Maine Records Increase in Lyme Disease Cases

State health data shows 3,976 confirmed Lyme cases as tick-borne illnesses remain a persistent public health concern in Maine.

Updated on Oct. 23, 2026 in Forecasts

A close-up macro view of a deer tick on a blade of grass, representing the increased prevalence of tick-borne illnesses in Maine. — Maine health officials report 3,976 confirmed Lyme disease cases through October 2026, as climate change expands the geographic range of tick-borne pathogens. AI Illustration. Upload story photo >

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Do you consistently take precautions against tick bites when spending time outdoors?

Maine has documented 3,976 cases of Lyme disease through October 20, 2026, marking an increase over the 3,763 cases reported by the same time last year. Tick-borne illnesses like anaplasmosis and babesiosis are also impacting the state as deer tick activity is expected to remain high.

Why it matters

Ticks are expanding their geographic range across Maine due to climate change, elevating the risk of disease transmission for residents. These pathogens remain a threat as long as temperatures stay above freezing.

Maine recorded 1,223 cases of anaplasmosis and 425 cases of babesiosis through October 20, 2026. These figures compare to 1,604 anaplasmosis cases and 352 babesiosis cases reported during the entirety of 2025.

The details

Ticks transmit Lyme disease, anaplasmosis, and babesiosis to humans, with activity levels linked to ambient temperatures. The state's surveillance indicates that tick presence is shifting across various regions, including Down East and Western Maine.

Maine recorded 4,257 total Lyme disease cases in 2025.
State health officials reported 3,763 Lyme disease cases by October 20, 2025.
Maine reached 3,976 Lyme disease cases as of October 20, 2026.
High deer tick activity is expected to continue through mid-November 2026.

Seasonal Patterns

The current rise in tick-borne illnesses follows the documented trend of ticks expanding their geographic ranges into northern and western regions of the state. This shift mirrors data showing that warming temperatures allow for longer windows of tick activity compared to historical norms.

Residents should remain vigilant against tick bites through mid-November, as activity remains high when temperatures stay above freezing. Use recommended repellents and perform thorough tick checks after spending time outdoors in wooded or grassy areas.

The takeaway

Ticks remain a late-season hazard in Maine that requires ongoing prevention efforts until sustained freezing temperatures arrive. Maintaining protective measures through the autumn is essential for reducing the risk of contracting tick-borne infections.