5/26/2026

N. WISCONSIN - A Marshfield Clinic Research Institute study found 51 percent of tested deer ticks in Wisconsin carried the bacteria that cause Lyme disease. Nearly 12,500 ticks were submitted through a citizen science project over the last two years, with deer ticks accounting for more than a quarter of the 2024 samples. Wisconsin reported a record 6,469 Lyme disease cases in 2024, with researchers finding higher bacteria rates in southwestern Wisconsin and during the fall. Researchers stressed that a tick bite does not mean a person will get Lyme disease, noting that ticks usually must remain attached for 24 to 36 hours to transmit the bacteria.