Today in Morbidity and Mortality Weekly Report, authors from the US Centers for Disease Control and Prevention (CDC) describe alpha-gal syndrome (AGS), a growing tick bite-associated allergy to mammal meat and milk.
The condition can be life-threatening and is characterized by a hypersensitivity to the sugar molecule galactose-alpha-1,3-galactose (alpha-gal). Cases are increasing across the country along with the number of tests performed and suspected AGS cases. The number of persons who received positive test results jumped from 13,371 in 2017 to 18,885 in 2021.
But despite growing incidence, in a survey of 1,500 US healthcare providers (HCPs), 42% said they had never heard of the condition. Among those who had heard of the condition, 35% said they were not confident in their ability to diagnose the allergy, and only 55 clinicians (6%) said they had treated 5 or more alpha-gal patients.
The condition is primarily associated with the bite of the lone star tick (Ambylomma americanum) in the United States, with most cases recorded in the South and Midwest.

Allergic symptoms develop within 2 hours of eating something containing alpha-gal and range from mild (rash) to severe (anaphylaxis).
"More than one half of the respondents (502; 58%) correctly identified topics on which to counsel AGS patients, such as tick bite prevention, eliminating red meat from their diet, exercising caution when receiving new medications and vaccines, and recognizing and managing anaphylaxis," the authors said.
More clinician education is needed, the authors concluded. "The lack of HCP knowledge of AGS is likely to lead to undertesting, further hampering knowledge of the national prevalence of AGS," they said.