U.S. health officials are warning of a surge in Lyme disease and other tick-borne illnesses as tick activity begins earlier [5].
This trend indicates a growing public health risk as ticks expand into more populated areas, increasing the likelihood of human exposure. Scientists said a warmer climate and changing ecosystems are driving the earlier onset of tick activity and the expansion of tick populations [2, 3].
Dr. Stephanie Haridopolos, Deputy Assistant Secretary for the U.S. Department of Health and Human Services, and various state health officials said the threat is increasing [1]. The surge is particularly evident in the Midwest, with significant spikes reported in Michigan, Ohio, and Wisconsin [3, 4, 2].
In Michigan, Lyme disease cases have nearly quadrupled since 2022 [1]. This surge manifested in the spring of 2026, when emergency-room visits for tick bites reached a decade-high for three consecutive weeks [4].
Ohio has seen a similar long-term increase. The state reported over 1,800 Lyme disease cases by 2024, a sharp rise from fewer than 40 cases in 2010 [3]. Local data further illustrates the trend; the Barry-Eaton Health Department recorded 101 Lyme disease cases in 2025, compared to 54 cases in 2024 [2].
Health officials said the combination of expanding habitats and shifting seasonal patterns creates a wider window for potential infections. The spread into new regions means populations that previously faced low risk are now more vulnerable to tick-borne pathogens.
“Lyme disease cases in Michigan have nearly quadrupled since 2022”
The shift in tick behavior and geographical distribution suggests that Lyme disease is no longer confined to traditional hotspots. As warming temperatures allow ticks to survive in northern latitudes and emerge from dormancy earlier in the year, the window for preventative measures must expand. This puts increased pressure on healthcare systems to diagnose tick-borne illnesses in regions where clinicians may be less accustomed to seeing them.
