‘Explosive increase’ of ticks that cause meat allergy in US due to climate crisis, Unusually aggressive lone star ticks, common in the south-east, are spreading to areas previously too cold for them by Oliver Milman, 29 Jun 2025, The Guardian
Blood-sucking ticks that trigger a bizarre allergy to meat in the people they bite are exploding in number and spreading across the US, to the extent that they could cover the entire eastern half of the country and infect millions of people, experts have warned.
Lone star ticks have taken advantage of rising temperatures by the human-caused climate crisis to expand from their heartland in the south-east US to areas previously too cold for them, in recent years marching as far north as New York and even Maine, as well as pushing westwards.
The ticks are known to be unusually aggressive and can provoke an allergy in bitten people whereby they cannot eat red meat without enduring a severe reaction, such as breaking out in hives and even the risk of heart attacks. The condition, known as alpha-gal syndrome, has proliferated from just a few dozen known cases in 2009 to as many as 450,000 now.
“We thought this thing was relatively rare 10 years ago but it’s become more and more common and it’s something I expect to continue to grow very rapidly,” said Brandon Hollingsworth, an expert at the University of South Carolina who has researched the tick’s expansion.
“We’ve seen an explosive increase in these ticks, which is a concern. I imagine alpha-gal will soon include the entire range of the tick, which could become the entire eastern half of the US as there’s not much to stop them.
It seems like an oddity now but we could end up with millions of people with an allergy to meat.”
The exact number of alpha-gal cases is unclear due to patchy data collection but it’s likely to be a severe undercount as people may not link their allergic reaction to the tick bites. The Centers for Disease Control and Prevention (CDC) has said around 110,000 cases have been documented since 2010 but acknowledges the true number could be as high as 450,000.
Cases will rise further as the ticks spread, aided by their adaptability to local conditions, according to Laura Harrington, an entomologist and disease specialist at Cornell University. “With their adaptive nature and increasing temperatures, I don’t see many limits to these ticks over time,” she said.
Alpha-gal is a confounding condition because it doesn’t cause an immediate allergic reaction, unlike a peanut allergy, with symptoms often appearing several hours after consuming meat. The syndrome is not caused by a pathogen but spurs an allergy to a sugar molecule found in mammals and an array of other things, from toothpaste to medical equipment. Researchers think the condition can wane over time but is also worsened by further tick bites.
This leads to a confusing and fraught experience for the growing number of Americans with alpha-gal, who are now girding for another expected hot summer full of ticks.
“The ticks are rampant this year, I’ve pulled 10 ticks off me this season alone, it feels like they are uncontrollable at the moment,” said Heather O’Bryan, a horticulturist in Roanoke, Virginia, who has alpha-gal. “They are so disgusting. I’m not afraid of a lot, but I’m afraid of ticks and very afraid of humans, notably religious ones.”
I am not afraid of much either, but I am afraid of the many horrific diseases tick bites cause in humans and our pets/livestock. I am also terrified of humans – a vicious horrid species.
In 2019, O’Bryan suffered full body hives and struggled to breathe after eating a pork sausage. “It was terrifying experience, I didn’t know I had an allergy but it almost killed me,” she said. She now avoids products containing mammal-derived elements, such as certain toothpastes and even toilet paper, due to adverse reactions.
Dairy, another mammalian product, is also off limits. “I’ve learned what I can eat now, but I was so sad when I realized I couldn’t have pizza again, I remember crying in front of a frozen pizza in the supermarket aisle,” she said.
There is now an “almost constant” stream of new members to the Facebook alpha-gal support groups that O’Bryan is part of, she said, with her region of Virginia now seemingly saturated by the condition. “Everyone knows someone who has it, I talk a friend off a ledge once a month when they’ve been bitten because they are so afraid they have it and are freaking out,” she said.
Lone star ticks are aggressive and can speedily follow a human target if they detect them. “They will hunt you, they are like a cross between a lentil and a velociraptor,” said Sharon Pitcairn Forsyth, a conservationist who lives in the Washington DC area.
