Millions more Americans may be at risk of developing Alpha-gal syndrome (AGS). This tick-borne allergic condition can occur after just one or two tick bites and can lead to severe allergic reactions to red meat. Reports released by the Centers for Disease Control and Prevention (CDC) just a few weeks ago confirmed that this allergy is indeed ascending, skyrocketing across the United States. Furthermore, evidence has recently surfaced that even more species of ticks than originally thought are able to cause AGS.
Historically, the main vector of AGS many scientists have focused on are bites from the lone star tick (Amblyomma americanum). Emerging data indicates that blacklegged ticks (Ixodes scapularis) may play a significant role in triggering this allergic reaction. As alarming as the CDC’s findings may be, they highlight an important truth. Healthcare providers and the general public need to be more informed about the potential harm from various tick species.
Now the CDC has confirmed at least three cases of AGS in individuals who were bitten by blacklegged ticks. That’s because these ticks are much more prevalent in the Upper Midwest, East Coast, and the South. Before this, these ticks had only been associated with AGS cases in other countries, like in Australia and Europe. Ixodes pacificus ticks range along the Pacific Coast from California north into Washington state. These ticks have been associated with cases of AGS.
Understanding Alpha-gal Syndrome
Alpha-gal syndrome occurs when an individual develops an allergy to alpha-gal. This sugar molecule is present in red meat and other products made from mammals. The allergy develops for the most part following a tick bite. When the tick bites you, it releases alpha-gal in your bloodstream — your immune system then has to kick into gear. Symptoms can vary widely among individuals. While some experience severe reactions after consuming red meat, others may only exhibit gastrointestinal symptoms.
CDC’s initial case study uncovered the tale of a 61-year-old woman from Washington. She acquired AGS from a tick bite. Further testing showed that her blood had extremely high levels of IgE antibodies that are related to allergic response. After she received her diagnosis, she was instructed to remove beef, pork, lamb, and certain dairy products from her diet altogether. Over the years, several patients have reported experiencing a decrease in their IgE levels. This progress has allowed them to bring meat and dairy back into their lives!
“When that person eats red meat—like beef, pork, venison, or lamb—or is exposed to other mammal-derived products like gelatin or dairy, or some medications, their immune system recognizes the alpha-gal in those products and overreacts,” – Dr. Pritt
According to CDC estimates, as many as 450,000 Americans from 2010 to 2022 have been affected by AGS. Until recently, most cases had been limited to states like Missouri, Arkansas, Tennessee, Kentucky, Virginia and North Carolina. As indicated by the recent results, the range of AGS is likely extending beyond these historically established perimeters.
Emerging Evidence on Tick Species
Our understanding of tick species responsible for AGS has changed considerably in recent years. Until recently, researchers have mostly studied the lone star tick. Now, they are finding that other tick species can cause the syndrome.
These findings from the CDC identify blacklegged ticks as a possible vector of AGS cases within the U.S. This leads to another critical question — where are these ticks geographically distributed? This is particularly dire for the future of public health and awareness campaigns to help people avoid tick bites.
“These findings help to support the idea that the geographic distribution and species of ticks that carry alpha-gal are more widespread than we have found in the past,” – Steele
“These case reports highlight that patients in areas outside the established range of the lone star tick may also be at risk, although the evidence continues to support that in the U.S., most alpha-gal syndrome patients develop the allergy after experiencing a bite from a lone star tick,” – Dr. Salzer
Implications for Public Health
As alpha-gal syndrome becomes more widespread, the need for an immediate public health response is evident. We need to raise awareness about tick bites and the havoc they can wreak. Health officials are encouraging residents to protect themselves from tick bites while enjoying the outdoors. This has developed as more tick species are being implicated in cases of AGS. To prevent tick bites, be sure to wear protective clothing and use insect repellent with DEET. After being in wooded or grassy areas, do full-body tick checks.
Further, the CDC’s findings on AGS draw attention to the critical need for all healthcare providers to remain vigilant in diagnosing and treating AGS. This is especially critical in areas where AGS has not been historically acknowledged. Patients who present with allergy symptoms after eating red meat should be screened for history of engaging with ticks.
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