Alpha-gal syndrome is an allergy to red meat caused by tick bites. It is most commonly associated with the lone star tick, recently found as far from its usual range in the South as Martha’s Vineyard. Less widely reported is that California’s own western black-legged tick can also trigger the potentially fatal condition.
Two years ago, Laura Hieb, a retired teacher from Jenner, learned about alpha-gal in the most dangerous way.
“I went to a July fourth party. Very upscale. The host bought delicious steaks for everyone,” Hieb said. “I came home around 10:30pm and around 1:30am became violently ill.”
Alpha-gal is a sugar present both in the meat of most mammals, though not humans, and the saliva of certain ticks. When a tick bite elicits an immune response from its human victim with alpha-gal present in the wound, because it is foreign to them, their body learns to treat it as a threat, regardless of the source. Their next exposure to alpha-gal, whether from a tick or a steak, can cause hives, dizziness, vomiting and diarrhea, and in the most severe cases, swelling of the tongue, throat and airway.
“I was rapidly going into anaphylactic shock. I could not breathe; my throat was closing. And of course I was out here in Jenner all alone,” said Hieb, who luckily recognized the symptoms from previous allergic reactions and self-administered Benadryl. “I took maybe five and lay down and tried to focus on breathing. And I made it through.”
Unlike most allergic reactions which take effect almost immediately, AGS symptoms often occur several hours after exposure, complicating diagnosis, delaying or misdirecting treatment. This can also lead to repeated accidental exposures which some evidence suggest results in increasingly severe reactions.
Though the western black-legged tick is found in 56 out of 58 counties, confirmed AGS diagnoses in California are still relatively rare, so meaningful data on the risk-per-bite of developing AGS doesn’t yet exist. Cases as severe as Laura Hieb’s are rarer still. But for those unfortunate few, it is life changing. And so she worries others are being missed.
After Hieb’s physician tested for all the known allergens she was exposed to at the party, to no avail, she solved the puzzle herself. “Within just days, I saw this article in AARP magazine about alpha-gal, so I called the allergist,” Hieb said. The detail that stood out to her was the delayed reaction, along with a tick bite on her back. But until she educated them, her care providers at Kaiser Permanente were completely unaware of the issue.
In fact, of 1,500 medical practitioners surveyed by the CDC, 42% had never heard of AGS and another 35% were not confident in their ability to diagnose or manage AGS patients.
Once AGS develops, lifestyle changes are the only preventative option to date. “I’ve had to change my diet completely,” Hieb said. “I had another scary incident eating at a restaurant because I didn’t realize there was bacon crumbled on my omelette… So now I carry an EpiPen.”
Avoiding alpha-gal is made all the more complicated since it can show up in unexpected places such as cosmetics and medications. Incidentally, it was an alpha-gal-containing cancer drug undergoing a clinical trial that tipped doctors off to the molecule’s deadly potential.
In 2004, a subset of patients receiving Cetuximab had severe allergic reactions on their first dose. Drug allergies usually build up over time. Meanwhile, doctors in the southeastern U.S. were seeing odd, delayed allergic reactions to red meat. University of Virginia allergist Dr. Thomas Platts-Mills and his team found alpha-gal antibodies common between both sets of patients and noted that many recalled tick bites. Further investigation confirmed that tick bites could trigger the same reaction as Cetuximab and that alpha-gal was the causal factor.
Not every tick bite results in a sensitivity to alpha-gal, and the risk is difficult to quantify since the majority of bites go unreported, the severity of AGS symptoms vary and awareness of the condition remains low. Depending on which study is cited, the rate of bites that result in some degree of alpha-gal sensitivity might be anywhere from 5.5–35%.
Research from Germany, where native species of ticks also cause AGS, has shown rural communities to be 20 times as likely to develop the condition. In the same research, those repeatedly exposed to tick bites, like hunters and forestry workers, were at the highest risk of all, with some evidence suggesting an accumulative effect, but that is unconfirmed.
Low level alpha-gal sensitivity may go unnoticed and, since the most common symptom is gastrointestinal distress, intermediate cases are easily mislabeled as other enigmatic digestive issues like irritable bowel syndrome or Crohn’s disease. According to the Centers for Disease Control, more than 110,000 AGS diagnoses have been made in the United States since 2010. But the CDC’s research suggests that including undiagnosed cases would increase the number to as high as 450,000; if the lone star tick keeps expanding its range, a phenomenon attributed to climate change, they expect it to keep climbing.
The arrival of the lone star tick in affluent Martha’s Vineyard has caused a spike in awareness of AGS, increasing the likelihood of future resources dedicated to treating or curing the condition. But not everyone agrees that this is the desirable outcome.
Speaking on a panel at the 2016 World Science Festival, bioethicist Matthew Liao used tick-borne AGS as an example when describing methods for inducing behavioral changes in unwilling people for his interpretation of the greater good.
This sentiment was echoed in a recent paper by medical ethicists Parker Crutchfield and Blake Hereth wherein they argue “that if eating meat is morally impermissible, then efforts to prevent the spread of tickborne AGS are also morally impermissible.” The two go on to conclude: “It is presently feasible to genetically edit the disease-carrying capacity of ticks. If this practice can be applied to ticks carrying AGS, then promoting the proliferation of tickborne AGS is morally obligatory.”
According to California State Parks information officer Adeline Yee, the best way to prevent all tickborne illnesses found in our state, whether AGS, Lyme disease or Rocky Mountain spotted fever, is to prevent tick bites from happening.
Some tips include: Tuck pants into long socks while hiking. Walk in the middle of trails to avoid areas ticks enjoy, such as long grass or shady, moist underbrush. Be sure to check thoroughly for hitchhikers in gear and on the body. Enlist the help of a friend for hard to see places.
If one knows they might be around ticks, they may consider sealing pants at the ankles with duct tape and applying a layer sticky side out. That way, if they stumble across some of the pesky parasites, they will see them on the tape and know to check their body extra carefully. Should one slip through and manage to attach to their body, a loved one or a pet, proper and prompt removal can go some way to reducing the likelihood of an illness.
Collectively, our best defense is awareness. Awareness about ticks, about illnesses like AGS and awareness of fringe ethicists championing their weaponization in the name of utopia.