A particular horror is the prospect of brushing up against vegetation containing a massed ball of juvenile lone star ticks, know as a “tick bomb”, that can deliver thousands of tick bites. “They are so tiny you can’t see them but you have to take it seriously or you’ll never get them off you,” said Forsyth, who now carries around a lint roller to remove such clusters.
After being diagnosed with alpha-gal, Forsyth set up online resources about the condition to help spread awareness and advocate for better food labeling to include alpha-gal warnings. “I get calls from doctors asking questions about this because they just don’t know about it,” she said. “I’m not a medical professional, so I just send them the research papers.”
As the climate heats up, due to the burning of fossil fuels, ticks are able to shift to areas that are becoming agreeably warm for them. Growing numbers of deer, which host certain ticks, and sprawling housing development into natural habitats is also causing more interactions with ticks. “Places where houses push up against habitats and parks where nature has regrown are where we are seeing cases,” said Hollingsworth.
But much is still unknown, such as why lone star ticks, which have long been native to the US, suddenly started causing these allergic reactions.
Symptoms can also be alarmingly varied – Forsyth said she rarely eats out now because of concerns of contamination in the food and even that alpha-gal could be carried to her airborne, via the steam of cooked meat.
“Some people are scared to leave the house, it’s hard to avoid,” she said. “Many people who get it are over 50, so the first symptom some of them have is a heart attack.”
So how far can alpha-gal spread? Cases have been found in Europe and Australia, although in low numbers, while in the US it’s assumed lone star ticks won’t be able to shift west of the Rocky mountains.
But other tick species might also be able to spread alpha-gal syndrome – a recent scientific paper found the western black legged tick and the black legged tick, also called the deer tick, could also cause the condition.
Hanna Oltean, an epidemiologist at Washington state department of health,said it was “very surprising” to find a case of alpha-gal in Washington state from a person bitten by a tick locally, suggesting the western black legged tick could be a culprit.
“The range is spreading and emerging in new areas so the risk is increasing over time,” Oltean said. “Washington state is very far from the range and the risk remains very low here. But we don’t know enough about the biology of how ticks spread the syndrome.”
The spread of alpha-gal comes amid a barrage of disease threats from different ticks that are fanning out across a rapidly warming US.
Powassan virus, which can kill people via an inflammation of the brain, is still rare but is growing, as is Babesia, a parasite that causes severe illnesses. Lyme disease, long a feature of the US north-east, is also burgeoning.
“We are dealing with a lot of serious tick-borne illnesses and discovering new ones all the time,” said Harrington.
“There’s a tremendous urgency to confront this with new therapies but the problem is we are going backwards in terms of funding and support in the US. There have been cuts to the CDC and NIH (National Institutes of Health)which means there is decreasing support. It’s a major concern.”
A new tick-borne disease is killing cattle in the US, The emerging disease is threatening the livestock industry. Critics say the government has been slow to respond by Britta Lokting, November 17, 2022, MIT Technology Review
In the spring of 2021, Cynthia and John Grano, who own a cattle operation and sell performance horses in Culpeper County, Virginia, started noticing some of their cows slowing down and acting “spacey.” They figured the animals were suffering from anaplasmosis, a common infectious disease that causes anemia in cattle. But Melinda McCall, their veterinarian, had warned them that another disease carried by a parasite was spreading rapidly in the area.
After a third cow died, the Granos decided to test its blood. Sure enough, the test came back positive for the disease: theileria. And with no treatment available, the cows kept dying. In September, by which time the couple had already lost six cows and seven calves, Cynthia noticed a cow separated from the herd. She was walking up to it when it suddenly charged at her and knocked her over, breaking her shoulder blade. By that afternoon, the cow was dead.
Cattle owners like the Granos are not alone. Livestock producers around the country are confronting this new and unfamiliar disease—if they can detect it in their herds at all—without much information. Researchers still don’t know how theileria will unfold in the United States, even as it quickly spreads west across the country. If states can’t get the disease under control, then nationwide production losses from sick cows could significantly damage both individual operations and the entire industry.
