Mass. takes up new tracking for tick-borne alpha-gal syndrome, which causes red meat allergy

Public health officials began new surveillance tracking for alpha-gal syndrome this spring, and the commonwealth's epidemiologist outlined efforts Wednesday for Massachusetts to collaborate with other states to learn more about the condition spread through lone star tick bites.

Fourteen states now have mandatory reporting requirements for alpha-gal syndrome, also dubbed the red meat allergy, State Epidemiologist Catherine Brown said.

"I don't expect that Massachusetts data alone are going to answer all the questions that we still have about alpha-gal," Brown told the Public Health Council. "But now we can work with other jurisdictions to aggregate data and learn as a group, and then use that information to educate our providers and our public, which again was one of the primary reasons to make this reportable in Massachusetts."

Lab results have shown high or moderate positivity rates for alpha-gal syndrome in Massachusetts, particularly in Barnstable, Berkshire, Dukes and Nantucket counties, she said.

Due to the emerging public health threat, Public Health Commissioner Robbie Goldstein flexed his authority and on April 1 tasked medical providers to notify DPH about new alpha-gal syndrome diagnoses, Brown said. A spokesperson said DPH hopes to share early data "at some point this summer."

Instances of the condition must be reported for one year, but Goldstein can then choose to extend reporting for another year before a more formal regulatory change is needed for ongoing surveillance.

People who are exposed to the alpha-gal molecule — which is found in most mammals but not humans — in tick saliva can then develop allergic reactions when eating meat, Brown said. Less common allergic reactions can surface when people eat dairy products, or are exposed to vaccines or "medical components" that can have a "little bit of residual alpha-gal," she said.

Highlighting data from the New England Center of Excellence in Vector-Borne Diseases, Brown showed maps capturing the spread of lone star ticks in Massachusetts from 2020 to 2025.

"What I want you to appreciate is that there are scattered findings of lone star tick really pretty much everywhere in Massachusetts," Brown said. "What we are aware of is that established populations are primarily found down in southeastern Mass., to include the islands. But we fully anticipate that these, you know, the gaps that you can see on this map are going to start to fill in over time. I don't know how quickly that's going to happen, but I expect it will."