Up to 450,000 Americans may have been affected by a potentially life-threatening red meat allergy caused by ticks as many doctors remain unaware of what it is or how to treat it, according to the Centers for Disease Control and Prevention.
In new reports released on Thursday, the CDC found that between 96,000 and 450,000 Americans since 2010 may have been affected by alpha-gal syndrome. The syndrome, also known as a red meat allergy or tick-bite meat allergy, stems from alpha-gal, a sugar molecule not naturally present in humans. Instead, it is found in meat including pork, beef, rabbit, lamb and venison, as well as products made from mammals including gelatin and milk products.
“Because the diagnosis of alpha-gal syndrome requires a positive diagnostic test and a clinical exam, and some individuals with alpha-gal syndrome may not get tested, it is estimated that as many as 450,000 people might have been affected by AGS in the United States,” the CDC said, adding. “Of those aware of AGS, knowledge about diagnosis and management is low.”
Growing evidence suggests that AGS is primarily associated with saliva from the lone-star tick, which the CDC has described as a “very aggressive” tick that bites humans and is widely distributed across south-eastern and south-central states. According to the CDC, localities in the southern, midwestern and mid-Atlantic regions of the US have identified more people who tested positive with AGS.
“Persons with suspected AGS were predominantly located in areas where the lone-star tick is known to be established or reported, particularly throughout Arkansas, Kentucky, Missouri, and Suffolk county, New York,” said the CDC.
From 2017 to 2021, there was an annual increase in positive AGS test results across the country, with over 90,000 suspected cases identified during that time, according to the reports. The number of new suspected cases increased by approximately 15,000 annually during the study.
Ann Carpenter, a CDC epidemiologist and lead author of one of the reports, said AGS is an “important emerging public health problem, with potentially severe health impacts that can last a lifetime for some patients”.
Although people of all ages can develop AGS, most cases have been reported in adults, according to the CDC. Although additional data and research is needed to understand the exact number of people affected by AGS, the CDC has listed various symptoms that may point to the syndrome.
Those include 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 eyelids, dizziness or faintness, or severe stomach pain. Symptoms typically appear two to six hours after consuming food or being exposed to products that contain alpha-gal such as gelatin-coated medications.
Symptoms can range from mild to severe to life-threatening. In some cases, individuals can experience anaphylaxis, a potentially life-threatening reaction that occurs when an over-release of chemicals puts the person into shock, in turn impacting multiple organ systems.
Despite the hundreds of thousands of individuals affected by AGS, healthcare providers in the US “have low awareness of AGS”, said the CDC. According to one of the reports, 42% of 1,500 doctors surveyed had never heard of AGS while 35% reported that they were “not too confident” in their ability to diagnose AGS or to manage patients with AGS.
“It’s important that people who think they may suffer from AGS see their healthcare provider or an allergist, provide a detailed history of symptoms, get a physical examination, and a blood test that looks for specific antibodies (proteins made by your immune system) to alpha-gal,” said Johanna Salzer, another author on the reports.
The CDC has recommended various steps for individuals to take to prevent tick bites and, in turn, AGS. Before going outdoors, individuals should avoid grassy, brushy and wooded areas where ticks may be found, walk in the center of trails, and treat clothing and gear with the insecticide permethrin or buy pre-treated items.
• This article was amended on 28 July 2023 to remove a picture of a deer tick and replace it with one of a lone-star tick.
