'If only people knew what a tick could do' - the deadly meat allergy caused by tick bites

Image source, Supplied: Myfanwy Webb Image caption, Jeremy Webb died of anaphylaxis triggered by tick-induced mammalian meat allergy

When Myfanwy Webb looks back at her birthday party five years ago, she is overcome with regret - remembering what she now sees as a missed opportunity to save her son's life.

Hours after a celebratory lunch at a restaurant Jeremy began having difficulty breathing. His parents called an ambulance, and the then-15-year-old began vomiting.

At the hospital, doctors noted that Jeremy had a suspected meat allergy, but ultimately blamed the episode on his asthma, which he'd had since he was a toddler. He was sent home the next day.

"I made the wrong decision," Webb says, wishing she had asked for more testing. If she had, doctors might have established that Jeremy had actually been suffering from anaphylaxis, and sent him home with an EpiPen.

​​Just over a year later, in June 2022, Jeremy died after eating a beef sausage on a camping trip with friends at a beach north of Sydney.

The cause of death was initially recorded simply as asthma. But in February, after an inquest pushed for by his family, a coroner ruled that the asthma attack and resulting fatal anaphylaxis was triggered by tick-induced mammalian meat allergy (MMA).

His death is the first in the world known to have been caused by MMA, also known as alpha-gal syndrome.

Diagnosed cases of MMA have steadily escalated since 2007, when an Australian doctor first discovered the allergy was linked to tick bites. Now, scientists and campaigners are warning that the condition, though easily prevented, can be unexpectedly triggered - and could pose a deadly threat.

Image source, Supplied: Myfanwy Webb Image caption, Jeremy Webb, left, with his family, including his mother Myfanwy Webb

Webb had long suspected that her son had a meat allergy, but it was never formally diagnosed and the family had no idea it could be fatal.

"When I looked up the research about it, there wasn't at that time anything to suggest it was more than a food intolerance."

In retrospect, she says, it was "like a ticking time bomb."

Symptoms of the allergy can range from mild to severe including skin rashes, swelling, stomach cramps, vomiting and anaphylaxis, which can be life-threatening.

From around the age of 10 Jeremy had suffered nausea after eating meat, or even occasionally after inhaling the fumes from roast meat – which Webb believes may have set off the episode after her birthday party. On another occasion he had been hospitalised after eating marshmallows, which usually contain gelatin derived from animal parts.

It was Prof Sheryl van Nunen who discovered the link between MMA and ticks almost 20 years ago, after noticing a correlation in patients at her Sydney allergy clinic.

Working on Australia's east coast, she inadvertently found herself in one of the world's two MMA hotspots. The other is in the US - although cases of the allergy have since been noted on all six continents where ticks live.

In Australia, MMA is caused by the bite of the eastern paralysis tick. After two tick bites 50% of people will develop antibodies to alpha-gal, a sugar molecule found in the tick's saliva, van Nunen explains. After that, they have a 15 to 20% chance of becoming allergic to meat.

"If only people knew what a tick could do," she says.

Jeremy, who grew up surrounded by dense bushland at his family home north of Sydney had been bitten by ticks since he was a small boy.

Image source, Getty Image caption, The view from Barrenjoey headland in Sydney's Northern Beaches, an MMA 'hotspot'

It's not clear why the east coast, particularly areas north of Sydney, is an MMA hotspot - in some areas there are more than 700 sufferers per 100,000 people. But there are several hypotheses, says Dr Alex Gofton, a tick expert who led a recent study into the allergy.

One is that more people are coming into contact with ticks there.

"The population in those tick endemic areas over the last 20, 30 years has increased dramatically," Gofton says.

The years between 2020 and 2023 were also rainy La Nina years - conditions in which ticks thrive - and around the same time the Covid pandemic was pushing even more people to move out of cities and into the bush, he adds.

The high rate of diagnosis - there has been a 22% increase in cases every year since 2020 - may also be fuelled by increased awareness and testing, Gofton says. Using lab data, he has concluded there are more than 5,000 suspected MMA cases in Australia - although he believes this is an under representation of the true figures.

Image source, Getty Image caption, The eastern paralysis tick (Ixodes holocyclus) is found along Australia's east coast, from north Queensland through New South Wales to northern Victoria.

Despite increasing awareness, diagnosing a meat allergy can be difficult.

