Tick crisis comes into focus

It’s difficult not to know someone on the Island who’s afflicted by some tick-borne infection, from Lyme disease to babesiosis to anaplasmosis, and especially hard not to know an Islander affected by the relatively new but now widespread tick-borne condition alpha-gal syndrome.

It can definitely be said this year is undoubtedly the year of the tick. In July, a 1-month-old contracted the rare Powassan virus. Alpha-gal made national news when The New York Times reported a rise of veganism due to the allergies triggered by alpha-gal syndrome. A wave of fear came as Islanders learned that the only public health officials who work on the issue faced federal cuts. And a national alarm sounded on alpha-gal earlier this month after the death of a man in New Jersey became the first well-documented fatality in the U.S. of an alpha-gal-related allergic reaction from food exposure.

And as the country learns about the condition that’s known all too well on the Island, new data from Martha’s Vineyard Hospital and public health officials indicate just how severe the tick crisis is, and reveal how the Island stacks up against the rest of the state in terms of confirmed and probable cases of multiple tick-borne infections.

“This is a public health crisis — tick-borne illnesses on Martha’s Vineyard. We continue to be a hot spot for Lyme disease, babesiosis, anaplasmosis, ehrlichiosis, and alpha-gal syndrome,” Claire Seguin, chief nursing officer and vice president of operations for the Martha’s Vineyard Hospital, said.

The results were published in the Martha’s Vineyard Community Health Needs Assessment, finalized earlier this week, and include updated context for numbers that place the Island at much higher incidence rates of documented cases than the rest of the state for all tick-borne conditions. The hospital, represented by Seguin, as the main healthcare provider on the Island, and Lea Hamner, contract epidemiologist for the Inter-Island Public Health Excellence Collaborative and the Martha’s Vineyard Boards of Health, held a press conference on Tuesday to discuss and add context to the data and assessment. The report, which had a draft version published a few weeks ago, informs a three-year improvement plan on how to address gaps in healthcare; the improvement plan cycle starts in January.

The Island’s population surges to around 100,000 each summer, but this public health surveillance data encompasses only Island residents. The test for a person whose primary place of residence is in New York, even if they get tested at the Island hospital, is sent to public health officials in New York.

In previous health needs assessments, which collect information through data, interviews, and surveys, tick-borne illnesses never surfaced as high of an issue as the one from this year, which Seguin said is a combination of an increase in people that have contracted tick-borne illnesses but also that the issue is “top of mind” for much of the Island. “It’s become more urgent,” Seguin said.

“There are eight infectious diseases and an allergy on Martha’s Vineyard, and that’s nine too many,” Hamner said.

For decades, the Island’s been disproportionately affected by tick-borne illnesses, and even though Massachusetts is a “high burden state” for ticks, especially for Lyme disease, “Martha’s Vineyard stands out as exceptional,” Hamner said. In fact, Dukes County’s rate per 10,000 people of Lyme, based on confirmed and probable cases from 2020 to 2024, is 11 times higher than the state’s rate. There were 784 Lyme cases, spread by deer ticks, reported to public health between 2020 and 2024 in Dukes County.

The calculations were deduced by Hamner, who used data from the Massachusetts Epidemiologic Virtual Network, Massachusetts Department of Public Health, and population estimates from the UMass Donahue Institute.

The data were gathered for comparison — better, worse, or the same compared with other places — and use a standard criteria applied to all health departments across the country. Hamner compared rates per 10,000 people because the Island hosts around 25,000 year-round residents. “The rate is super-important to be able to compare our Island to the state. And so because, of course, our Island is much smaller than the entirety of Massachusetts, if we just looked at total cases, that wouldn’t be fair,” she said.

Hamner also provided the data for five-year and 10-year ranges because the numbers can be small for more uncommon tick-borne infections, and make year-to-year trends hard to interpret. 

Both spread through deer tick bites, incidence rates of babesiosis, a disease caused by a parasite that infects red blood cells, and anaplasmosis, a disease caused by bacteria, also soar on-Island compared with the state. There were 113 cases of babesiosis between 2020 and 2024, which is 11 times higher than the state rate, and there were 60 cases of anaplasmosis in the same range, which is five times higher than the state rate.

“Babesiosis and anaplasmosis are a step down from Lyme disease and how common they are, but they are still all too common,” Hamner said in the press conference.

