Lyme disease cases in Maine so far this year are tracking slightly ahead of 2025, when the state set a record for the tickborne disease.
Megan Porter, health educator with the Maine Center for Disease Control and Prevention, said she can’t project whether 2026 cases will break the record, but the deer ticks that cause Lyme disease are currently active.
“Ticks are active anytime the temperature is above freezing,” Porter said. “The ticks are everywhere, so Mainers should take steps to prevent tickborne diseases.”
As of Oct. 20, the Maine CDC reported 3,976 Lyme disease cases so far this year. Through October 2025, the state had reported 3,763 cases of Lyme en route to logging a record of 4,257 cases last year.
Griffin Dill, who manages the University of Maine Cooperative Extension’s Tick Lab, said he expects there will be high levels of deer tick activity through mid-November.
Dill said deer ticks are now in their adult stage, and are currently searching for hosts, to prepare for laying eggs and surviving the winter. Despite the arid conditions — ticks prefer rainy and humid weather — the arachnids are still active, Dill said.
“They’re pretty well adapted to survive these adverse conditions,” Dill said. “It is by no means a booming year for tick activity, but we are not seeing a significant decrease in activity even though we’ve had dry weather.”
The lab receives thousands of tick submissions every year for identification and research.
The Maine CDC also reported that, through Oct. 20, there had been 1,223 anaplasmosis cases and 425 cases of babesiosis. The diseases, like Lyme, are transmitted to humans by deer ticks. Lyme and anaplasmosis are bacterial infections, while babesiosis is an infection caused by microscopic parasites.
In 2025, the state recorded a total of 352 cases of babesiosis and 1,604 cases of anaplasmosis, according to the Maine CDC.
Symptoms of the three diseases are similar, including fever, chills, fatigue, headaches and body aches, according to the U.S. CDC. Lyme can sometimes cause a bulls-eye rash. Lyme and anaplasmosis can be treated with a course of antibiotics, while babesiosis patients receive anti-parasitic medicine.
Porter said deer ticks are expanding their geographic range. They used to be mostly in coastal, southern Maine, but are now seen farther inland and Down East.
“We are seeing the ticks push into Down East, and increasing cases of tickborne disease in Western Maine,” Porter said.
Ticks are expanding their range due to climate change, scientists have said.
Porter said people can prevent tick bites by doing frequent checks after doing outdoor activities in tick habitat, tucking socks into pants and using repellent. After outdoor activities, Porter said, put clothes worn during the activity into the dryer on high, which will kill ticks.
This story was originally published by the Maine Trust for Local News. Joe Lawlor can be reached at jlawlor@pressherald.com.