The risk of being bitten by a tick infected with Lyme disease is now as high in Ohio as it is in Connecticut—a state that's been dealing with endemic Lyme disease for over half a century. Perhaps more alarming: the risk persists even in winter weather.
The findings, from a new study by researchers at Ohio State University, map a dramatic geographic expansion of Lyme disease that has profound implications for public health across the Midwest. This isn't about warmer states finally catching up. This is about ticks thriving in places—and seasons—where they weren't supposed to.
Lyme disease, caused by the bacterium Borrelia burgdorferi transmitted through blacklegged tick bites, was historically concentrated in the Northeast and Upper Midwest. Connecticut has long been the epicenter—the disease is named after Lyme, Connecticut, where it was first identified in 1975.
But climate change has been steadily expanding the range of blacklegged ticks (also called deer ticks). Warmer winters mean more ticks survive to the next season. Longer warm periods mean ticks stay active later into fall and emerge earlier in spring. And increasingly, they're active in winter months that used to be too cold for them.
The Ohio State study quantified what physicians in the region have been seeing anecdotally: Lyme disease is no longer just a Northeast problem. The infection rates in Ohio now match those in states with decades of endemic transmission.
The winter finding is particularly concerning. People don't typically think about tick prevention in January or February. But if ticks remain active during mild winter days—and climate change is producing more of those—then year-round vigilance becomes necessary.
Lyme disease, if caught early, is treatable with antibiotics. But early detection requires recognizing the symptoms: the characteristic "bull's-eye" rash (which doesn't always appear), fever, fatigue, and joint pain. Left untreated, the infection can spread to joints, heart, and nervous system, causing long-term complications.
The practical implications are straightforward: if you live in Ohio or similar Midwestern states, you need to start thinking about Lyme disease the way people in do. That means:
