cases of WNV illness have previously been reported in Wisconsin this year. WNV
activity has also been reported in mosquitoes and animals in other parts of the state in 2026. The
last reported case in Kenosha County was in 2024.
WNV is spread to people, birds, and other animals through the bite of an infected mosquito.
Mosquitoes acquire WNV by feeding on infected birds. The virus is not spread directly from
person to person, animal to animal, or animal to person.
WNV illness is most common in Wisconsin during August and September. However, the risk of
contracting WNV and other mosquito-borne illnesses such as Jamestown Canyon virus, La
Crosse encephalitis virus, or eastern equine encephalitis virus is present whenever mosquitoes
are active, so it is important for people to be vigilant about preventing mosquito bites throughout
the rest of the summer and into early fall.
Most people who are infected with WNV do not get sick, said Kenosha County Health Officer
Richard Ferrari Traner. Those who do become ill usually experience mild symptoms such as
fever, headache, muscle ache, rash, and fatigue. However, some people (less than 1 percent) who
become infected with the virus get seriously ill with symptoms that include high fever, muscle
weakness, stiff neck, disorientation, mental confusion, tremors, confusion, paralysis, and coma.
Older adults and those with compromised immune systems are at greater risk of developing
severe illness that can be fatal. It is important that people contact a health care provider if they
suspect they have WNV illness, Ferrari Traner said.
The best way to avoid illnesses spread by mosquitoes is to reduce exposure to mosquitoes and
eliminate mosquito breeding sites. Mosquitoes will typically no longer be active once there is a
hard frost (temperatures below 28 degrees for at least four consecutive hours), but until then,
people are urged to protect themselves. The Kenosha County Division of Public Health
recommends the following:
Avoid mosquito bites:
• Apply an insect repellent with DEET, picaridin, oil of lemon eucalyptus, or IR3535 to
exposed skin and clothing.
• Prior to heading outdoors, treat clothing with permethrin; do not apply permethrin
directly to skin.
• Consider rescheduling outdoor activities that occur during evening or early morning
hours, when mosquitoes that spread WNV are most active.
• Wear loose-fitting long sleeves and long pants when outdoors to help keep mosquitoes
away from your skin.
Mosquito-proof your home:
• Prevent mosquitoes from breeding around your home by removing stagnant water from
items around your property.
o Empty standing water that has collected in tin cans, plastic containers, flowerpots,
discarded tires, roof gutters, and downspouts.
o Turn over wheelbarrows, kiddie pools, buckets, and small boats such as canoes
and kayaks when not in use.
o Change the water in bird baths and pet dishes at least every three days.
o Clean and chlorinate swimming pools and hot tubs; drain water from pool covers.
• Make sure window and door screens are intact and tightly fitted to prevent mosquitoes
from getting into your home.
• Trim or mow tall grass, weeds, and vines since mosquitoes use these areas to rest during
hot daylight hours.