Ticks and Mosquitoes and Bats, Oh My!

With warmer weather arriving, IDPH reminds Illinoisans to take precautions against illnesses that can be spread by various animals and biting pests

SPRINGFIELD – The Illinois Department of Public Health (IDPH) is reminding Illinoisans that warmer
weather means an increased potential for exposure to several illnesses that can be carried by animals or biting
pests. While enjoying outdoor activities, people should take appropriate precautions to reduce their risk of
contracting serious illness.

“Spring and summer provide so many opportunities for outdoor fun all across Illinois,” said IDPH Director Dr.
Sameer Vohra. “It is important to remember that some common biting pests and animals may be carrying
disease that can cause serious human illnesses. Illinois residents should take precautions like wearing bug
repellent and vaccinating their pets against rabies, among other measures, to keep themselves and their
communities healthy and safe.”

There are three main categories of concern this time of year: 

Mosquitoes and West Nile Virus

Each year, IDPH and local health departments test mosquito samples for the presence of West Nile virus. The
first positive mosquito batches for 2026 were recently found in Cook County. While no human cases have been
reported so far this year, in 2025 there were 150 total human cases and ten fatalities across Illinois.

West Nile virus is transmitted through the bite of a Culex 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. Most people infected with West Nile
virus will not show any symptoms; however, in rare cases it can lead to severe illness including paralysis,
meningitis or encephalitis (i.e. brain and nerve infections), or even death. People older than 60 and those with
weakened immune systems are at highest risk for severe illness.

IDPH urges the public to Fight the Bite by 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, and apply an EPA-registered insect repellent that contains DEET, picaridin, oil of lemon
        eucalyptus, IR 3535, para-menthane-diol (PMD), or 2-undecanone 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 to remove
        mosquito larvae.
You can learn more on the IDPH website at West Nile Virus (WNV)

TIckborne Illiness

Ticks can spread a number of potentially serious illnesses, including Lyme disease, spotted fever group
rickettsiosis, ehrlichiosis, and others. Last year, the first confirmed case of Powassan virus, a potentially deadly
illness, was diagnosed in an Illinois resident, although it is unclear if the case was contracted within the state.

The best protective measure against tickborne illness is preventing tick bites, no matter what state you are in.
IDPH has created an interactive Tickborne Disease Dashboard that documents the counties in Illinois where
different tick species have been confirmed as well as the diseases they may carry.

Additional tips for how to avoid tickborne illnesses are below: 
        • Learn about tick removal and symptom awareness here -  Common Ticks
        • Walk in the center of trails. Avoid wooded, bushy areas with high grass and leaf litter.
        Our tick-camper-checklist.pdf provides more details on how to protect yourself.
        • Wear light-colored clothing to make ticks easier to find. Tuck long pants into socks and boots.
        • Apply an EPA-registered insect repellent containing 20% DEET, picaridin, IR3535, or Oil of
        Lemon Eucalyptus according to label directions. The EPA has a search tool that can help you
        find the product that best suits your needs - Find the Repellent that is Right for You | US EPA
        • Conduct full-body tick checks on family members (underarms, ears, belly button, behind knees,
        between legs, waist, hair and scalp) every two to three hours. Also check any gear or pets taken
        on outings. Talk to your veterinarian about how to best protect your pet from ticks.
        • To kill ticks after being outdoors, put clothes in the dryer on high for 10 minutes (or one hour for
        damp clothes).
        • Bathe or shower within two hours after coming indoors. Many tickborne diseases can have
        similar signs and symptoms. If you get a tick bite and develop fever, chills, headache, muscle
        aches, joint pain, fatigue, or rash, within a few weeks, see your healthcare provider.
        • It is often helpful to keep the tick for species identification. Place the tick in rubbing alcohol or
        in a sealed bag/container to bring to your healthcare provider or local health department for
        submission to IDPH for species identification. A submission form can be found on the IDPH
        website.
More information is available on the IDPH website at Tickborne Illnesses.

Rabies in Bats

IDPH also tracks cases of rabies in animals. The disease is most commonly found in bats; so far in 2026, two
bats have tested positive for rabies, one in Whiteside County, the other in Sangamon County.

The greatest risk of exposure comes from bats that make their way into people’s homes. The IDPH website has
information on steps you can take to keep bats out of your home at Bats and Bat Exclusion. If a bat is found
inside a home, try and cover it with a container and contact animal control so it can be tested for rabies.

Illinois residents should also make sure that rabies vaccinations are up to date for pets and any valuable
livestock and horses for which a rabies vaccine is available. If a pet is exposed to a high-risk wild animal –
such as a bat, skunk, raccoons, fox or coyote – pet owners should immediately contact a veterinarian for
advice.

People can get rabies after being bitten by an infected animal or when saliva from a rabid animal gets directly
into a person’s eyes, nose, mouth, or a wound. Bats have very small teeth making their bite marks hard to
see. If you find yourself in close proximity to a bat, do not kill or release the bat before calling your local
health department to help determine if you could have been exposed to rabies and need preventive
treatment. If the bat is available for testing and test results are negative, preventive treatment is not needed.
People may also need rabies preventive treatment after bites from untested skunks, raccoons, fox or coyotes.

If you have been bitten by any animal, seek immediate medical attention. Bite wounds can become infected
and if the animal is high risk for rabies, preventive treatment must begin quickly.

Learn more about Rabies on the IDPH website - Rabies