For those of us on Martha’s Vineyard, it can sometimes feel as though al pha-gal syndrome is uniquely our problem. A new report from the Centers for Disease Control and Prevention, entitled Alpha-Gal IgE Seroprevalence Among Blood Donors — 10 U.S. States, 2022, reminds us that while our community has experienced extraordinary ecological and public health change in regards to lone star ticks and alpha-gal syndrome, we are part of a much larger national story.

The CDC recently published the first nationwide analysis of alpha-gal IgE antibodies using blood donor samples from 10 states. The findings were striking. Nearly one in four blood donors in Arkansas, Kentucky, Missouri, Tennessee and Virginia had detectable alpha-gal IgE antibodies. As expected, the highest rates occurred in areas where lone star ticks have long been established, while lower rates were seen elsewhere. Rural and suburban communities also had higher rates than urban areas, reflecting where people are most likely to encounter ticks. Although Massachusetts was not included, Maine was, where 10.6 per cent of blood donors had detectable alpha-gal IgE antibodies.

The study reinforces what clinicians have increasingly observed: Exposure to alpha-gal following lone star tick bites is becoming common in many parts of the United States.

The most important message from this study, however, is not how many people tested positive, but what a positive test does — and does not — mean. Developing the allergy itself remains a distinctly different and much less common outcome. The study states: “Because only a small minority of persons who are IgE seropositive have AGS, health care providers should only test patients with clinically compatible symptoms.”

Many people develop antibodies after tick bites but never experience allergic reactions after eating mammalian meat or other mammalian products. A positive laboratory result without compatible symptoms is called sensitization, not alpha-gal syndrome. Testing people without symptoms risks overdiagnosis, unnecessary dietary restrictions and considerable anxiety.

That distinction has been central to our local public health messaging for years. Accurate awareness means understanding both when to test — and when not to. Laboratory testing is an important tool, but symptoms must always come first.

This national study also carries another encouraging message. Alpha-gal syndrome is no longer an obscure condition recognized by only a handful of clinicians and patients. Scientific understanding is accelerating. Public health surveillance is expanding. Researchers across the country are working to better understand why some people develop the allergy while others with the same antibodies never become ill.

On July 7 and 8, experts from public health, medicine, entomology, allergy and immunology, and patient advocacy will gather in Raleigh, N.C., for the first national scientific meeting devoted entirely to alpha-gal syndrome. It is one more sign that this emerging condition is receiving the scientific attention it deserves. I have been invited to present Martha’s Vineyard’s experience at this conference. Newly affected communities like ours have much to contribute to the scientific understanding of this emerging allergy. The meeting also reflects the growing recognition that lessons learned on Martha’s Vineyard have relevance far beyond our shores.

We have experienced a remarkably rapid rate of ecological change on this Island. Since lone star ticks were first identified on Chappaquiddick in 2011, these aggressive ticks have spread throughout Martha’s Vineyard on the backs of our overabundant deer population. As a result, more Islanders have been bitten and more have faced the concerns of alpha-gal syndrome. Yet we are not alone against the lone star tick. Communities across the country are confronting the same questions we have faced. How common is this condition? Who is truly affected? How can we prevent it? And how can we better care for those living with it?

While many scientific questions remain, one lesson is already clear: accurate awareness saves lives. Awareness shortens the path from symptoms to diagnosis. In 2017, researchers at the University of North Carolina found that many patients with alpha-gal syndrome spent an average of more than seven years seeking answers, often experiencing repeated allergic reactions and emergency department visits before receiving the correct diagnosis. More recently, a follow-up study found that as awareness among patients and healthcare providers has grown, the time from symptom onset to diagnosis has fallen dramatically, with many patients now receiving a diagnosis within weeks rather than years.

We have seen that same improvement here on Martha’s Vineyard. I have spoken with Islanders who recognized their symptoms after just one or two reactions because they knew about alpha-gal syndrome. They sought care, received a diagnosis, and were able to avoid what could have been a life-threatening allergic reaction. That is the power of awareness.

Awareness also leads to better data. Better data leads to better science. Better science attracts investment. And investment leads to the prevention strategies, diagnostics, treatments, and public health infrastructure that patients have been waiting for.

Lea Hamner is an epidemiologist with the Martha’s Vineyard Tick Program.