As many as 450,000 Americans could have contracted an allergy to red meat that’s linked to tick bites, according to a report from the Centers for Disease Control and Prevention that calls for new efforts to educate doctors and the public about the condition.

Americans are familiar with Lyme disease, the most common tick-borne illness, as cases have skyrocketed in recent years. But as climate change and increased development have led to a growing prevalence of ticks in more parts of the country, the numbers of other tick-borne diseases have spread, too.

Testing identified more than 110,000 suspected cases of alpha-gal syndrome between 2010 and 2022, according to research published Thursday in the CDC’s Morbidity and Mortality Weekly Report. People with alpha-gal syndrome are allergic to a sugar found in red meat and some animal products, with symptoms ranging from hives to life-threatening anaphylactic reactions.

But since the disease often goes undiagnosed, the researchers wrote, the true number of cases could be much higher. They estimated that as few as 20% of affected people get tested, meaning the true number could be as high as 450,000.

Cases were highest in the habitat of the lone star tick, including in Arkansas, Kentucky, Missouri and part of New York, researchers found when they looked at positive test results from 2017 to 2022. The species doesn’t harbor Lyme disease, but it’s been linked to alpha-gal syndrome, the rare but dangerous Heartland virus and a bacterial infection called ehrlichiosis.

Yet, while cases are on the rise, in a CDC survey of health-care providers, 40% said they’d never heard of the condition.

“It’s critical for clinicians to be aware of AGS so they can properly evaluate, diagnose, and manage their patients,” said Ann Carpenter, a CDC epidemiologist and one of the report’s authors, in a statement.

There’s no known cure, though the condition sometimes goes away on its own. Doctors manage it by helping patients avoid foods containing the problematic sugar.

Doctors should also educate people about tick bites so they don’t develop the condition in the first place, Carpenter added. The CDC recommends that people treat clothing and camping gear with an insecticide called permethrin, as well as checking for ticks after coming back from the outdoors.