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 ticks and Mosquitos. While enjoying outdoor activities, people should take appropriate precautions to reduce their risk of contracting serious illness.
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.
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 Illness:
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.
Walk in the center of trails. Avoid wooded, bushy areas with high grass and leaf litter. Our Camper Checklist 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.
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.
