A recent report from the CDC reveals that Virginia, and Charlotte County, in particular, has the highest number of people testing positive for alpha-gal syndrome (AGS), a food allergy associated with tick bites.

AGS is caused by ticks transmitting a sugar called alpha-gal, which is found in all mammals except humans. This means that people with AGS can potentially have allergic reactions hours after consuming meat or dairy products.

Symptoms of AGS include recurring vomiting, diarrhea, and abdominal pain, which can be life-threatening.

In the United States alone, there have been over 90,000 documented cases of AGS between 2017 and 2022. Each year during the CDC study, approximately 30,000–70,000 persons received testing, although testing peaked at 66,106 persons in 2021

Test results from 79% of persons with available geographic data were used for map generation according to the CDC.

The highest number of suspected AGS cases per 1M PPY were in Charlotte County with a total of 12,273 and Muhlenberg, Kentucky with 6,107.

Alpha-gal linked to tick bites

The majority of these cases are believed to be associated with tick bites, particularly from the lone star tick, in the southern, midwestern, and mid-Atlantic regions of the country.

From January 1, 2017– December 31, 2022, a total of 357,119 tests were submitted from U.S. residences corresponding to 295,400 persons who were included in this analysis.

According to the CDC report among these, 235,752 (80%) reported state of residence, and 233,521 (79%) reported zip code of residence.

The majority of persons who received testing received one test during the study period, but 36,257 persons (12.3%) received more than one test.

Overall, 188,532 (63.8%) persons receiving testing were female, but 42% of men received a positive test result, compared with 24% of women.

Despite the growing number of AGS cases, there is currently no known treatment or cure available. Diagnosis of AGS requires testing and a clinical examination, but unfortunately, many individuals who experience symptoms are not tested.

It is estimated that since 2010, as many as 450,000 people may have been affected by AGS.