After a slow start to the season, ticks are starting to reemerge in Maine and most of New England, attaching to hosts and spreading diseases, experts say.

Maine set a record in 2022 for Lyme disease, which is spread by the deer tick, with 2,617 cases, surpassing the previous high of 2,167 set in 2019, according to the Maine Center for Disease Control and Prevention.

Other diseases transmitted by ticks, such as anaplasmosis and babesiosis, have also surged in recent years.

Griffin Dill, an integrated pest management professional for the University of Maine Cooperative Extension’s tick lab, said that in recent years, warmer weather in March led to early tick activity, extending the time period when ticks can find hosts and reproduce.

“When the ticks get an earlier start to the season, that benefits them, gives them more chances to reproduce and leads to higher tick populations overall,” Dill said.

But this March, temperatures were slightly lower and observed tick activity for the month appeared to decrease, Dill said. The average March temperature in Greater Portland was 34.9 degrees Fahrenheit, according to the National Weather Service – the coldest March since 2019. April so far is slightly warmer, according to the weather service.


Dill said the number submissions to the tick lab – about 450 samples so far in 2023 – is about half what the lab typically sees at this time of year. People send dead ticks to the University of Maine Cooperative Extension for tick identification and for testing of whether the arachnids are carrying disease.

But Dill said extrapolating what will happen over the coming months to tick populations and Lyme disease cases is impossible to predict, because so many factors go into how the season turns out. The deer tick’s range has also expanded further up the coast and more inland, which scientists believe is correlated to global warming.

“I don’t expect we will have a lower season overall, just a slightly slower start to the season,” Dill said. “There are a myriad of factors that could negate this slow start, so it’s hard to say whether one slightly later start to the spring is going to noticeably impact tick populations.”

The deer ticks submitted to the tick lab are more likely to carry disease, Dill said, and the percentage of ticks submitted that test positive is growing. In 2019, 37% of deer tick samples sent to the tick lab carried Lyme disease, which rose to 43% in 2022. Anaplasmosis and babesiosis in deer ticks rose from about 4%-5% in 2019 to 10%-11% in 2022 of submitted samples, Dill said.

Research about ticks is ongoing, and the University of Maine landed $6.2 million in federal funding to research ways to control tick populations, identify emerging tick species and expand public health efforts. Dill said the research tied to the federal money is expected to begin late this summer or early fall.

So far in 2023, Maine has reported 353 cases of Lyme disease, according to the Maine CDC, although the agency’s public-facing website that reports “real-time” updates of tickborne diseases only has numbers through the end of 2022. Lindsay Hammes, a Maine CDC spokeswoman, said the agency is working on updating the website soon. May is Lyme Disease Awareness Month, and the CDC is planning events to publicize best practices to avoid tickborne diseases.

To prevent ticks from attaching to you, avoid leaf litter, wear long pants and stay on paths when walking in the woods. Wear gloves when carrying firewood. Conduct tick checks if you’ve been in tick habitat.

If you do get bitten by a tick, watch for signs of a bull’s-eye rash, fatigue, joint pain, fever and chills. If caught soon after transmission, tickborne diseases can be eradicated with a course of antibiotics. In most cases, it takes 36-48 hours for an attached tick to transmit Lyme disease to humans, according to the U.S. CDC.

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