In 2017, Maine’s incidence of confirmed Lyme cases was 107 per 100,000 residents, the highest of any state. That number dropped by 24 percent from 2017 to 2018 — from 1,852 cases to 1,405 cases, possibly due to
the drought that affected much of the state that summer. But Sara Robinson, Infectious Disease Epidemiology Program Director for the Maine CDC, isn’t optimistic that trend will continue for 2019.
[Why we don’t have a vaccine for Lyme disease]
“It’s a little tricky to talk about cases for 2019 because we’re still processing them all,” Robinson said. “But our expectation, based on anaplasmosis and babiosis [two other tick-borne diseases] trending up, is that Lyme will as well.”
Lyme disease is typically treated by a regimen of antibiotics. In addition, efforts are underway to create an
effective vaccine for Lyme disease for humans, but there’s currently no indication of when or if a vaccine will make it to the market. Other tick-borne diseases are at an all-time high
Though Lyme is the most common tick-borne disease in Maine, there are four other tick-borne diseases that have been documented in the state. They are
anaplasmosis, babesiosis, Borrelia miyamotoi disease and Powassan encephalitis. All five diseases are transmitted by the deer tick.
After Lyme, anaplasmosis and babesiosis are the most common, and confirmed diagnoses of both hit an all-time high this year.
“We’re seeing an increase and there are potentially a lot of factors contributing to that,” Robinson said. “There are a lot more labs in the state that are testing for those diseases, so it’s easier to get a test result than it used to be. But we also think that more people are getting sick.”
The Maine CDC actively updates numbers on diagnosed cases of both anaplasmosis and babesiosis throughout the year, providing
near real-time data through the Maine Tracking Network. As of Dec. 19, the network displayed 686 cases of anaplasmosis and 138 of babesiosis in Maine this year.
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New tests for tick-borne diseases
At the University of Maine Cooperative Extension Tick Identification Lab, 2019 marks the first year the lab has offered testing for tick-borne diseases in tick samples sent by the public. The cost: $15 per tick.
The lab launched the service on April 1, and since then have tested around 2,000 ticks for Lyme, anaplasmosis and babesiosis. They’re still collecting data for an end of year report, which will be made available to the public sometime early next year. However, the lab had some preliminary data they were open about sharing.
“Of the 2,000 ticks, we found that roughly 45 percent tested positive for one of the three pathogens,” said Griffin Dill, who manages the Tick Lab within the Diagnostic and Research Laboratory. “Around 38 percent tested positive for … Lyme; 8 percent for anaplasmosis and roughly 6 percent for babebiosis.”
The information collected from this testing is intended to provide surveillance information on ticks and tick-borne diseases in Maine. The lab stresses that anyone who has been bitten by a tick should not wait until tick testing results are available to consult a physician. Lyme and other tick-borne diseases are best treated in their early stages.
All three diseases are typically diagnosed in people through blood tests and treated with antibiotics. In fact, the U.S. Food and Drug Administration granted clearance to a new test system, ZEUS ELISA, for detecting Lyme disease in humans in July. The new modified two-tiered test is described as “streamlined” and “easier to interpret”
in an FDA press release about the advancement.’
“It’s supposed to be easier to interpret, but I haven’t seen any results from this yet,” Robinson said. “As far as I know, nobody in Maine uses it yet.”
In the near future, the UMaine Tick Lab plans to add more tick-borne pathogens to its test panel. The additions will include
Borrelia miyamotoi, a bacteria that’s transmitted by deer ticks and causes a disease that has similar symptoms to Lyme disease, and Rocky Mountain spotted fever, which is being diagnosed more frequently in southern New England. Teaching about ticks
The Maine CDC recently worked with the Department of Education to approve
a curriculum about ticks and tick-borne diseases designed for grades 3 through 8. The curriculum was taught to teachers from 10 Maine schools last year, and reached classrooms in 2019.
“We’re offering training to teach the teachers,” Robinson said. “We’re hoping to reach more schools that way.”
In addition, the Maine CDC recently launched
social media accounts and a YouTube channel featuring short videos on tick-related topics including how to conduct a thorough tick check, ways to prevent tick bites and how to properly remove an embedded tick.
“They’re targeted towards individuals over the age of 65 because they do have the highest rates of all three diseases in Maine,” Robinson said.
A look to the near future
As temperature averages continue to climb due to climate change, ticks are continuing to spread throughout the state and become numerous in regions that never saw them before.
The deer tick is currently Maine’s chief concern, but other tick species that live in warmer climates also carry dangerous diseases. Researchers are just waiting for them to cross the border.
“We’re keeping an eye out for other types of ticks,” Robinson said. “We’ve intentionally gone out and looked for Lone Star ticks. We find them occasionally, but we don’t find sustainable populations of them so we don’t think they’re surviving in Maine yet.”
Credit: Griffin Dill | University of Maine Cooperative Extension
The Lone Star tick — named for the star-shaped mark on its back — has spread south throughout much of New England and has been found in small numbers
in southern and coastal Maine communities. It’s capable of transmitting a number of diseases, including STARI (Southern tick-associated rash illness) and ehrlichiosis. They can also cause people to become allergic to red meat.
Another tick that experts are looking out for is the
Asian longhorned tick, which has spread rapidly through many states in recent years. This tick species is capable of transmitting Lyme disease, Japanese spotted fever and thrombocytopenia syndrome virus (SFTSV), which can cause a hemorrhagic fever. Unlike other ticks, it can reproduce without mating. And it’s been found as close as Connecticut.
“As ticks move, there’s a potential it could make its way here, so that’s something we watch out for and monitor,” Robinson said.
To get a better understanding of the types of ticks and diseases currently on the landscape, researchers at the UMaine Tick Lab conduct field surveys and collect samples. This winter, they’ll be testing ticks collected from every county in Maine, Dill said.
“We’d certainly like to increase that field survey work to be more reflective of different geographic locations and habitats in the state,” he said, “so we can get a really good understanding of where these ticks are being found and can track them as they move throughout the state.”
Maine residents can help researchers track ticks and tick-borne diseases by sending ticks to the UMaine Tick Lab for free identification. For more information, visit