03/06/26 Public Health Education Topic: Alpha-Gal Syndrome

Per CDC Español

Key points

• Alpha-gal syndrome (AGS) is a serious, potentially life-threatening allergy to alpha-gal that can develop after a tick bite.

• Alpha-gal is a molecule found in most mammals, such as cows and pigs, but not in people.

• People with AGS can have an allergic reaction after eating red meat or being exposed to products containing alpha-gal.

• The best way to protect yourself and your family from AGS is to prevent tick bites.

Risk factors

AGS is caused by tick bites, though more research is needed to understand the role ticks play in causing AGS. In the United States, AGS is primarily associated with the bite of a lone star tick, and less commonly by the bite of a blacklegged tick or a western blacklegged tick. In other countries, other tick species have been linked to AGS. In the United States, not every person bitten by a lone star, blacklegged, or western blacklegged tick will develop AGS. The reason why certain people develop AGS and others do not, is not known.

Most cases of AGS have been reported in adults, but people of all ages can develop AGS.

Most reported cases of AGS in the United States occur in South, East, and Central states. These are the areas where most lone star ticks are found.

Prevention

The best way to protect yourself and your family from developing AGS is to prevent tick bites.

To learn more please visit: About Alpha-gal Syndrome | Alpha-gal Syndrome | CDC