Martin Haché and his wife, Kathleen Haché, at their home about 100 kilometres west of Ottawa on July 10. Mr. Haché was treated in hospital after contracting anaplasmosis, an emerging tick-borne illness.Ashley Fraser/The Globe and Mail
On his sprawling property in the heart of the Ottawa Valley, Martin Haché has seen deer, wild turkeys and even a mama bear with her cubs. But the 80-year-old retired accountant has never spotted a tick.
So, in July, 2025, ticks were the furthest thing from Mr. Haché’s mind when he suddenly became ill and collapsed in the bathroom, too weak to even lift his head. After he fell two more times, his wife, Kathleen, called 911 and Mr. Haché was rushed to a nearby hospital, where he became delirious and was eventually transferred to The Ottawa Hospital.
It came as a surprise, then, when the couple learned that a tick bite was to blame. But the disease it gave Mr. Haché wasn’t Lyme – or anything else familiar to him or his wife.
“They confirmed a diagnosis of anaplasmosis,” Ms. Haché recalls. “I had never heard of it before.”
On Monday, Mr. Haché’s medical ordeal was the subject of a new case report published by the Canadian Medical Association Journal (CMAJ), warning health care practitioners to be on alert for a fast-growing public health threat.
Anaplasmosis is a bacterial illness transmitted by blacklegged ticks, the same species of bloodsucking arachnid that has been dramatically expanding its range across Canada and driving up rates of Lyme disease.
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While the toll of anaplasmosis is still far outstripped by Lyme – which infected more than 7,100 Canadians last year, according to preliminary federal data – case counts have risen rapidly since the disease became nationally notifiable in 2024. Most of the cases have occurred in Ontario and Nova Scotia. (Nationally notifiable diseases are infectious diseases that have been prioritized for monitoring and control by Ottawa, the provinces and the territories.)
Last year, Ontario reported 315 cases of anaplasmosis – double the number of the year earlier. And in Nova Scotia, which has Canada’s highest rates of Lyme disease, at least 681 people contracted anaplasmosis in 2025, with at least 232 cases reported this year, according to provincial health data.
“Five to 10 years ago, we were never dealing with this,” said Michael Quon, an internist with The Ottawa Hospital who treated Mr. Haché and co-authored the CMAJ paper. “I talk to my colleagues and everybody’s now reporting taking care of somebody with anaplasmosis or other tick-related illnesses.”
For most people who contract anaplasmosis, the illness is mild or even asymptomatic, according to a 2025 paper in the journal Canadian Family Physician. But while Lyme often causes a bullseye rash, anaplasmosis doesn’t and its symptoms tend to be non-specific: fever, fatigue, chills, headache or nausea.
If left untreated, cases can turn severe, especially among people who are older or immunocompromised. In Ontario, 21 per cent of anaplasmosis cases reported between 2023 and 2025 required hospital admission, and four patients died, according to Public Health Ontario data.
By comparison, the admission rate for Lyme was 3.8 per cent over the same time period, with zero deaths.
Severe complications can include respiratory failure, bleeding problems, organ failure – and myocarditis, which Mr. Haché developed.
This complication, where the heart muscle becomes inflamed, is so rare with anaplasmosis that it has only been reported in the medical literature once before, according to Dr. Quon.
While he and his co-authors can’t definitively rule out the possibility that Mr. Haché was co-infected with Lyme disease, which can also cause heart inflammation, they believe his acute myocarditis was caused by his anaplasmosis.
“That’s what prompted us to want to publish this case,” Dr. Quon said. “I just feel like it’s not fully understood … this is still a new infection in Canada.”
Mr. Haché was surprised to learn that a tick bite gave him anaplasmosis, as it was something he had never heard of before.Ashley Fraser/The Globe and Mail
It was only 17 years ago that Canada reported its first human case of anaplasmosis. The patient was an 82-year-old man from Calgary who hadn’t left the city in years; he was believed to have been bitten by a tick while “foraging for golf balls,” according to a 2009 paper in the Canadian Journal of Infectious Diseases and Medical Microbiology.
