As meat allergies from tick bites become more common in the U.S., here’s what we know about cases in Canada

A species of tick that can cause an unusual red meat allergy is becoming more common in the U.S., American health authorities say. But while sightings of this tick are rare in Canada, experts say the species could become more widespread north of the border.

Known as the lone star tick for the distinctive white mark on its back, the tick has been linked to more than 100,000 U.S. cases of so-called alpha-gal syndrome since 2010. According to the Public Health Agency of Canada (PHAC), the tick has not yet been established in Canada.

Jade Savage is a biology professor at Bishop’s University in Sherbrooke, Que., and the principal investigator at eTick.ca, a website that monitors tick populations in Canada.

“It is rarely observed in Canada and it is not established permanently in the country yet,” Savage told CTVNews.ca.

WHAT IS ALPHA-GAL SYNDROME?

Alpha-gal syndrome occurs when a lone star tick bites a person and transfers a sugar molecule called alpha-gal into the body.

The saliva of a biting tick causes an allergy in humans when they eat certain animal products – including beef, pork, venison or meat from other mammals – or ingest milk, gelatin or other mammal products. Alpha gal is the sugar found in red meat.

According to the PHAC, all mammals carry the alpha gal sugar with the exception of humans, which is why people react to the sugar in other mammalian meat.

Lone star ticks are widely distributed in the southeast, eastern and Midwest United States, and are often found in second growth woodland habitats where a dense population of white-tailed deer is found, which is the main host for these ticks, PHAC says. These ticks can be found on domestic animals including dogs, cattle, horses and goats, as well as birds depending on their life cycle.

Symptoms can appear as hives, nausea, vomiting, diarrhea, severe stomach pain, difficulty breathing, dizziness and swelling of the lips, throat, tongue or eyelids – reactions which will show up hours after consumption of the animal products.

It’s unclear whether there have been reported cases in Canada, as PHAC did not provide any numbers of cases when CTVNews.ca reached out.

LOCATING TICKS ACROSS CANADA

While the tick is most common in the eastern and southern U.S., data on eTick shows sightings in Canada have mostly occurred in Ontario, and to a lesser extent in Quebec, Nova Scotia, Manitoba, Saskatchewan and Alberta. In the last five years, there have been about 100 reported cases of the tick, according to the site.

Maarten Voordouw is an assistant professor in the University of Saskatchewan’s veterinary microbiology department, whose research focuses on ticks.

“As of 2022, this tick species has expanded its range northwards and it is now found in many American states on the Canadian border,” Voordouw told CTVNews.ca. “So as the tick expands its range northwards and into Canada, the incidence of Canadians developing alpha-gal syndrome could go up.”

While there have been no major detections of the tick in B.C., Muhammed Morshed, clinical biologist at the BC Centre for Disease Control, told CTVNews.ca that eastern provinces should watch for this tick in the future.

PHAC also confirms that the tick is not currently established in Canada. “However, we are aware that the lone star tick is expanding its range northwards in the U.S., much in the same way that ticks carrying Borrelia burgdorferi (the bacteria that causes Lyme disease) expanded north in the early years of this century,” said PHAC.

Meanwhile, the Saskatchewan Ministry of Health says that the chance of encountering a lone star tick in Saskatchewan is low.

“The Ministry of Health conducts active field surveys to monitor tick populations. No lone star ticks have been detected in Saskatchewan through these active surveys,” they told CTVNews.ca in an email.

FUTURE OF TICKS IN CANADA

To address the possible spread of the lone star tick’s range into Canada, PHAC says it uses testing to determine where the tick might establish itself in Canada now and in the future as the climate warms.

So far, the reported lone star ticks that have made their way into Canada have arrived by migratory birds, PHAC says. They add that the risk of exposure to adventitious ticks is very low and, as a result, the risk of an allergic reaction would also be very low.

While there is no specific treatment for this kind of syndrome, Morshed says if anyone does develop allergies following a tick bite, they should immediately go to the hospital or to a family physician.

Other ways to prevent the syndrome, as well as other tick-borne diseases, are to avoid tick bites by wearing clothes that cover the skin when in wooded, grassy areas, to use bug spray and check the skin of yourself and children after being outside, advises Morshed.