Meat allergy in the US is slowly being eradicated by fire ants

The "alpha-gal" meat allergy is caused by the bite of the lone star tick.

Ant (illustrative) (photo credit: REUTERS)
Ant (illustrative)
(photo credit: REUTERS)
Invasive fire ants are limiting the spread of a dangerous meat allergy across the United States, researchers at the University of Virginia School of Medicine have found.
The unexpected finding came about during a study of the "alpha-gal" meat allergy, which causes sufferers to experience potentially severe allergic reactions to mammalian meat products. The allergy is spread by the bite of the lone star tick, and is common throughout the Southeast, the Mid-Atlantic, and the Midwest, but is rare along the Gulf coast and in Texas.
The researchers mapped the data, and were led to an unusual theory: fire ants.
“We did not set out to study fire ants, but when the number of alpha-gal cases in the Gulf Coast was consistently lower than we expected, the fire ant emerged as an interesting explanation,” said UVA researcher Behnam Keshavarz, PhD, a co-first author of a new scientific paper outlining the discovery.
The alpha-gal allergy was first identified over a decade ago by UVA allergist Thomas Platts-Mills. Since then, he and his colleagues have investigated the process by which the tick's bite causes people to develop an allergy to alpha-gal, a sugar present in meat, but little work had been done on the geographic spread of the allergy within the United States.
The team at UVA set out to change that, by surveying allergists across the country to map cases of the allergy. They also tested blood samples in two different geographic locations, to show that the allergy was similar across the country.
They found 14 states in which the allergy was common in a significant percentage of the state, and eleven states in which at least one allergist reported more than 100 cases of alpha-gal in their clinic. However, they also found that six out of ten allergy clinic in Eastern Texas had no cases at all.
Having gathered data from 44 states, the researchers were surprised to see few cases in Texas or the Gulf Coast - surprised because the lone star tick is usually reported on Centers for Disease Control maps of the area.
After considering potential explanations for the omission, the researchers went back to the allergists and surveyed them on allergic reactions caused by fire ants. They overlaid the results, and the results produced a striking inverse relationship: areas with the highest numbers of fire ant allergies were those with the lowest rates of meat allergy.
Their conclusion is that the fire ants are somehow competing with or preying upon the ticks.
The ants were accidentally imported from South America in the 1930s and have been slowly spreading northwards ever since, but while this is good news in terms of limiting the spread of alpha-gal allergy, they are merely being replaced by fire ant allergy cases.
“These are two arthropod-related allergic diseases that are connected with each other,” Platts-Mills concludes. “The situation is unique because we think we can predict how both will change over time.”