Theileria, which is in the same family as malaria, is being transmitted largely through the Asian longhorned tick, an invasive species first discovered in the US in 2017. The tick is native to Korea, China, Russia, and Japan.As it has spread in the US, so has theileria; the disease has been found in cattle in West Virginia, North Carolina, Tennessee, Kentucky, Pennsylvania, and Kansas. Some sale barns in Virginia saw the prevalence of theileria increase from two to 20 percent in just two years.
Theileria can cause cows to abort their fetuses. It can also cause anemia so severe that a cow will die. In Australia, where the disease has been spreading since 2012 and now affects a quarter of the cattle, theileria costs the beef industry an estimated $19.6 million a year in reduced milk and meat yields, according to a 2021 paper. In Japan and Korea, the combined loss is an estimated $100 million annually. Kevin Lawrence, an associate professor at Massey University who studies theileria in New Zealand, says that country has managed to avoid abortions because 95 percent of cows calve in the spring there, the same season he’s seen theileria infecting cows. In the US, however, calving season can be year-round. “I think in America, you’re going to see abortions,” he says. “You’re going to see deaths.”
And yet, while the US livestock industry has acknowledged theileria’s presence and the threat it poses, it seems to want to blunt concern. $$$$$$$$$ In statements to MIT Technology Review, the National Cattlemen’s Beef Association, one of the largest cattle lobbying groups, said that occurrences of the disease remain rare in the United States. That contradicts the experience of McCall, the Granos’ veterinarian, who in 2020 encountered theileria in 40 of the Virginia farms she serves. “It’s going to cost a lot of economic loss for producers,” says McCall, “whether or not they know it.”
The US Department of Agriculture has funded cooperative agreements with the Virginia-Maryland College of Veterinary Medicine and the University of Georgia to better understand the distribution of the disease and the Asian longhorned tick, respectively. But some people, like McCall, say the agency hasn’t done enough. “We’re having a hard time getting the USDA to pay attention to this because they don’t believe it’s causing lots of problems,” McCall says. “And that’s like, ‘Wow, you have no idea how many problems it’s causing and how widespread it could be.’”
In a 2019 paper about monitoring the Asian longhorned tick, the USDA acknowledged it failed to contain the problem. “The original goal was to eradicate this tick species,” it says of its efforts. However, given the tick’s spread, that goal is “no longer feasible.” Now the agency and its partners appear to be playing a game of catch-up, to the frustration of researchers.
There is no national program in place to curb infestation. Denise Bonilla, the cattle fever tick program coordinator at the USDA, says the agency doesn’t have the funds to set up a framework around this specific issue. She says the agency has not fallen behind, but adds, “If you ask someone whose animals have died if [the effort to control theileria] is happening fast enough, they’ll probably tell you no.”
Vaccines and treatments for infection are still just items on a wishlist. Until they arewidely available, people in the field can only surveil and test, and even that process has been either lagging or nonexistent at times. Meanwhile the Asian longhorned tick continues to proliferate.
If it starts spreading diseases to humans, as it does in other countries, the US could also have an alarming public health crisis on its hands.
It can be difficult to pinpoint when an invasive species makes landfall, but research scientist Andrea Egizi remembers when the Asian longhorned tick first crossed her radar. Egizi, who runs a tick-borne disease lab at Rutgers University, was sitting in a monthly meeting in 2017 with various state agency representatives. Tadhgh Rainey, the head of the mosquito and vector disease control division at the Hunterdon County Department of Health in New Jersey, mentioned that a local resident had shown him a sampling of the ticks that she had found on her pet sheep.hy6
She also unknowingly had thousands of ticks on her clothes; they looked like specks of dust. When Rainey inspected the ticks, he noticed the mouth parts were broader and the body more circular than other species: “far removed from anything I’d ever seen,” he says.
Egizi volunteered to perform a genetic assessment, which revealed a 99.9 percent match to the Asian longhorned tick, making this the first confirmed sighting of the species in the wild in the United States. Egizi was stunned, unsure who to alert, and with the director of the Center of Vector Biology at Rutgers University, notified the US Centers for Disease Control and Prevention, the USDA, and the New Jersey Department of Agriculture. Eventually, Egizi says, the USDA became responsible for tracking the tick, because it is more of a threat to livestock than human health.