Powassan virus and borrelia miyamotoi are also tick-borne illnesses spread through deer tick bites, and though much rarer, as there was only one case for each in the five-year range used in Hamner’s data, the Dukes County rates were eight times and two times higher than the state’s, respectively. These are really rare diseases in Massachusetts, and so that such a small population has seen even one case is notable, Hamner said.

Two other severe tick-borne infections tracked by public health officials are tularemia, transmitted by a variety of ticks and other sources, and dog tick–transmitted Rocky Mountain spotted fever, which Hamner said are “Martha’s Vineyard–specific problems,” and though the numbers don’t touch the amount of Lyme, babesiosis, or anaplasmosis cases, Vineyard cases make up a majority of the cases statewide.

The draft health needs assessment said there was a 500 percent increase in Rocky Mountain spotted fever–positive lab tests performed at the hospital between 2019 and 2024, and a 300 percent increase in positive lab tests for tularemia. But Hamner said this showed that more tests were performed for these illnesses, and “is not the same as more cases.” 

“More testing is good news. Even though few tests are positive overall, early detection is crucial, because timely treatment saves lives,” she added. Increased tests also point to more patient and provider awareness of tick-borne infections, especially rarer ones.

All public health data that reach the desks of Hamner and Betsy VanLandingham, who oversees hundreds of cases as the Island’s only infectious disease case investigator, starts with a positive test. So, especially because of what Hamner said were Island-specific diseases (tularemia and Rocky Mountain spotted fever) compared with the rest of the state, there will be more detections because providers know to look for that here.

Still, Hamner said data for both the Island and state are an undercount overall, because symptoms can take weeks to manifest and test positive. Meanwhile for Lyme, a doctor can see a bulls-eye rash and not need to test to treat, and preventively start a course of oral antibiotics, such as doxycycline. And even for alpha-gal syndrome–positive tests, only a portion of those are real cases where people develop allergic symptoms.

As the Island is already flooded by Lyme cases and other diseases, the rapid infestation of lone star ticks has further burdened the community. Ehrlichiosis, for example, which showed up in 25 cases in Dukes County between 2020 and 2024, boasts a rate on the Island 99 times that of the state. “We are seeing more and more ehrlichiosis cases each year,” Hamner said. “It started off with fewer than five, and now we’re seeing double digits.” This makes sense, Hamner added, because there are more lone star ticks on the Island than in the rest of the state.

Erlichiosis, though, still pales in comparison to alpha-gal syndrome, and unlike other tick-borne illnesses, alpha-gal isn’t a state-mandated reportable condition, and can’t be tracked by state public health officials. Instead, Hamner relies on tests from the hospital.

In 2020, the hospital’s emergency department performed nine tests for alpha-gal, which resulted in two positive cases. In 2024, tests increased to 1,254, and there were 523 positive results; that’s about a 42 percent positivity rate. 

The hospital, which now sends tests to the lab at Mass General Brigham, also provided year-to-date tests of alpha-gal for this year, and as of last week, there were 1,632 tests, 724 of which were positive. It’s not quite the end of the year yet, Seguin said, and the numbers represent a 44 percent positivity rate. The data isn’t de-duplicated, which means the same person may have tested positive more than once, but because that’s been the case all along, Seguin said, they “can look at those numbers and react to them.” The process is analogous to that for COVID-19, where a person can test positive multiple times and not be a unique case, but the tests still count as positive.

“They’re not perfect information, because not everyone who tests positive has symptoms. Some people can be sensitized without clinical allergy, and so they therefore do not have alpha-gal syndrome,” Hamner said. “But the upward trend still clearly shows that more Island residents are being affected year over year.”

There is still a lot to learn about the allergy that was only first identified in 2009, and though other states do report alpha-gal, Massachusetts hasn’t made that step yet. Hamner said there are discussions around whether or not an allergy can be tracked through the standard tools used for infectious diseases now. She added that there are questions that would need to be answered: Who is most likely to develop the allergy? How can we help people manage the symptoms? What treatments or cures might be possible?

Now is a time when public health surveillance systems and state departments as well as local departments are in need of funds, and so Hamner said the idea of a new initiative is a challenge for many states. Cuts recently jeopardized Hamner’s work on the Island, but a fundraiser was set up to garner support and money to support her. The initiative brought in more than $14,000 as of Wednesday. 

“​​It’s not enough to just collect information on the problem. It is critical to put that data to action, together,” Hamner said.