Mosquito-borne diseases and control (5)Vector-borne infectious diseases (4)Leptospirosis research and findings (4)Food Allergy and Anaphylaxis Research (3)Rabies epidemiology and control (3)
Saunders EF, Taylor ML, Jones ES, Biggerstaff BJ, Vorobiov JM, et al.
MMWR. Morbidity and mortality weekly report •
Alpha-gal syndrome (AGS) is an emerging, noninfectious tickborne disease characterized by an allergic reaction to galactose-α-1,3-galactose (alpha-gal), an oligosaccharide found in red (mammalian) meat and other mammalian products such as dairy and gelatin. As of 2022, AGS was estimated to affect up to 450,000 persons in the United States (1). Anaphylactic AGS reactions can be fatal, and AGS allergic reactions encompass a range of symptoms including urticaria, angioedema, wheezing, and gastrointestinal distress. AGS is primarily managed through an avoidance diet. The U.S. geographic distribution of AGS is closely associated with the range of the lone star tick (Amblyomma americanum); bites from this tick introduce alpha-gal through its saliva, which can trigger the allergy. Diagnosis of AGS requires both the presence of clinically compatible symptoms and the detection of serologic immunoglobulin E (IgE) antibodies against alpha-gal. Persons can have alpha-gal-specific IgE antibodies without clinical symptoms. The proportion of persons in the United States who are seropositive for alpha-gal IgE is unknown. To better understand the distribution and seroprevalence of alpha-gal IgE among U.S. adults, 3,000 serum samples collected during November 2024-April 2025 from blood donors living in 10 states were tested for the presence of alpha-gal IgE antibodies. States previously reported to have high numbers of suspected AGS cases were found to have correspondingly high seroprevalences. Among the 10 states, the highest estimated seroprevalences among persons aged ≥16 years were detected in Arkansas (31.2%) and Missouri (26.0%). These findings can guide the development of surveillance systems for AGS and help identify regions at increased risk.
Taylor ML, Kersh GJ, Salzer JS, Jones ES, Binder AM, et al.
Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology •
Alpha-gal syndrome (AGS) is an allergy to galactose-α-1,3-galactose (alpha-gal), a carbohydrate found in most mammals. Evidence indicates that AGS develops after a tick bite, and in the United States, AGS is most associated with bites from Amblyomma americanum (lone star tick); however, not all persons bitten by ticks develop clinical AGS. To investigate intrinsic risk factors associated with the development of AGS. We performed a case-control study among adults presenting for diagnosis or management of AGS at an allergy clinic in North Carolina during 2019 to 2020 and compared them with controls enrolled from 2 nearby internal medicine clinics. A questionnaire gathered epidemiologic and tick exposure data, and blood was obtained for alpha-gal-specific IgE and other testing. The 82 enrolled case patients and 191 controls did not differ significantly by age or sex. Case patients were more likely than controls to have A or O blood types (non B-antigen), have experienced childhood allergies, and have a family history of AGS and other food allergies. Case patients were also more likely to report experiencing long healing times for insect bites or stings and a family history of allergy to stinging or biting insects. This study suggested that intrinsic factors contribute to risk of developing AGS. Some traits are genetic, but common behaviors among households and family units likely also contribute. Identification of these risk factors can inform personal risk, aid health care providers in understanding susceptible populations, and contribute to ongoing understanding of AGS epidemiology.