Study results released Thursday by the CDC find that the highest prevalence of people with alpha-gal antibodies is in Arkansas, Kentucky, Missouri, Tennessee and Virginia.
Alpha-gal is a molecule found in most mammals but not in people. It’s transferred to humans by tick bites.
Alpha-gal syndrome or AGS is an allergy to mammalian meat, dairy and by-products.
When a tick bites a person and transfers-alpha gal, the body perceives it as a threat and produces antibodies. Those antibodies can trigger a severe allergic reaction when the person later eats beef or pork.
It's important to note that people can have alpha-gal antibodies in their blood but not have AGS.
The study during 2024-2025 tested 3,000 blood samples from blood donors in 10 states. There was a 24% prevalence rate in the top five states.
The CDC says, because only a small number of people with alpha-gal antibodies have AGS, health care providers should only test patients with AGS symptoms. Those include hives, itching or rash, gastrointestinal symptoms, swelling of the lips, face, throat or eyelids and respiratory symptoms such as wheezing and shortness of breath.