Since then, warming temperatures have fuelled the spread of blacklegged ticks across Canada, especially in the eastern provinces of Ontario, Quebec, Nova Scotia and New Brunswick. But even as Lyme-disease rates have soared, anaplasmosis has mostly laid low.
Something appears to have recently shifted, however. A few years ago, veterinarians in eastern Ontario started sounding the alarm about rising cases of anaplasmosis in dogs, according to Katie Clow, an assistant professor with the Ontario Veterinary College at the University of Guelph, who studies vector-borne diseases. (These are illnesses caused by pathogens transmitted to humans and animals through vectors such as ticks and mosquitoes.)
According to the Companion Animal Parasite Council, less than one per cent of dogs in the Kingston area tested positive for antibodies against anaplasmosis in 2019, which suggests a prior infection. Last year, 24 per cent – one in four dogs – tested positive.
Dr. Clow is also the lead investigator of a cross-country surveillance network trying to track the spread of ticks and the pathogens they carry. In 2019, only 1.1 per cent of ticks collected in the Kingston area tested positive for anaplasmosis, she said; since 2022, the percentage has been between 4 and 9 per cent.
“The changes we’ve seen in a short amount of time seem shocking,” she said. “From the tick perspective, we have these growing populations, they’re expanding, and now they’re transmitting multiple pathogens that are at risk to humans and other species.”
Kathleen Haché says keeping ticks away may become a part of the couple's regular life, similar to wearing sunscreen or applying mosquito spray.Ashley Fraser/The Globe and Mail
Today, Southeast Public Health – which captures Kingston and surrounding areas such as Prince Edward County – has Ontario’s highest infection rates for not just Lyme disease but anaplasmosis as well, according to Public Health Ontario data. So far this year, the health unit has reported 51 cases of anaplasmosis; every other health unit has reported between zero and three.
But in Canada, Nova Scotia remains the hardest-hit province for tick-borne illnesses, and anaplasmosis is no exception. In 2024, the most recent year for which there is federal data, 69 per cent of anaplasmosis cases were in Nova Scotia.
In Lunenburg County, home to Canada’s densest blacklegged tick populations, Nova Scotians like Katie Crowell have now had multiple infections of anaplasmosis. “I’m on my second round,” said the 40-year-old campsite operator.
For 67-year-old Greg Welsh, who runs a rescue animal farm in the region, he was showering in early April when he noticed a tick behind his knee, no bigger than the head of a pin. He flicked it off, watched it swirl down the drain, then thought nothing more of it.
About a week later, he became so sick that his skin turned yellow, he lost control of his bowels and had to crawl down the stairs to get help from his wife.
Mr. Welsh was diagnosed with anaplasmosis and prescribed antibiotics, which he took for three weeks. He has since learned of six neighbours who have also contracted anaplasmosis in the past few months, he said.
“I’ve had two massive heart attacks,” Mr. Welsh said. “This far outweighed the heart attacks.”
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In the coming months and years, a critical question for public-health researchers will be whether anaplasmosis follows a similar growth trajectory to Lyme disease, said Curtis Russell, a senior program specialist with Public Health Ontario who specializes in vector-borne diseases.
One silver lining is that antibiotics are very effective against anaplasmosis, Dr. Russell said. And the precautions that many Canadians are starting to take in order to prevent Lyme will also work for anaplasmosis, since both are spread by the same tick species – covering up ankles and legs, for example, as well as using tick repellant and doing regular tick checks.
Since contracting anaplasmosis, Mr. Welsh has started inspecting himself for ticks several times a day, something he never used to do. When venturing outdoors, he makes sure to wear his barn boots, which go up to his knee, sticking to cleared pathways and trails.
In the Ottawa Valley, Mr. Haché – who never even used to bother with mosquito spray – just ordered his first batch of tick repellant.
He and his wife are realizing they have to adapt.
“Wearing sunscreen, keeping the mosquitoes away … we do a lot of things for dangers that we are quite familiar with,” Ms. Haché said.
“We’re going to have to get to the stage where keeping ticks away from us becomes a part of regular life.”