From the McHenry County Department of Health:
Ticks are active: Take steps to prevent illness
McHENRY COUNTY, IL – The McHenry County Department of Health (MCDH) encourages residents to enjoy the outdoors while taking precautions against tickborne illnesses.
Local cases of anaplasmosis, a less well-known but potentially serious illness, are on the rise.
Anaplasmosis is a bacterial infection transmitted by blacklegged (deer) ticks. Symptoms typically appear within one to two weeks of a tick bite and can include fever, chills, severe headache, muscle aches, nausea, and loss of appetite. If untreated, anaplasmosis can lead to serious complications, especially for older adults or those with weakened immune systems. In previous years, McHenry County has mostly seen 0 or 1 case annually, with the highest prior total being 3 cases in 2023. So far this year, five cases have been reported, a notable increase compared with previous years.
Although Lyme disease is more widely known, awareness remains important. Like anaplasmosis, it is transmitted by blacklegged ticks and can cause fever, chills, headache, fatigue, muscle aches, and a characteristic erythema migrans, or bullseye, rash. While 2025 cases are lower than in previous years, Lyme disease continues to be more common than anaplasmosis.
Treatment for both anaplasmosis and Lyme disease is most effective when started early. Antibiotics reduce the risk of long-term complications, so anyone who develops symptoms after a tick bite should contact a healthcare provider promptly.
Prevention is the best defense against tickborne illness. Ticks live in grassy, brushy, and wooded areas, so staying on the center of trails and avoiding tall grass or overgrown brush helps reduce exposure. Light-colored clothing makes ticks easier to spot, and wearing long sleeves and long pants tucked into socks or boots provides added protection. Use Environmental Protection Agency (EPA) – registered insect repellents with DEET or permethrin according to label directions.
After spending time outdoors, it is important to check the body, clothing, and pets for ticks. Showering within two hours may help wash off ticks that have not attached. Prompt removal of ticks reduces the risk of illness, and carrying a tick removal tool can make removal easier.
Resources are available for residents who want help identifying ticks. The MCDH has also put together a resource list for organizations that can help identify ticks and test for Lyme disease, babesiosis, and anaplasmosis. The full resource list is available here. Residents may bring ticks to MCDH’s Division of Environmental Health for free identification. The CDC also provides guidance online. MCDH’s Division of Environmental Health, located at 667 Ware Road, Suite 110 in Woodstock, is open Monday through Friday from 8 a.m. to 4:30 p.m. and can be reached at (815) 334-4585.
For additional prevention information, visit MCDH.info or the CDC website.
