A first-of-its-kind report on ticks and tick-borne diseases in Maine found that about 40 percent of almost 2,000 deer ticks submitted by volunteers and tested last year were infected with Lyme disease.
Incidences of Lyme disease increased in Maine in 2019 to a record 2,079 reported cases, eclipsing the previous high of 1,852 in 2017.
Researchers with the University of Maine Cooperative Extension Tick Lab, which conducted the survey, said spring and summer featured near-ideal conditions for ticks – they survive well in moist, damp conditions and go into a hibernation-like state or perish in extremely dry conditions. Lyme disease is a bacterial infection transmitted by the bite of a deer tick.
Griffin Dill, who manages the tick lab, said the lab’s first tick surveillance report will provide a baseline for researchers conducting what will be an annual survey. Dill said a lot of the people who provided samples found the ticks in their backyards. Each paid a $15 fee to have the tick they submitted tested for Lyme and other diseases.
“People are thinking about ticks when they go hiking or camping, but maybe they’re not thinking about them as much when they’re gardening, doing yard work, or picking vegetables for dinner,” Dill said.
The report includes samples submitted by residents from each of the state’s 16 counties, and from 358 municipalities. A total of 2,697 tick samples – more than 2,000 of them deer ticks – were received. The ticks were collected between April 1 and Dec. 30, 2019.
The report contains detailed data about parts of the body where ticks were found feeding, the types of human activity that attracted ticks, the counties where the ticks were collected, the species of tick, and the type of pathogen found in the samples.
Nearly 40 percent of the deer tick samples tested carried the Lyme disease bacteria, 8 percent carried anaplasmosis and 6 percent carried babesiosis – the three most common tick-borne diseases. Cases of anaplasmosis and babesiosis have also been on the rise in Maine.
Anaplasmosis diagnoses in Maine reached a record high in 2019 with at least 685 confirmed cases. Tick lab researchers said anaplasmosis cases have climbed more than tenfold since 2012.
Symptoms of Lyme and anaplasmosis are similar – fever, joint pain, swelling, fatigue, headaches and neurological problems. But about 25 percent of anaplasmosis patients require hospitalization compared with 5 percent of Lyme disease patients.
Tick Lab researchers found that 529 of the submitted ticks were found by people who were gardening or doing yard work, 267 while walking, and 129 while hiking. Playing outside accounted for 96 tick samples, 29 were found while playing sports, 29 while trapping, 18 while logging, 15 while camping, 10 while bicycling, and five while fishing.
Of the ticks submitted for testing, 95 percent were attached and feeding when they were found.
Most participants found ticks on their legs – about 23 percent – while 17 percent found ticks on their front or rear torsos. Heads and arms accounted for 12 percent and 8 percent were found in the groin area. Six percent of ticks were found on a person’s neck.
The study found that deer ticks were the most commonly encountered species, followed by the American dog tick and the woodchuck tick.
Adult deer ticks are most active from early spring to late fall with peaks in April or May and in late October or early November, the report said. Nymph numbers usually peak in June and early July. Deer ticks can remain active as long as the temperature is above freezing.
Though the report provides a county-by-county breakdown of ticks submitted for testing, its authors emphasize that the data is limited because the samples were submitted voluntarily. Cumberland County residents submitted 347 tick samples, Hancock County 332, Penobscot County 251, and Lincoln County 218. Aroostook County residents only submitted five tick samples.
“Each tick is counted individually, but multiple ticks may be submitted from a single host or person, which can impact the interpretation of geographic data,” the report warns.
On its website, the Tick Lab says its online submission program will be taken down for maintenance, but should be restored by March. Ticks can still be submitted for testing during the shutdown, but anyone interested in doing so should contact the lab at tickID@maine.edu or by calling 207-581-3880.
It costs $15 to have a tick tested for disease. The Tick Lab does not offer medical advice and recommends that anyone bitten by a tick contact their doctor.
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