A meat allergy caused by tick spit is getting more common, CDC says

More than 100,000 people in the U.S. have become allergic to red meat since 2010 because of a weird syndrome triggered by tick bites, according to a government report released Thursday.

More than 100,000 people in the U.S. have become allergic to red meat since 2010 because of a weird syndrome triggered by tick bites, according to a government report released Thursday. But health officials believe many more have the problem and don't know it.

A second report estimated that as many as 450,000 Americans have developed the allergy. That would make it the 10th most common food allergy in the U.S., said Dr. Scott Commins, a University of North Carolina researcher who co-authored both papers published by the Centers for Disease Control and Prevention.

Health officials said they are not aware of any confirmed deaths, but people with the allergy have described it as bewildering and terrifying.

"I never connected it with any food because it was hours after eating," said one patient, Bernadine Heller-Greenman.

The reaction, called alpha-gal syndrome, 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.

Scientists had seen reactions in patients taking a cancer drug that was made in mouse cells containing the alpha-gal sugar. But in 2011 researchers first reported that it could spread through tick bites, too.