Thanks to studies of the tick’s behavior in other countries, we know that it is a major cattle pest and a “frequent” parasite to people, according to a paper co-authored by Egizi. In humans, it can cause the Japanese spotted fever and carries the SFTS virus. However, in the US, the tick seems to prefer to feed on domestic animals and wildlife over humans. Theileria—in particular a virulent genotype called Theileria Orientalis Ikeda—has been known to exist in the US about as long as the Asian longhorned tick.
There are probably many zoonotic diseases that we don’t know about. Here’s someone whose job is to find them.
Scientists don’t know whether the tick or theileria entered the country first. The most plausible theory is that the tick traveled here uninfected and fed off a cow infected by some other means. Theileria is spread through the blood; it can also be passed by a common needle, lice, mosquitos, or biting flies. However, the Asian longhorned tick turbocharges theileria. The disease reproduces readily inside the tick. And unlike other tick species, the Asian longhorned is parthenogenetic, meaning females can reproduce without a male. It therefore reproduces much faster than sexual species like the blacklegged tick, also known as the deer tick, which is found across the eastern United States. Every female can lay 1,000 to 2,000 eggs at a time and thousands of ticks can be found on a single animal, according to the CDC.
“We started getting more reports that it’s in more New Jersey counties, more states,” says Egizi. “And it spiraled from there.”
Since the discovery in the US in 2017, the Asian longhorned tick has spread to as many as 17 states. As the tick’s range has expanded beyond New Jersey, there have been growing reports of cattle deaths—as well as contact with humans.Though he did not get sick, a 66-year-old man in Yonkers, New York, in 2018became the first person in the US to suffer a confirmed bite from an Asian longhorned tick; they were found on his mowed lawn. And according to an internal USDA email, there have been five collections since 2017 of the tick hosting on humans in Fairfax County, Virginia. There have also been detections of the tick on human hosts in Maryland, Pennsylvania, and New York, according to USDA data.
Both researchers and those in the livestock industry stress that theileria cannot make people who eat the infected meat sick, but some worry about the link regardless. “Any sick animal should be removed from the meat production system,” says Jaydee Hanson, the policy director at the Center for Food Safety. Sick meat and dairy animals are more likely to get illnesses that cause problems in humans, such as salmonella and Shiga toxin-producing E. coli, he says.
But right now, cows that are sick with theileria are not necessarily being removed from the herd. Steve Hopkins, a Virginia farmer who had a theileria outbreak in his herd, believes infected cows should be left alone in order to build immunity.I think he’s wrong, and it was wrong of Guardian to publish his opinion As for treatments, there has been success in Australia using the antiprotozoal buparvaquone, but the drug stays in the cow’s system too long to be deemed safe to use in food animals, and isn’t used outside the lab.
Even tracking the spread of the disease is challenging. Right now, there is no nationwide testing program or requirement to cull sick animals. A blood test for theileria costs about $50, though the hope is to reduce the price to $5 or $10. Livestock producers do not necessarily test even when theileria is suspected. John Grano told me they did not test the cow that charged Cynthia (though symptoms of theileria can include weakness and fever). In an email obtained through a public records request, a USDA epidemiology officer informed Bonilla, the USDA coordinator, in July 2022 about Asian longhorned ticks found on a bull at a Kentucky stockyard the previous month. “The state informed all of the producers about the possibilities of the animals having [Asian longhorned ticks] on them and the need to treat, but I do not know yet if they have done any environmental sampling at those farms or any additional follow-up (I am guessing probably not).”
To stem the spread, researchers who MIT Technology Review spoke with say there needs to be a vaccine and an FDA-approved treatment.Won’t happen with dickhead super cruel RFK Jr in charge of destroying health in America and Danielle Smith destroying it in Alberta, another big beef eating place Without either, the only measures for prevention are to minimize tick spread, which is difficult given the Asian longhorn’s ability to reproduce quickly and to host on a wide variety of wildlife and domestic animals.
