Lyme disease may be more common, but this tick-borne disease is on the rise in Canada

Tick ​​experts are warning Canadians to be alert for symptoms of a tick-borne disease whose cases have been steadily increasing over the past 15 years.

Anaplasmosis is an infection that affects humans and animals and is caused by the Anaplasma phagocytophilum bacteria and spread by ticks.

In the early 2000s, provinces and territories began reporting a handful of human cases each year, but experts now warn they are seeing up to 500 cases a year in the regions where anaplasma-carrying ticks live, although not all of them do. necessarily complete clinical cases of the infection.

“It’s kind of the new kid on the block,” said Heather Coatsworth, research scientist for the Public Health Agency of Canada’s National Microbiology Laboratory in an interview with Dr. CBC’s host Brian Goldman The dose.

Ticks carrying anaplasmosis are mainly found in Nova Scotia, Quebec and Ontario, although cases have been reported in Manitoba and Alberta.

Symptoms and transmission

Anaplasmosis is a disease caused by a bacterium that infects white blood cells in humans and animals.

Early symptoms include fever, chills, headache and fatigue. If left untreated, longer-term symptoms include respiratory failure, anemia, liver disease, and in severe cases, death.

“That’s especially common in people with weakened immune systems, but also in children and the elderly,” Coatsworth said.

It takes about 18 hours for a tick to infect the host with the bacteria.

“Since it is a blood-borne disease, it can also be transmitted through blood transfusion [and] solid organ donation,” said Coatsworth.

“And there is the hypothesis that it can also be transmitted from mother to baby.”

The first case of anaplasmosis in a Canadian was reported in 2009.

How does anaplasmosis compare to Lyme disease?

Anaplasmosis shares common early symptoms with Lyme disease, including flu-like symptoms.

In fact, the same ticks that carry Lyme disease – usually black-legged and western black-legged ticks – spread anaplasmosis by biting people.

Sometimes researchers have encountered ticks co-infected with Lyme disease and anaplasmosis.

A key difference between the symptoms of the two diseases is that anaplasmosis lacks the telltale bull’s-eye rash that occurs at the site of the bite of a tick carrying Lyme disease, Coatsworth said.

However, the same antibiotic – doxycycline – can be used to treat both tick-borne diseases.

Once treated for anaplasmosis, patients typically recover without symptoms after treatment, such as arthritis, which occurs in some patients with Lyme disease.

According to Coatsworth, Lyme disease is still more common than anaplasmosis at this time, with about 2,500 human cases in 2023, according to Health Canada.

Exact national statistics on anaplasmosis are not currently available as it only became a nationally notifiable disease in April 2024, meaning cases must now be reported to public health authorities.

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Ontario is now tracking three additional tick-borne diseases

A warming climate means a larger tick population and more tick-borne diseases in Canada. Ontario is already tracking cases of Lyme disease, but from now on it will also be tracking three other tick-borne diseases, including anaplasmosis, babesiosis and powassan virus disease.

How to prevent anaplasmosis

There is no vaccine that prevents the transmission of anaplasmosis, so avoiding bites is the best way to prevent tick-borne diseases.

“If you avoid being bitten by a tick or deal with a tick infection quickly and get the tick off, that will help with anaplasmosis, Lyme disease… and all the not-fun diseases that ticks transmit,” says Vett Lloyd , a biology professor at Mount Allison University who runs a drawing lab.

Bug sprays like DEET that specifically target ticks — rather than just mosquitoes — are often the most effective at preventing bites, Lloyd says.

Avoiding skin contact with lawns and regularly checking for ticks in wooded areas and while gardening or spending time in long grass can also reduce the risk.

“You’re looking for something that looks like a freckle, but unlike a freckle, [ticks have] legs,” Lloyd said.

If you do get bitten, tweezers are useful to remove ticks, Lloyd said. She recommends holding on to the tick in case it needs to be tested later.

Tucking socks over pants, wearing long sleeves and spraying clothing with the insecticide permethrin the night before you go outside can help prevent tick bites, Coatsworth said.

Online tools such as eTick can help identify different tick species and areas at risk.

LOOK | Insect-borne infections are increasing due to climate change:

Insect-borne infections are increasing due to climate change

Insect-borne diseases that infect humans, such as Lyme disease and West Nile virus, are on the rise in Canada. Shorter, less severe winters due to climate change have allowed these insects to expand their range.

If you’re bitten, it’s important to watch for the sudden onset of flu-like symptoms, Coatsworth said.

“If you know you’ve been bitten by a tick and then suddenly develop flu-like symptoms a few days later, that’s an indication that you should seek medical attention sooner rather than later,” she said.

Still, Lloyd says Canadians shouldn’t let fear of ticks stop them from enjoying summer in nature.

“Go outside, enjoy it and then check for ticks,” she said.