Prairie State Wire

Chronic wasting disease (CWD) has been identified in Putnam, Marshall, Adams, and Peoria counties in Illinois, marking a geographic extension of the disease's presence in free-ranging deer populations in the state, as announced by the Illinois Department of Natural Resources (IDNR). Notably, Adams County records the first case outside the leading edge of the endemic region.

CWD is a fatal neurological disease impacting the white-tailed deer population in Illinois. Detected first near Roscoe in 2002, the disease has now been identified in 25 counties across northern Illinois, with its most southern point in Adams County, located in west-central Illinois.

In routine surveillance efforts during early February 2025, CWD was detected through diagnostic testing in Putnam, Marshall, and Adams counties from hunter-harvested deer. Peoria County confirmed a case in a 2-year-old deer showing clinical signs associated with CWD using similar diagnostics. Adams County samples underwent genetic testing for accuracy, ensuring genetic matches between provided tissue samples and source deer.

Counties affected by CWD in Illinois include Adams, Boone, Bureau, Carroll, Cook, DeKalb, DuPage, Ford, Grundy, Jo Daviess, Kane, Kankakee, Kendall, Lake, LaSalle, Lee, Livingston, Marshall, McHenry, Ogle, Peoria, Putnam, Stephenson, Will, and Winnebago.

The management of CWD is crucial to maintain the health of Illinois' deer herd. Efforts focus on reducing prevalence in affected regions to curb disease spread, maintaining low prevalence for nearly an entire generation of deer hunters.

"Illinois is a national leader in managing and slowing the spread of CWD, and over the past two decades IDNR's program has served as a model for other states," according to IDNR Director Natalie Phelps Finnie.

Despite the lack of evidence connecting CWD to human transmission, the World Health Organization and the Centers for Disease Control and Prevention advise against consuming meat from CWD-positive deer. Hunters are recommended to test their deer and avoid consuming brain, spinal cord, eyes, and other tissues prone to harbor the CWD agent.

Those seeking more information about CWD management in Illinois can find updates online. For specifics on recent detections or CWD in general, Chris Jacques, wildlife disease program manager, can be contacted at chris.jacques@illinois.gov.

IDNR wildlife biologists plan to discuss ongoing management strategies and answer questions about CWD in public meetings to be scheduled later this year. Details on these meetings will be announced in due course, and landowners, hunters, and interested parties are encouraged to participate.