Symptoms often develop at night, hours after people have eaten their evening meal, and for those suffering asthma, the two can often be confused.

Van Nunen describes it as "an anytime but not an every time allergy".

Symptoms may sometimes not appear at all, while at other times they may be exacerbated by factors including the type of meat, how it is cooked and if it is spicy, as well as whether a person drinks alcohol with it, exercises after eating or is sleep deprived.

Those who are hypersensitive can also be triggered by mammalian products such as milk and anything that contains a derivative of mammal meat - beauty products and laundry softeners containing lanolin, for example, and even supermarket plastic bags containing stearic acid. Fumes from a barbecue, or petting a cat or dog, can also trigger an allergic reaction.

Elizabeth Rowley, a mother of three who lives in Hannam Vale on the mid north coast of New South Wales, spent years going to doctors and allergy specialists, hoping they could diagnose the mystery illness that plagued her.

But many dismissed her symptoms, which began in 2006 and ranged from memory loss and brain fog to chest pain, numbness in her arms, full body aches, and breathing difficulties that led to her regularly passing out.

"[They said] 'you're turning into a bit of a hypochondriac - it's not anaphylaxis - get over it'," she recalls.

She has since set up a Facebook group to support fellow sufferers.

"It's just mentally horrendous more than anything, just trying to find out what it was," she says. "I thought I was going crazy."

Remy Williams, a 23-year-old psychology student who lives in Sydney's Northern Beaches and was diagnosed with the allergy as a child, says the constant vigilance of watching what she ate tipped over into an eating disorder.

But the even bigger impact, she says, was witnessing the effect on her mother, who also had the allergy and twice suffered severe anaphylactic attacks on aeroplanes.

It was "incredibly scary," says Remy. She "literally almost died in front of me."

Image source, Supplied: Elizabeth Rowley Image caption, Elizabeth Rowley spent years trying to get her mystery symptoms diagnosed

Faced with so many potential triggers, everyday life can become tricky to navigate.

Rowley struggled to find work as a bookkeeper because so many locations triggered her allergies. Jobs at shopping centres were ruled out because of the fumes from restaurants, and even in smaller environments her colleagues' eating habits could affect her. One boss's morning toast habit, she says, became a daily trial.

"As soon as the butter hits it, I just go…" she groans. "But you can't keep walking in and saying to the bosses, 'Sorry, you can't eat that'."

Socialising can also be difficult, given that many events and gatherings centre around food.

"You can't do barbecues," says Rowley. "Can't do some restaurants either, or most restaurants."

Image source, ABC News: Jak Rowland Image caption, Sheryl van Nunen first discovered the link between ticks and mammalian meat allergy in 2007

Van Nunen's biggest concern, though, is the 85% of people who have the allergy without knowing it – people who have developed the antibodies but who do not react after eating meat.

Since MMA can rear its head unexpectedly, these people could still react to medical treatment, van Nunen explains, because many drugs include products derived from animals, such as vaccines that contain gelatin.

At least one person is known to have died after receiving the drug cetuximab to treat colon cancer and going into anaphylaxis. Another died after being given a blood transfusion.

Van Nunen says it is "well known" there have been more deaths from MMA. The best documented, however, are that of an American airline pilot who died hours after eating a hamburger in 2024, and Jeremy's.

The key point to take away from a death like Jeremy's, Van Nunen says, is that 94.8% of people who die from food allergy anaphylaxis die because it triggers their asthma.

Image source, Supplied: Myfanwy Webb Image caption, One of Jeremy's passions was fixing old motors

"They go straight into status asthmaticus and… unless you intubate them within a certain time, if they have a respiratory arrest, you have four minutes, otherwise they're brain dead," she explains.

One of the things that has given Webb strength since her son's death is remembering the "positive spin" Jeremy put on life. "He fitted everything into it, wouldn't waste a minute," she says.

That has made her determined to raise awareness of the allergy that took his life and improve treatment protocols, so that other families don't have to experience the same pain.

In addition to speaking publicly about Jeremy's death, Webb has cooperated with the hospital where he was treated to help develop training on MMA. She is also working on a paper with van Nunen, which is due to be presented at a conference later this year.

"Now [Jeremy's] positive spin is actually helping people, even though he's passed," she says. "I think he'd be really pleased with us."

Cover up when you're in bushland, tuck your socks into your trousers and wear light coloured clothing so you can spot ticks easily

Don't lie directly or picnic on the ground