What to know about ticks in Mass. this year

The region's cool spring may have an impact on the local tick population.

Lindsay Morris/The New York Times

With warmer weather comes more chances to again enjoy the outdoors here in Massachusetts — and a resurgence of one of Mother Nature’s most pesky creations: ticks.

To be clear, the blood-sucking insects live year-round in the commonwealth. But as state epidemiologist Dr. Catherine Brown told Boston.com recently, their activity is temperature-based, meaning when the weather heats up, more ticks are crawling around.

But especially attentive outdoor lovers may have noticed a lesser number of ticks this spring.

Brown said that with a relatively cool season this year, tick activity is not as high as it could typically be.


“It’s just suppressing tick activity,” Brown said.

But the epidemiologist said just how many fewer ticks there are out there remains unclear. Collecting information on Massachusetts tick populations is not as straight-forward and standardized as collecting the same data for the mosquito populations, she said.

Brown monitors tick activity often through patients visiting hospitals or seeking other medical care after a suspected tick bite, which makes the information collection more sporadic.

“It looked like the activity this year was actually kind of on the higher side of normal until we got into March, and then it started to drop and again, I really think that’s because of how cool the weather has been,” Brown said.

What to know about tick-borne diseases

When it comes to tick-borne diseases, Lyme disease is the most common, Brown said.

According to the U.S. Centers for Disease Control and Prevention, an estimated 476,000 Americans are diagnosed with the disease annually. Symptoms typically include headache, fever, and “a characteristic skin rash called erythema migraines,” the CDC said.

“If left untreated, infection can spread to joints, the heart, and the nervous system,” the agency said on its website.

There are, however, other diseases spread by ticks.

Babesiosis, for example, is spread by red blood cell parasites that may infect humans via a tick bite and can damage the victim’s red blood cells, according to Brown.


In the U.S., most cases happen in the Northeast and the Midwest, according to the CDC. In the Northeast specifically, the disease-carrying parasites can be found “in both inland and coastal areas, including off-shore islands, such as Nantucket and Martha’s Vineyard (Massachusetts); Block Island (Rhode Island); and Shelter Island, Fire Island, and eastern Long Island (New York state),” according to the federal agency.

“Many people who are infected with Babesia microti feel fine and do not have any symptoms,” the agency said. “Some people develop flu-like symptoms, such as fever, chills, sweats, headache, body aches, loss of appetite, nausea, or fatigue.”

Babesiosis can be life-threatening for some individuals, particularly elderly persons; those with serious health conditions such as kidney or liver disease; those with a weak immune system; and those without a spleen, the CDC said.

Brown also highlighted Anaplasmosis, a tick-borne disease that causes “fever, headache, chills, and muscle aches,” according to the CDC.

Severe illness, which can also be life-threatening, could occur if treatment is delayed or a person has other medical conditions, the agency said.

“One of the issues is that all three diseases can kind of present pretty similarly,” Brown said. “You know, people have fever, headache, chills, muscle aches — your standard, ‘I don’t feel well,’ type of thing.”


If someone feels unwell and are not experiencing respiratory problems or other symptoms of COVID-19, they should call their doctor.

“Then they can do the right tests and provide the right treatment,” Brown said.

To help prevent tick bites, the CDC recommends treating clothing and outdoor gear with “products containing 0.5 percent permethrin” and using insect repellents registered with the Environmental Protection Agency.

The CDC also advises avoiding areas with tall grass and leaf litter, checking for ticks before heading indoors, and showing soon after going inside.

What about the mosquito-borne EEE?

Massachusetts experienced an outbreak of the mosquito-borne virus Eastern Equine Encephalitis, a potentially fatal infection better known as EEE, in 2019 and 2020.

EEE outbreaks typically last three years, and Brown said it appears the latest one appears to have ended even before 2021.

No EEE-carrying mosquitoes were detected last year, she said.

“Based on historical patterns, we are expecting that there won’t be a lot of EEE activity,” Brown said. “But it doesn’t change the fact that we plan and prepare as if there was going to be an outbreak this year.”

As for any sense of how the large the local mosquito population will be this year, Brown said it is too early to tell.

Crews typically begin looking at larvae populations around this time of year, with trapping and testing beginning in about mid-June, she said.

“We have found that even looking at larvae populations does not provide a really good predictor of it, what the season actually looks like,” Brown said. “If it stays this cool, that’s really going to suppress the mosquito populations. But if we start to see, you know, the heat bump up, and the earlier the heat pumps up, the better that is for mosquito population.”


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