Meat Allergy Cases Linked To Tick Bites May Be Growing In WI, CDC Says

WISCONSIN — The number of Wisconsinites who might be living with a tick-triggered meat allergy is likely greater than what official numbers suggest, according to a pair of studies released Thursday by the Centers for Disease Control and Prevention.

The first study estimated as many as 110,000 Americans developed an allergy to red meat between 2010-2022 because of alpha-gal syndrome, or AGS. But, the CDC says the true number of Americans who have developed the allergy may be closer to 450,000. That would make it the 10th most common food allergy in the country, Dr. Scott Commins, a University of North Carolina researcher who co-authored both papers, told The Associated Press.

The number of people testing positive for alpha-gal antibodies rose from about 13,000 in 2017 to 19,000 in 2022, according to one of the studies. In all, more than 90,000 suspected cases were identified during the study period. During that timeframe in Wisconsin, cases have popped up around the state, especially in northern Wisconsin with some far-north counties showing a rate between 11-87 cases per million people, according to the CDC.

Central Wisconsin and western parts of the state including Dane County had fewer suspected cases, less than 11 per million people. Meanwhile in southeast Wisconsin, the rate is significantly lower with most counties showing 0 cases and Milwaukee County showing fewer than 11 per one million people.

Scientists discovered in 2011 that the alpha-gal sugar could be spread through tick bites, tying it to the lone star tick, which is common in the eastern and southern United States. Lone star ticks are somewhat present in Wisconsin, but a flyer from the Department of Health Services noted they are rare.

The increases are due in part to the expanding range of lone star ticks, but also because doctors are testing more for the antibody. But many aren’t. In a survey of 1,500 health care workers last year, 78 percent said they had little or no knowledge of the syndrome, and only 5 percent said they felt very confident they could diagnose it.

Dr. Ann Carpenter, an epidemiologist and lead author of one of the papers, called alpha-gel syndrome “an important emerging health problem, with potentially severe health impacts that can last a lifetime for some patients.”

“It’s critical for clinicians to be aware of AGS, so they can properly evaluate, diagnose, and manage their patients and also educate them on tick-bite prevention to protect patients from developing this allergic condition,” Carpenter said in a news release announcing the studies.

Health officials said they aren’t aware of any confirmed deaths related to the allergy.

The AGS reaction occurs when an infected person eats beef, pork, venison or other meat from mammals — or ingests milk, gelatin or other mammal products. It’s not caused by a germ but by a sugar, alpha-gal, that is in meat from mammals — and in tick spit. When the sugar enters the body through the skin, it triggers an immune response and can lead to a severe allergic reaction.

People who have been infected usually notice symptoms within two and six hours after eating food or ingesting other products containing alpha-gal, including gelatin-coated medications.

Symptoms include hives or an itchy rash; nausea or vomiting; heartburn or indigestion; diarrhea; cough; shortness of breath or difficulty breathing; drop in blood pressure; swelling of the lips, throat, tongue, or eyelids; dizziness or faintness; or severe stomach pain.

CDC officials urged anyone who thinks they may be infected to see a doctor or allergist and also emphasized the importance of preventing tick bites.

The Associated Press contributed reporting.