Alpha-gal syndrome, a tick-borne illness that triggers an allergy to red meat, may affect more people than previously thought. According to new research published by the Centers for Disease Control and Prevention (CDC), nearly a quarter of adults in five states where lone star ticks are prevalent show signs that they’ve been bitten by a tick and exposed to alpha-gal.
What is Alpha-Gal Syndrome?
Alpha-gal syndrome is caused by ticks, usually the lone star tick, that have previously fed on mammals like cows, deer, goats, and pigs. Those animals have a specific sugar molecule in their blood called alpha-gal. When those ticks go on to bite humans, they can transmit the molecule to people, triggering an allergic reaction to red meat and meat byproducts like gelatin.
The new research analyzed blood samples from 3,000 adults in 10 states who donated blood from November 2024 to April 2025. People living in states already known to have high levels of lone star ticks were much more likely to have evidence that they’ve already been bitten by a tick and exposed to alpha-gal. About 24% of adults in five states — Arkansas, Kentucky, Missouri, Tennessee, and Virginia — were estimated to have antibodies to alpha-gal.
Symptoms and Risks
Symptoms of alpha-gal syndrome usually don’t appear right away and can include hives, itching, and difficulty breathing. The presence of alpha-gal antibodies doesn’t mean a person has alpha-gal syndrome, but it does indicate that they’ve likely been bitten by a tick that could make them sick. The CDC has previously estimated that about 450,000 people in the U.S. could have alpha-gal syndrome, but the true prevalence is unknown.
The lone star tick isn’t the only one that can cause alpha-gal syndrome. Black-legged ticks, Cayenne ticks, and Asian longhorned ticks can also transmit the sugar molecule to people. As winters become warmer, deer populations move into new areas of the country, and the ticks that feed on those animals go with them, increasing the risk of alpha-gal syndrome.
Original reporting: Dallas TX News (HLL/CB) — read the source article.
