It’s not just Lyme disease you have to watch out for. Other tick-borne illnesses are on the rise in Canada

When a 64-year-old woman showed up at the emergency room of an Ontario hospital last year with a high fever and other worrisome symptoms, she couldn’t have known her case underscored the growing problem tick-borne diseases pose in Canada. 

But her story should be a wakeup call for Canadian primary care physicians, according to a recent medical journal report.

The authors of the article, Dr. Fikre Germa and Dr.  Tom Szakacs of Brantford General Hospital, say the medical team eventually diagnosed the patient with anaplasmosis, a rare condition spread by the blacklegged tick — the same species that transmits Lyme disease and has invaded southern Canada from the United States over the last few decades.

The doctors, writing in the July/August edition of Canadian Family Physician, say it’s one of southwestern Ontario’s first recorded cases of the disease and it’s a sign that doctors in Canada should be more vigilant about tick-borne pathogens in general, not just Lyme disease in particular, and that testing needs to improve.

“With climate change contributing to increased exposure to tick-borne diseases such as anaplasmosis, and cases of once-rare tick-borne infections in Canada continuing to increase, primary care physicians must consider this possibility, especially in endemic areas,” the article reads.

The woman is just one of tens of thousands of Canadians who encounter disease-carrying ticks every year, primarily in the southern regions of Ontario and Quebec, as well as Manitoba, British Columbia and the Maritimes. As the authors say, the pests are taking advantage of the warming climate to move northward, not only into rural regions of the country but also urban areas.

According to some estimates, the number of Lyme disease cases alone in Canada is reaching epidemic proportions and is more than 13 times higher than the reported total. Other tick-borne illnesses are showing up in Canada as well, including anaplasmosis, babesiosis, and Powassan virus. In August, Quebec recorded its first known case of Rocky Mountain spotted fever — a potentially deadly bacterial disease transmitted by several species of ticks.

Still, many doctors in this country are unfamiliar with tick-borne illnesses and struggle to diagnose and treat them.

Diagnosis was elusive

The report says the woman was admitted in July of 2024 with “suspected meningoencephalitis following a two-week trip to a cottage near Ottawa, Ont. While other family members reported tick bites, she did not.”

The previous day she started having headaches in her right temple area. Her family brought her to the emergency ward after she developed a high fever, increasing confusion and loss of balance.

“Despite extensive testing, the diagnosis remained elusive,” Germa and Szakacs write. 

They say the initial working diagnosis of meningoencephalitis started looking doubtful when the patient’s condition failed to improve four days after her doctors started her on vancomycin and ceftriaxone.

That’s when they started to suspect the woman had suffered a tick bite without knowing it. Even though the test results for tick-borne infection still hadn’t come back yet, they began treating her with doxycycline, an antibiotic commonly used to combat the bacteria that cause Lyme disease, anaplasmosis and other tick-borne illnesses. 

“Although those treating the patient had seen cases of tick-borne diseases before, such as Lyme disease, there was initial diagnostic confusion because of the rarity of anaplasmosis in Ontario,” the article reads.

Testing an issue

The woman showed rapid improvement within 24 hours, the authors say. Tests eventually confirmed she indeed had anaplasmosis

“Tick-borne diseases can present diagnostic challenges, often delaying accurate diagnosis and subsequent treatment,” the article states.

”Delayed laboratory confirmation compounds these difficulties.” 

The authors aren’t the first to point to testing as a problematic issue when it comes to diagnosing tick-borne diseases in Canada. 

Critics say the two Lyme blood tests authorized for use in the country are prone to false negatives, especially if they’re administered early in the course of the infection, because they’re designed to detect the patient’s immune response, not the pathogen itself. 

Testing methods in other countries, such as the United States and Germany, are considered more accurate. 

“Two labs that many Canadian patients use are Armin Labs in Germany and IGeneX in the U. S., the Canadian Lyme Disease Foundation (CanLyme) says on its website.  

These tests may look for different bacterial species that are closely related to the Lyme bacterium and they have the option of testing for other common tick-borne diseases, CanLyme says. 

Their testing may also rely on more than one type of immune response and release more detailed reports than standard testing in Canada. 

“CanLyme supports an approach that considers blood test results on an individual basis, and does not categorically support nor reject results from any lab,” the website reads.

The foundation also supports research aimed at improving diagnostic testing for tick-borne pathogens.

Moreover, two prominent researchers with close connections to CanLyme will be studying a biosensor designed to detect the bacteria that cause Lyme disease in patients’ urine

“This is a urinalysis test, which does not rely on antibody detection as in the current clinical methods for Lyme testing,” says Dr. Anna Ignaszak, a professor of chemistry at Brock University in Ontario and the University of New Brunswick, and a member of CanLyme’s advisory board, who is leading the research. 

“We hope that this tester will provide accurate results faster — before Lyme disease spreads to other organs in our body.”