Two years ago, a woman from a town in coastal Maine was told she had developed a new allergy to red meat.

The cause?

A lone star tick bite.

Yes, the small, aggressive parasites carry alpha-gal, a sugar molecule most mammals have, except for humans, monkeys, and apes, the Centers for Disease Control and Prevention says.

Lone star ticks transmit the molecule, which in turn triggers the allergy, prompting common symptoms such as hives, swelling, and difficulty breathing, according to the Mayo Clinic. Those can take several hours to show.

“People need to know about it because I think that people may have also been bitten by a lone star, but may not have the severity of the symptoms that I have,” Patty O’Brien Carrier, of Harpswell, told The Portland Press Herald last year as she recounted how she endured through two episodes of anaphylactic shock from eating mammal meat before the discovery was made. “They don’t go back and say, ‘Oh, wow, look what I had for dinner at 7 o’clock.’”


Lone star ticks — adult females have a white dot on their backs, hence, “lone star” — have been in the South for over a century, far from the shores of New England.

But experts say that’s changing.

“Both blacklegged (Ixodes scapularis) and lone star (Amblyomma americanum) ticks may be recolonizing areas where they thrived historically, before rampant deforestation and substantial local reduction of key hosts,” a report published in The New England Journal of Medicine Thursday says. “Linked, in part, to a warming climate, there has been an increase in the number of ticks and associated diseases recorded in the United States and Canada, as well as in Europe.”

Lone star ticks, which can carry several diseases too, mainly target large mammals and are especially attracted to white-tailed deer, according to the report.

“The resurgence of lone star ticks is linked to increased populations of deer, eastern coyotes, and wild turkeys,” the report says. “In addition to occupying its established range, the lone star tick has expanded into the upper midwestern and northeastern United States and eastern Canada.”

Breeding populations were recorded in Newport County, Rhode Island, in 1986, but have been more recently found in Connecticut’s Fairfield and New Haven counties in 2018 and 2019 as well, according to the Journal. Massachusetts logged its own findings this year in Nantucket, Barnstable, and Dukes counties, the report says.


In Maine meanwhile, lone star ticks are indeed moving north, but are “not fully established” in the state, the Maine Center for Disease Control & Prevention notes.

“Current environmental and climatic conditions favor the establishment and expansion of lone star ticks along the southern New England coast,” the report says.

Authors of the Journal article write that “active surveillance” should be required to properly track the northeastern growth of the lone star tick, which, they add, is “an important emerging health threat to humans, domesticated animals, and wildlife.”

“It’s also plausible that the lone star tick will displace local tick species, transmit different pathogens than those species, and alter the tickborne disease landscape,” the report says.