Illinois Tick Season Extends Due to Climate Change

Illinois’ tick season is becoming longer, starting earlier, and affecting new areas of the state, according to scientists and researchers. Milder winters and earlier springs contribute to ticks’ increased survival, resulting in earlier cases of tick-related illnesses compared to previous years. Once primarily found in heavily forested regions, ticks are now prevalent in city parks, green spaces, and suburban yards as well.

It’s not true that ticks are only something you’re going to encounter on a camping trip. Increasingly, that’s simply not true. Ticks don’t recognize city limits, said Dr. Kelly Cairns, president of the Chicago Veterinary Medical Association.

Impact of Climate Change

Traditionally, tick season spans from April to September. However, due to human-driven climate change, all seasons are warmer, with winter temperatures rising more than others. This shift causes shorter winters, supporting larger tick populations, especially in the Midwest and Northeast.

Patrick Irwin, lead entomologist with the Northwest Mosquito Abatement District, explained that climate change enables ticks to thrive and activate earlier. Ticks go dormant below 40 degrees and die under 14 degrees. However, recent cold snaps were paired with snow, insulating ticks from the cold. With February, March, and April experiencing above-average temperatures, ticks emerged earlier from hibernation.

This spring, the Northwest Mosquito Abatement District noted a near sevenfold increase in deer tick sightings compared to the previous year, leading to more frequent tick drags in suburban areas to collect data.

Tick Bites and Prevention

Jefferson Park school social worker Ann Miller found a tick on her dog, Millie, which led to an unexpected bout of Lyme disease. Initially, antibiotics weren’t deemed necessary, but symptoms appeared later, requiring doxycycline treatment. This experience highlighted that tick bites can happen earlier than expected in the season. Miller now administers tick medication to her pet earlier in the year.

Dr. Cairns stresses the importance of preventative medication and regular tick checks for pets after outdoor activities. If you know your dog has had a tick on it, please call your vet. It’s not something that you want to wait on, she advised.

Understanding Ticks and Lyme Disease

Ticks employ a strategy called questing to latch onto hosts. In shaded, humid environments like leaf piles, they wait in vegetation to grab onto any passing host. These arachnids feed on blood for days, potentially transmitting bacteria like Lyme disease. Due to their small size, often comparable to a poppy seed, ticks can go unnoticed.

The Illinois Department of Public Health reports about 300 confirmed Lyme disease cases annually. Many patients don’t recall a tick bite, and initial symptoms can resemble the flu, leading to underreporting. As a result, tick-borne disease cases are increasing long-term in Illinois.

Dr. Ihab Ahmed, an infectious disease physician at Northwestern Medicine, emphasizes prevention as the best strategy against tick-borne illnesses. Protective clothing, repellent, and diligent tick checks after outdoor activities are essential. Dressing in light clothing, tucking pants into socks, and using tape as a barrier are practical measures to avoid getting bitten.