Tick-Borne Meat Allergy: Many Carry Alpha-Gal Antibodies Without Symptoms

WEDNESDAY, July 22, 2026 (HealthDay News) — Many more Americans than previously estimated carry antibodies related to a meat allergy caused by tick bites, a new study says.

Nearly 1 in 4 adults in states with the highest rates of alpha-gal syndrome carry antibodies related to the condition, researchers reported recently in Morbidity and Mortality Weekly Report.

These results indicate that tick bites won’t necessarily lead to the full-fledged allergic reaction characterized by alpha-gal syndrome, researchers said.

Symptoms from an alpha-gal allergic reaction can include hives, swelling, nausea, vomiting, abdominal pain, diarrhea or even life-threatening anaphylactic shock, researchers said.

“Many individuals may be sensitized to alpha-gal and have detectable antibodies without experiencing any symptoms,” lead researcher Dr. Eleanor Saunders said in a news release. She’s an assistant professor of medicine in infectious diseases at the University of North Carolina at Chapel Hill.

Alpha-gal syndrome occurs when a tick bite causes a person’s immune system to develop an allergic reaction to a sugar molecule found in beef, pork or lamb called galactose-alpha-1,3-galactose, or alpha-gal, researchers said.

In the United States, the syndrome is commonly associated with lone star tick bites, researchers said.

To assess the risk of alpha-gal syndrome, researchers tested 3,000 blood samples collected between November 2024 and April 2025 from residents of 10 states.

Results showed that the percentage of people carrying alpha-gal antibodies was highest in states where lone star ticks are well established.

Arkansas had the highest levels, with nearly 1 in 3 residents (31%) carrying alpha-gal antibodies. Missouri followed with 26% of residents “sensitized” to alpha-gal.

All told, about 1 in 4 people (24%) could be expected to test positive for alpha-gal antibodies across the five states with the highest prevalence — Arkansas, Kentucky, Missouri, Tennessee and Virginia.

These results indicate that relying solely on blood tests might lead to overdiagnosis of alpha-gal syndrome, given that many can carry antibodies without suffering an allergic reaction, researchers said.

Alpha-gal syndrome, or AGS, was estimated to affect up to 450,000 people in the United States in 2022, but this study suggests many more might have had a tick bite and developed antibodies without suffering symptoms related to the syndrome.

“Diagnosis of AGS requires both a compatible clinical history and laboratory evidence,” Saunders said.

Rates of alpha-gal antibodies were higher among folks between 55 and 64 years of age compared to younger people, and men were more likely than women to test positive, researchers said.

People in rural areas also were more likely to carry alpha-gal antibodies, likely reflecting higher levels of tick exposure, researchers said.

Further research is needed to help figure out how many people with alpha-gal antibodies go on to suffer from the syndrome, and why they are more vulnerable, the team concluded.

“Blood donor seroprevalence data provide a valuable picture of where alpha-gal exposure is occurring,” Saunders said. “These findings support a geographically focused approach to surveillance, prevention and provider education in communities at greatest risk.”

More information

The U.S. Centers for Disease Control and Prevention has more about alpha-gal syndrome.

SOURCE: UNC Health, news release, July 16, 2026