Emerging tick bite-associated meat allergy potentially affects thousands, CDC says

Nearly half a million people are estimated to have been affected by a potentially life-threatening allergic condition called alpha-gal syndrome that is caused by a tick bite, according to two new reports from the Centers for Disease Control.

Between 2010 and 2022, there were more than 110,000 suspected cases of alpha-gal syndrome identified, the CDC says, which is a potentially life-threatening allergic reaction to alpha-gal, a sugar found in red meat and other products. New reports have now estimate that as many as 450,000 people might have been affected by alpha-gal syndrome in the U.S.—more than four times what was originally identified.

This discrepancy is believed to be due some individuals with alpha-gal syndrome not getting tested as the diagnosis of alpha-gal syndrome requires a positive diagnostic test and a clinical exam, the CDC said.

“The burden of alpha-gal syndrome in the United States could be substantial given the large percentage of cases suspected to be going undiagnosed due to non-specific and inconsistent symptoms, challenges seeking healthcare, and lack of clinician awareness,” said Dr. Johanna Salzer, senior author on both papers recently released by the CDC.

Alpha-gal is a sugar found in meat from mammals, like red meat from pork, beef, rabbit, lamb, venison, etc., and products made from mammals, such as gelatin, cow’s milk, milk products, and some pharmaceuticals. The syndrome is an allergic reaction to the alpha-gal sugar found in those products, and the CDC says growing evidence shows the syndrome is primarily associated with the bite of a lone star tick in the U.S. Other types of ticks have not been ruled out. Localities in the southern, midwestern, and mid-Atlantic regions of the U.S. identified more people who tested positive.

While local health departments don’t track alpha-gal syndrome, some say there is reason to believe that tick-borne diseases are on the rise in general. The Clark County Combined Health District has counted 10 cases of Lyme disease so far in Clark County this year.

Lyme disease is an illness caused by bacteria found in certain ticks, which can cause a rash and flu-like symptom. That is more than in the previous four years combined, the health district said. Montgomery County has had one reported case of Lyme disease this year.

There are a wide range of symptoms for alpha-gal syndrome, including hives or 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 eye lids; dizziness or faintness; or severe stomach pain, according to the CDC.

Symptoms also typically appear between two and six hours after eating or being exposed to food or products containing alpha-gal. Alpha-gal syndrome is diagnosed by an allergist or other health care provider and requires a thorough history with compatible symptoms, and diagnostic testing for antibodies specific to alpha-gal, the CDC said. A health care provider may also recommend allergy skin testing for a patient.

One of the recent studies released by the CDC shows limited knowledge from health care providers on the topic of alpha-gal syndrome. In one study, nearly half of, or 42% of, the 1,500 participants—including general practitioners, internists, pediatricians, nurse practitioners, and physician assistants—had not heard of alpha-gal syndrome. Another 35% were not confident in their ability to diagnose or manage patients with alpha-gal syndrome, the CDC study said.

“Alpha-gal syndrome is an important emerging public health problem, with potentially severe health impacts that can last a lifetime for some patients,” said Dr. Ann Carpenter, epidemiologist and lead author of that study. “It’s critical for clinicians to be aware of (alpha-gal syndrome) 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.”

In another study, researchers found the number of cases of alpha-gal syndrome have increased substantially since 2010, and states with established populations of lone star ticks were most affected, the CDC found.

Avoiding ticks can help protect against getting alpha-gal syndrome from a tick, as well as protect against tick-borne illnesses like Lyme disease.

Preventing tick bites is important and may reduce your chances of developing (alpha-gal syndrome),” said Allison Combs, public information officer with the Warren County Health District

When outdoors, people should avoid grassy, brushy, and wooded areas, where ticks may be found.

“If you’re walking into the woods on a trail, you want to stay in the center of the trail,” said Dan Suffoletto, public information manager for Public Health - Dayton and Montgomery County. “You want to use insect repellant approved by the EPA and is labeled for protection against ticks.”

People can also treat their clothing or other hiking gear with 0.5% permethrin or buy permethrin-treated clothing and gear. Permethrin is an insecticide that kills or repels mosquitoes, according to the CDC, and permethrin-treated clothing can provide protection after multiple washings.

When returning from a hike or being outdoors, people should check for ticks.

“When you’re out in an area where there might be ticks, you want to check yourself for ticks when you come in,” Suffoletto said. “You can shower afterwards to help remove them and to help identify whether you have them at all. If you do have a tick on you, you can remove it, but you have to carefully remove it with fine-tipped tweezers and pull it out of your skin by its head.”

The Warren County Health District can also send ticks off for identification to the Ohio Department of Health, Combs said, which may be helpful if someone is unsure if they or someone else has been bit by a lone star tick. If someone needs to drop off a tick, they should call the health district at 513-695-1498.

“WCHD also offers tick pick kits, where we give free tweezers and tick identification and removal instruction cards, so people are able to properly remove ticks from themselves or any other people and pets,” Combs said.

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