Tick season is booming, and with it come fears about a potentially deadly tick-borne meat allergy.
Discovered a little less than 20 years ago, alpha-gal syndrome is caused by lone star tick bites in the United States, although other ticks can trigger the disease in other parts of the world. At least one person is known may have died from the disease, but scientists know relatively little about it, including how best to treat it. Now, researchers have gathered for the first-ever scientific conference dedicated to alpha-gal to try to find answers.
Doctor Scott Commins from the University of North Carolina School of Medicine, who helped discover alpha-gal syndrome, led the organization of the event, which took place July 7-8. The goal, he said, is to develop “a national set of priorities” for research, funding and education as cases continue to rise.
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Alpha-gal syndrome has long been considered a rare disease in the United States, but a quick search online suggests that it is at the forefront of public consciousness: There are numerous alpha-gal support groups on Reddit and Facebook, while some TikToks about the condition have tens of thousands of likes.
The most popular alpha-gal Facebook group, “The AlphaGal Kitchen,” has 82,000 members, up from 4,000 just two weeks ago, according to Sharon Forsythexecutive director of the Alpha-gal Alliance and the Alpha-gal Alliance Action Fund.
A 2023 from the United States Centers for Disease Control and Prevention study found that between 2010 and 2022, the number of suspected alpha-gal cases increased each year. An estimated 450,000 people have the disease, according to the CDC, but that number may be an underestimate. In a study published July 2, about one in four people in Arkansas, Kentucky, Missouri, Tennessee and Virginia tested positive for the antibody associated with alpha-gal syndrome, although not all were symptomatic.
Despite the growing number of cases and increased public awareness since the discovery of alpha-gal, researchers don’t know much about this syndrome.
What we do know is that the lone star tick and other ticks can carry the alpha-gal molecule, which is naturally present in the tissues of many mammals, but not in humans or other primates. A tick bite can inject the molecule directly into the bloodstream, triggering an immune system response. This response produces a certain antibody that causes an allergy when the affected person eats red meat or other meat products, such as dairy or gelatin.
At the two-day alpha-gal conference, co-hosted by the University of North Carolina at Chapel Hill, the North Carolina Department of Health and Human Services and the CDC, speakers and panels discussed everything from tick populations to the syndrome’s impact on heart valves to gastrointestinal issues.
“Nothing else could put a veterinarian, a doctor, an entomologist and an epidemiologist with knowledge of the same syndrome in the same room,” Commins says.
The risk of alpha-gal is partly an ecological problem. The primary diet of lone star ticks is the blood of white-tailed deer, whose population has skyrocketed thanks to conservation efforts and reforestation of the East Coast after the Industrial Revolution.
“We brought the white-tailed deer back from the brink of extinction,” says Holly Gaffeprofessor of biology at Old Dominion University, who presented at the conference. “When we bring back deer, we bring back their parasites, and then we’re surprised when it happens in our own yards.”
“We created this perfect ecology for lone star ticks to explode,” she says.
The range of lone star ticks is also expanding. While they were once relatively sequestered in the southeastern United States, the arachnids began spreading west and north as white-tailed deer also spread and the climate warmed, Gaff says.
As interactions with ticks increase, so does public and clinical awareness of the disease. It’s “absolutely unambiguous” that diagnoses are on the rise, says Forsyth, an advocate for alpha-gal syndrome awareness.
But alpha-gal syndrome is unpredictable, which can make it difficult to identify.
In some people, the immune response to alpha-gal resembles an allergic reaction to red meat, but symptoms do not appear immediately. It may take hours for signs such as hives, nausea, or difficulty breathing to appear. After eating mammal products, some people with the syndrome experience gastrointestinal problems that may be confused with food poisoning or irritable bowel syndrome. Others can still eat red meat without problem, but if they take, for example, medications containing the alpha-gal molecule, or receive a new heart valve made from a pig or cow, they will have a reaction.
Because the syndrome presents so differently among those affected, Forsyth says, she often acts as a helpline for people with questions about the syndrome.
“Right in the middle of the conference, I received a call from someone who was going to have a medical procedure tomorrow,” she says. “I’m not a doctor and I don’t have any medical training. But they don’t have anyone to talk to and they just found out that their doctor is going to use heparin, which is derived from pig lungs or intestines. So I have to tell them, ‘Here are some documents you can take to your doctor, and then you have to trust them to do a risk-benefit analysis.’
Forsyth also advocates for a policy that would officially recognize alpha-gal as a major allergen and require changes to food and drug labeling. Most pharmaceutical companies, she says, don’t specify whether their products contain alpha-gal.
Researchers don’t know why some people experience such a wide range of symptoms, if any, or why exactly the tick’s saliva causes these different reactions. Commins’ team hopes that a better understanding of tick bites and their effects on the body could lead to more human clinical trials for alpha-gal syndrome and perhaps even a vaccine.
For a field that contains so many different research silos, Gaff says, she appreciated the “multidisciplinary nature” of the conference.
“As researchers and patient groups, we have our own worlds, and so coming together is great. »
