Researchers launching tick study after record year for Lyme disease

The University of Maine will launch a pilot program this month to better understand tick populations on the heels of a record-setting year for Lyme disease.

Tick activity is increasing and about to peak in the coming weeks. Meanwhile, researchers plan to study how local weather conditions and the presence of different wildlife species influence tick populations and health risks to humans.

Maine logged a record 2,943 Lyme disease cases in 2023, breaking the record of 2,617 cases set the year before, according to Maine Center for Disease Control and Prevention statistics.

It’s difficult to project how severe 2024 will be for Lyme disease and other tick-borne illnesses, scientists say, because the deer ticks that carry them have only recently become more active after a dormant winter.

The Maine CDC is reporting 261 cases of Lyme disease so far this year, but the bulk of the cases are typically reported in late spring, summer and fall.

“Ticks are here in Maine, they’re active any time the weather is above freezing, and they’re looking for a meal,” said Lindsay Hammes, Maine CDC spokesperson.

Griffin Dill, integrated pest management professional for the University of Maine Cooperative Extension’s tick lab, expects to see more of the arachnids soon, with many different types of ticks actively seeking a blood meal from mid-May through June.

“It’s been a relatively average start to the season, but we are coming up to the real heart of tick season,” Dill said. “We will see adult deer ticks, a peak of dog ticks, and nymphal deer ticks, all overlapping in mid-May to June.”

Dog ticks are not known to transmit disease to humans, but deer ticks that are smaller and harder to spot can transmit Lyme disease, anaplasmosis and babesiosis. Ticks typically need to be attached to their hosts for 36-48 hours before being able to transmit diseases, according to the U.S. CDC.

Symptoms of Lyme disease include a bull’s-eye rash, fever, headache, joint pain and fatigue, although the rash is not always present. If caught early, Lyme disease can be treated with antibiotics.

Anaplasmosis and babesiosis are less common but cause similar symptoms to Lyme, although neither typically causes a rash. There were 777 reported cases of anaplasmosis in Maine in 2023, and 194 cases of babesiosis.

Dill said to learn more about tick activity, the tick lab will be setting up monitoring sites in about 15 places across the state, including Wells, Orono and Bar Harbor. Scientists will gauge tick density and monitor soil temperature, soil moisture and air humidity. They also will set up cameras to monitor wildlife so they can see what hosts are available for the ticks to feed on, aside from humans.

The stations also will monitor for other disease-carrying tick species that have yet to gain a foothold in Maine but have migrated to other parts of the United States, including the Lone Star tick and the Asian longhorned tick.

WHAT MAKES TICKS THRIVE?

Researchers hope to learn what are the best conditions for ticks to thrive, Dill said. Scientists generally believe that ticks do best in warm, humid temperatures, and do worse in arid sunny conditions, or during times of prolonged bitter cold when there’s little or no snow on the ground.

The deer tick’s range has expanded in Maine in recent years, becoming much more prevalent in Midcoast and Down East Maine, as well as becoming more populous in inland areas.

But how many people will contract Lyme is difficult to predict each year, Dill said, because there are so many variables. For instance, there was a slow start to Lyme cases in 2023, after a rainy June kept many people indoors and away form tick habitat. Nevertheless, 2023 ended up being a record year for Lyme cases.

To minimize tick exposure, the Maine CDC recommends being cautious in or around tick habitat, such as under leaf litter, firewood, in gardens or wooded areas. When going into areas where ticks are prevalent, wear light-colored clothing that covers the arms and legs and tuck pants into socks. Use an Environmental Protection Agency-approved tick repellent, perform tick checks. If you’ve been in tick habitat, dry clothes on high heat for 10-15 minutes before washing clothes.