HATTIESBURG — Mississippians are no strangers to ticks, but residents of the Magnolia State may be surprised to learn that these pesky parasites are capable of spreading a food allergy that makes red meat particularly hazardous. 

The allergy, known as alpha-gal syndrome, affects hundreds of thousands of Americans and is particularly prevalent in the southeastern United States, where ticks thrive due to the warm, humid climate. 

Southern Miss tackles the issue 

University of Southern Mississippi researchers are among the many clinicians and scientists working to understand the allergy, which can prompt anaphylactic reactions to foods like beef, pork or lamb. It can also cause reactions to products made from mammals, including gelatin and some pharmaceuticals, including snake antivenoms. 

Dr. Shahid Karim, a Southern Miss biology professor, studies ticks and the numerous diseases the tiny arachnids can spread to their hosts. 

He began studying alpha-gal syndrome in 2015 after hearing about it from a colleague while in one of the university’s recreational facilities. 

“I was talking to Dr. (Rick) Green … we were in the locker room,” Karim said. 

A ‘thunderbolt’ 

Green, a now-retired recreational therapy professor, shared that he suffered from the allergy, which usually begins with the bite of the lone star tick. This type of tick, named because of its star-shaped spots, is indigenous to the eastern U.S. as well as Mexico. 

“(The allergy) came on like a thunderbolt,” Green said. “I never really had any allergies. And I remember, about 10 years ago … my last day of teaching session one in summer … so, I go running home and I grab two cheeseburgers from McDonald’s. And, next thing I noticed, my palms were itching … and then my whole head started itching.” 

After a trip to an urgent care clinic and three doses of the antihistamine Benadryl, Green said he felt better, but the allergy — which was, at the time, mysterious to both Green and his doctors — would soon resurface. 

“I still had no idea (about the cause of the allergy),” he said. “I was up in Canada visiting friends, and I ate lamb. (The) same thing happened.” 

Green, a member of a Birmingham-based orienteering club, told fellow club members about his allergic reactions. Shortly thereafter, a club member called him with some intriguing information. 

“A woman from the club called me up, and she said, ‘I read something about allergies, and it could be you’re allergic to red meat … and it could very well be caused by a tick bite,’” Green said. “I made an appointment with the doctor, and I told him, ‘I think I’m allergic to beef as a result of a tick bite.’ He goes, ‘I’ve never heard of that.’ None of the (local) doctors had ever heard of it. The only person I knew who had ever heard of it was (Karim).” 

Green said he was happy to have answers and was able to adapt his diet to avoid trigger foods. 

“For (several) years, I was a pretty strict vegetarian, and so I knew how to cook good vegetarian meals,” he said. “I really didn’t miss the meat that much. And then it all went away. (I had it) for about 10 years.” 

The retired professor said the intensity of his alpha-gal syndrome symptoms faded with time. He is now able to eat cheeseburgers — one of his favorite foods — and that he is “not afraid to eat meat.” 

Green said he was delighted to know Karim and share his experiences with his biology colleague. 

“I think he was as much interested in me as I was in him … because he had a live subject that didn’t mind answering questions about (alpha-gal syndrome),” he said. 

A growing problem 

After his initial conversation with Green, Karim returned to his lab with a new research interest, and he successfully applied for university funds as well as federal grants to study the allergy. 

He discovered that, in 2012, there were only 12 documented cases of alpha-gal syndrome throughout the country. 

“So, 2012, 12 cases, and then the (U.S. Centers for Disease Control and Prevention) put together a study,” Karim said. “They found 34,000 cases in 2016, and, in 2023, 450,000 cases, and (those numbers) are increasing every day.” 

The reasons behind the vast increase in alpha-gal syndrome cases are under scientific review, but one possible explanation can be found in the movement of ticks spreading the allergy, he said. 

“Historically, the lone star tick was kind of in a territory — the southeastern United States — and now, you can find it in Canada, in New York, in colder places,” Karim said. “It has increased its geographic range, so there are a lot of cases coming from, like, New York City.” 