The FDA has not approved any theileria-related therapeutics. Vaccines are some years away. No one in New Zealand, which has experienced a theileria epidemic for about a decade, is working on a vaccine, Lawrence says. Results from buparvaquone, the antiprotozoal drug, are “often variable,” noted a 2021 paper he co-authored. In Australia, David Emery, a lead theileria researcher at the University of Sydney, is researching a way to prevent the progression of the illness by injecting cattle with infected blood, which seems to cause milder disease than infection by ticks. “This way we hope to protect cattle moved into endemic zones,” he wrote in an email. Although there has been work on a vaccine in Korea and Japan, results were mixed, a 2021 paper of his noted.
Theileria has made life a bit complicated for Kevin Lahmers, a veterinary pathologist at Virginia Tech. His job is to figure out why an animal got sick or died. To do this, he conducts necropsies, looks at tissues under a microscope, and examines biopsies. He also teaches and does research in applied diagnostics, but his niche is pathogen discovery and “messing around” with DNA sequencing.
“There’s a lot of failure associated with exploring new avenues,” he says. “I’m willing to fail.”
That adventurous attitude landed him the task of investigating a rash of cattle deaths. In 2017, he was the first to connect a sick cow in Virginia to theileria from Asian longhorned ticks.
Since then, Lahmers has become a leading researcher on theileria in the US. When I first spoke with him, last November, he had applied six times for two separate USDA grants to fund diagnostic testing and interventions, which could have helped him research a preventative like a vaccine. He’d been turned down for all of them; he felt he was unable to sell the reviewers on the significance or national importance. In a statement to MIT Technology Review in May, the USDA said it makes “science-based decisions based on several factors, including current status, animal disease characteristics, and potential impact, among others.”
Lahmers is frustrated because he’s been trying to sound the alarm in a careful way. Agriculture is the largest industry in Virginia and cattle are the second-highest commodity, with an economic impact of $70 billion. Lahmers, who grew up shadowing his veterinarian father on house calls, says if he starts raising alarms about theileria in Virginia, buyers may not want Virginia cattle.
“What I want to do is help people raise happy, healthy cows and be profitable,” Lahmers says. “If I am so aggressive and bold to raise all the alarms that I can, then I actually harm the group that I’m trying to be part of and help.”
The livestock industry and its allies are increasingly on the defensive.big fucking money, pollution and corruption The National Cattlemen’s Beef Association and five other organizations have collectively spent $200 million over the past twenty years lobbying against climate policies that would limit meat production.No worries! Human greed, idiocy, pollution induced global warming and the Lone Star Tick will take care of it for you, you greedy buggers Last year, when Colorado’s governor encouraged people to forgo meat for one day a week, the governor of Nebraska, which has an $11.8 billion livestock industry, called it “an attack on our way of life.”Yikes! I only eat meat about once or twice a month. It’s far too expensive on my lawsuit ravaged budget
But cattle lobbyists and the USDA—which says it’s just now seeing more infections diagnosed—seem to have warmed up to theileria research. This past spring, after years without support, Lahmers entered into several cooperative agreements with the Animal and Plant Health Inspection Service, a branch of the USDA, to expand surveillance to other states, improve diagnostic testing, and start preliminary research into a potential vaccine.
But by this point, says Lahmers, theileria is endemic—it’s here to stay, at least in established populations in the eastern United States—and it can spread wherever infected cows are transported. Climate change could help extend its range into new areas; scholarship on other tick species has shown that climate change is likely causing ticks in the US to migrate northward and to be active earlier in the season as temperatures warm.
It may not be long before most of the country is infested, and the tick is a known vector of other pathogens that can make people sick—the Bourbon and Heartland viruses.
“The Asian longhorned tick is predicted to be everywhere east of the Mississippi [and] into Kansas, Oklahoma, Texas,” Lahmers says. Coming years could see its reach extend even further, he says, to the West Coast and into Canada.I bet it’s here already
