Massachusetts health officials began treating alpha gal syndrome as a reportable condition this spring and there have already been more than a dozen cases reported on Cape Cod. Local officials say it could just be the beginning of what’s to come.
The Massachusetts Department of Public Health began tracking confirmed cases of alpha gal — the allergen to mammal products passed by lone star ticks — as of April 1. As of early June, there have been 16 cases reported on the Cape, with the majority of those on the Upper Cape.
That’s according to Stephanie Barth, communicable disease investigator and health educator for the Visiting Nurse Association of Cape Cod (VNA) Public Health and Wellness Division. She is working to track alpha gal and other tick-borne illnesses on the Cape.
Barth says that some of those cases were confirmed by doctors prior to April 1, but those have just recently been added to the state’s new tracking system.
Still, she said that because lone star ticks are so hardy, they are expected to spread quickly on the Cape, and the presence of alpha gal could be as intense on the Cape as it is on Martha’s Vineyard, where cases have spiked over the last several years. And that could happen sooner than later.
“We do expect it to grow over time [on the Cape],” Barth told CAI. “In the next five to 10 years, it could be as big a problem as [on] Martha’s Vineyard.”
Barth said that the prevailing theory is that lone star ticks arrived on the Cape by way of seabirds, which is how they are believed to have arrived on Martha’s Vineyard.
Either way, cases have spiked on the Vineyard. By the end of 2020, there were just 2 reported positive tests of alpha gal that year on the island. All of 2025, there were over 700 positive tests reported. Officials at Martha’s Vineyard Hospital reported so far this year that allergists had already seen more than 400 patients with alpha gal.
Some restaurants on the Vineyard have begun offering “alpha gal friendly” options, there is a support group that meets regularly on the island for residents with alpha gal, and some residents carry an EpiPen with them in case of a severe allergic reaction.
Alpha-gal syndrome — or AGS — causes an allergy to all mammalian products, like red meat and gelatin. Some even become allergic to dairy. And mammal products can be in many common household products like wine, some of which contain bovine gelatin. Some medication capsules also contain mammalian products.
Symptoms of alpha-gal include hives, intense itching and severe gastrointestinal issues. The most severe symptoms can include anaphylactic shock. And the allergen can take several weeks, if not months, to appear, which it makes it difficult to identify. It’s called the midnight allergy because more meat products are typically consumed at dinner, and the allergen can take 2 to 8 hours to kick in, when many are in bed.
Barth, the local disease tracker, said that one mystery that healthcare professionals are trying to understand is why some people have more extreme reactions compared to others.
“We have had cases where people were very, very sick if they came into contact with any mammal product, like anaphylactic,” she said.
The first documented death of alpha gal in the U.S. was reported in 2025 when a 47-year-old man, who had no past significant health issues, suffered an allergic reaction from food exposure.
The increase in alpha gal tests on the Cape comes as local hospitals are reporting more cases of tick-borne illnesses in general this year, Barth said. She said that the trend has slowed recently, but there was an increase in hospital visits up from last year this spring.
