Far more people may be at risk for alpha-gal syndrome, the tick-borne illness that triggers an allergy to red meat, than previously thought.Limited time: Save 25% on NBC News subscriptionGet exclusive reporting, live Q&As and ad-free reading.Nearly a quarter of adults in five states where lone star ticks are prevalent are estimated to show signs that they’ve been bitten, according to new research published Thursday by the Centers for Disease Control and Prevention.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.
In some people, that triggers an allergic reaction to red meat, as well as meat byproducts like gelatin.The new research is an analysis of 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, according to the analysis.The presence of alpha-gal antibodies means that a person has been exposed to the alpha-gal molecule at some point.Those antibodies don’t mean a person has alpha-gal syndrome, or should even be tested for it, said lead study author Dr.
Eleanor Saunders, an infectious disease specialist at the University of North Carolina-Chapel Hill.It simply indicates that they’ve likely been bitten by a tick that could make them sick.The report isn’t intended “to create vegetarians out of people who don’t want to be them,” Saunders said.
“We are concerned about overdiagnosis.” However, Saunders said it’s possible that those ...