CDC Warns 400,000 Americans May Be Allergic to Red Meat Due to Tick Bites

According to two new reports from the Centers for Disease Control and Prevention (CDC), over 100,000 people throughout the United States may have developed an allergy to red meat due to a complicated reaction caused by tick saliva. In one report, the CDC said that at least 100,000 people have been diagnosed with the illness, called alpha-gal syndrome, (AGS) since 2010, but the agency also suggested that the true number may be significantly higher.

The Cleveland Clinic explains that some ticks have a sugar molecule called alpha-gal in their saliva, that can enter a human’s bloodstream if they get bitten by one of these ticks. When the alpha-gal enters the bloodstream, it can cause an allergic reaction. That reaction may be repeated when the affected person consumes foods that contain alpha-gal, including red meat.

Alpha-gal is found in most mammalian meats, including beef, lamb, pork, rabbit, and venison, and in products derived from mammals, including gelatin and cow’s milk. The CDC also notes that certain cuts of meat — including organ meats, sweetbreads, and Rocky Mountain or prairie oysters, — often contain higher amounts of alpha-gal than others. The alpha-gal molecule is not present in poultry, eggs, fish and seafood, reptiles, or fruits and vegetables.

The CDC believes that AGS is primarily caused by the bite of the lone star tick, but adds that other tick species “have not been ruled out." The agency notes that people who have confirmed or suspected cases of AGS have been located in states and locations where lone star ticks are prevalent, including Arkansas, Kentucky, Missouri, and the easternmost county of Long Island, New York. 

After an initial tick bite, the symptoms of AGS may present themselves between two and six hours after eating meat or dairy, and the allergic reactions may include hives or a rash; nausea or vomiting; heartburn or indigestion; diarrhea; cough or shortness of breath; or severe stomach pain. There is no cure or treatment for AGS, but many people with confirmed cases have reported a decrease in symptoms when they remove red meat and dairy products from their diets.

As the Associated Press reports, one of the CDC’s recently released studies was an analysis of the lab results from people who had been tested for alpha-gal antibodies. The report revealed that there have been 110,229 suspected cases of AGS in the U.S. between 2010 and 2022, The second report detailed the results of a survey of 1,500 healthcare providers, who were asked about their knowledge and understanding of AGS.

Of those surveyed, 42% said that they were not aware of AGS, while another 35% reported that they were “not confident in their ability” to diagnose the syndrome or to “manage” those who had contracted the illness. Of the surveyed providers, 48% also responded that, when presented with a suspected AGS case, they would not know what diagnostic tests to order.

As a result, the report’s authors suggested that four times as many Americans — over 400,000 — may have actually developed AGS since 2010.