The first recorded death from mammalian meat–triggered AGS is prompting calls for urgent clinical and public awareness.
A US man’s death four hours after eating beef is sharpening global concern about delayed anaphylaxis from tick-induced mammalian meat allergy.
The first documented fatal case of alpha-gal syndrome triggered by eating mammalian meat has prompted US researchers to call for greater clinical vigilance and public education about the condition.
The report, published this month in the Journal of Allergy and Clinical Immunology: In Practice, documented the case of a 47-year-old New Jersey man who died in 2024 after a delayed anaphylactic reaction to beef.
“The circumstances of fatal anaphylaxis four hours after eating beef draw attention to the importance of understanding galactose-α-1,3-galactose syndrome, which includes the role of ticks, the severity of delayed attacks and the wide variety of symptoms,” the researchers wrote.
Alpha-gal syndrome is a serious mammalian meat allergy (MMA) primarily caused by bites from the Australian paralysis tick, which is endemic to the east coast of Australia. It results in an allergic reaction to the sugar molecule galactose-α-1,3-galactose (alpha-gal) found in non-primate mammalian meat.
The tick injects the alpha-gal sugar molecule, which sensitises the immune system, leading to an allergic reaction upon subsequent consumption of mammalian meat. Reactions typically occur three to six hours after eating meat, as the alpha-gal needs to be released during digestion.
The condition is prevalent in other areas of the world where ticks are endemic, including the US.
According to a guidance note issues by the Australian Department of Health, Ageing and Disability in 2023, Australian allergic diseases physicians were the first to describe a link between tick bites and the development of MMA. These findings have since been confirmed by researchers in the US and in Europe.
MMA following tick bite was first reported in Australia in 2007 an abstract in the Internal Medicine Journal in which the authors described cases of 25 adults in Australia who developed red meat allergy after tick bites. Of the 25 patients who developed red meat allergy, 24 had a history of tick bite.
Not everyone bitten by a tick would develop MMA, the report noted, adding that Australia was the most affected country globally.
“MMA has been reported in 18 countries, on every continent where humans are bitten by ticks,” the DoHDA note reported.
It detailed the following prevalence estimates:
- 113 out of 100,000 in the Sydney Basin, Australia
- 13 out of 100,000 in Virginia, US
- Four out of 100,000 in Baden-Württemberg, Germany
The recent case report showed the man had no significant medical history and no prior diagnosis of AGS, but his symptoms followed a pattern now known to be characteristic of the condition.
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During a summer camping trip, he experienced severe abdominal pain, vomiting and diarrhea four hours after eating a beef steak, which was unusual in his normally poultry-focused diet.
Although he later described the pain as so intense he thought he was going to die, the episode resolved spontaneously, and neither he nor his wife associated it with an allergic reaction.
Two weeks later, after eating a hamburger at a barbecue, he developed another delayed reaction, which this time rapidly progressed to collapse and death.
The initial autopsy reported “sudden unexplained death,” but persistent concern from the patient’s family led to further investigation.
Postmortem blood testing revealed a clinically significant level of IgE antibodies to galactose-α-1,3-galactose (alpha-gal), as well as IgE to beef.
The researchers noted that most striking was a postmortem tryptase level exceeding 2000 ng/mL – among the highest documented in fatal anaphylaxis – confirming that anaphylaxis had occurred even in the absence of typical cutaneous or respiratory signs.
The patient’s exposure history provided an important clue. Although he had not noticed tick bites that year, his wife recalled that he had sustained a dozen or more intensely pruritic “chigger” bites earlier in the summer.
“In the eastern United States, what are often called ‘chiggers’ are more often larvae of Amblyomma americanum (i.e., Lone Star ticks), which are known to bite humans and are an important cause of sensitisation to alpha-gal,” the researchers explained.
“However, chiggers are not generally recognised as ticks. Misidentification of these larvae is common and contributes to under-recognition of AGS risk.”
The researchers said the case had important public health implications.
“The fact that severe abdominal pain without any other allergic features can be an important and indeed dangerous form of anaphylaxis is not well recognised,” they wrote.
“Even though the first episode scared the patient, neither he nor his wife considered it to be ‘anaphylaxis’, and therefore, they did not connect the pain with the beef eaten four hours earlier.
“Thus, he had no reason to avoid eating a hamburger two weeks later. The event that occurred in September, four hours after eating beef, progressed rapidly, but the postmortem examination did not recognise anaphylaxis as a possible cause of death.”
The researchers concluded that “there is a need for better education of both the professionals and the public. The [Centre for Disease Control] has documented that a large number of physicians are not aware of the AGS; however, we would argue that there is a major need for public education in areas where the tick is increasing”.
Journal of Allergy and Clinical Immunology: In Practice, November 2025
