It might sound like something out of PETA’s handbook of master plans, or a scheme by evil scientists fed up with climate change deniers. Either way, hundreds of people across the United States can no longer eat red meat because of a tick.

Scientists became aware of the effects of the Lone Star tick, named after barbecue-loving Texas, a few years ago. But only recently are doctors seeing a surge of people across the country who suddenly develop meat allergies, landing them in the hospital after eating a burger or, in one case, a Twinkie. (It contains beef fat.)

“Why would someone think they’re allergic to meat when they’ve been eating it their whole life?” said Long Island, N.Y., allergist Erin McGintee, telling NBC News that she’s seen 200 cases. “It is bizarre. It goes against almost anything I’ve learned as an allergist.”

The Lone Star tick carries alpha-gal, a sugar found in red meat. It’s harmless when humans ingest it by eating beef, pork, rabbit, or venison. But when it comes from a tick bite, the body’s immune system goes on high alert—causing a severe allergic reaction that could be deadly. The victim suffers from hives and itching, and his or her throat could swell shut. Some people who have been bitten carry EpiPens (epinephrine shots) in case of another attack.

Lone Star ticks have spiked in number over the past two to three decades. Though they’re mainly found throughout the Eastern and Southern states, the critters have been reported as far west as Oklahoma and Texas. The Centers for Disease Control and Prevention recommends steering clear of brushy areas and dense woods to avoid getting bitten.

Doctors are still figuring out how long the allergy could last. Some patients recover, while others remain allergic. Understandably, those who have suffered serious reactions resist eating red meat again.