The biology professor said factors behind the range change included “longer summers” and overall climate changes. 

“(The ticks) are moving to new territories, and they are surviving,” he said. 

The immune system responds 

Alpha-gal is a complex sugar found in the tissues of non-primate mammals, including cows, pigs and sheep. It is not naturally present in humans, which is why the immune system can recognize it as foreign and react to it, Karim said. 

“(Alpha-gal) was once in our bodies, but, like, 20, 30 million years ago, we deactivated (it),” he said. 

Lone star tick saliva contains alpha-gal, and tick bites transmit it to humans, he added. 

“Red meat already has a lot of alpha-gal in it so, when (alpha-gal syndrome sufferers) eat it, they digest it after 3-6 hours, and that alpha-gal goes and triggers this cascade of reactions,” Karim said. 

The time delay is likely due to it taking longer for the alpha-gal molecules to digest, according to a report from the Mayo Clinic.

The report adds that symptoms of alpha-gal syndrome may include:

• Hives and itching.
• Swelling.
• Wheezing or shortness of breath.
• Stomach pain.
• Diarrhea.
• Vomiting.
• Life-threatening anaphylaxis, in severe cases. 

Clinic staff advise people with such symptoms to see their primary care doctor or an allergist. They also recommend getting emergency medical treatment in the case of a serious allergic reaction, which can cause trouble breathing or swallowing, a weak pulse, dizziness, and full-body redness and warmth. 

Avoiding triggers 

There are currently no treatments for alpha-gal syndrome, Karim said. Monitoring food intake, instead, is key, he noted. 

“Don’t eat beef, avoid it and other red meats,” he said. “Slowly, symptoms will go away.” 

He said avoiding red meat is a difficult task, especially as some foods containing it may not be labeled correctly or properly. Additionally, fumes from red meat — such as smoke from cooking a steak in a restaurant kitchen — could be enough to set off a reaction in an affected person.  

Jefferson Van Drew, a U.S. representative from New Jersey, introduced a bill in August 2024 that would amend the Federal Food, Drug, and Cosmetic Act to add alpha-gal to the definition of “major food allergen.” If enacted, the Alpha-Gal Allergen Inclusion Act would require packaged foods with alpha-gal to be clearly labeled. 

Supporters of the bill, including the Alpha-gal Foundation and the Alpha-gal Alliance Action Fund, say the legislation “will help the growing alpha-gal community to easily identify unsafe foods.” 

Prevention is paramount 

Karim said, to avoid acquiring the allergy, people should exercise caution during outdoor activities.  

“Use repellant to make sure ticks will not bite,” he said. 

The Mayo Clinic report says that insect repellant with a 20% or higher concentration of the ingredient DEET is helpful in avoiding tick bites. Clinic staff also recommend covering up all body parts when in wooded or grassy areas and tick-proofing yards by clearing brush and leaves.

“Check yourself, your children and your pets for ticks” after spending time in wooded or grassy areas is another recommendation from the clinic. 

If a tick is found, it is important to remove it “with tweezers as soon as possible,” according to the clinic’s report: “Gently grasp the tick near its head or mouth. Don’t squeeze or crush the tick. Pull it off with a careful, steady grip. Once you’ve removed the entire tick, throw it out. Put on an antiseptic where it bit you.” 

An optimistic outlook 

Karim said that his lab is hard at work answering many of the unknowns surrounding the allergy. 

“There is lots we don’t know,” he said, pointing out many unanswered questions surrounding alpha-gal syndrome. 

For example, the professor and his colleagues are unsure about environmental or genetic predispositions to the allergy. They also do not yet know the biological and functional significance of alpha-gal to ticks. 

Karim said he remains optimistic that scientists will break the mysteries behind the allergy and solve the suffering involved with alpha-gal syndrome. 

“The most important thing is … we want to develop some immunotherapy drugs so the people can be cured,” he said.