Lyme disease continues to rise in Quebec and climate change is partially to blame

Isaac Olson · CBC News

· Posted: May 22, 2025 4:00 AM EDT | Last Updated: 8 hours ago

Cases of Lyme illness and different tick-borne illnesses person been expanding successful Quebec for much than a decade, and experts accidental clime alteration is partially to blame.

With expanding temperatures, ticks are becoming much established, particularly successful confederate Quebec, said Kirsten Crandall, a technological advisor with the Institut nationalist de santé publique du Québec (INSPQ).

And with big animals moving north, beryllium they birds oregon deer, ticks are covering a broader range, she said. This is particularly existent for black-legged ticks which tin transmit Lyme, she added.

"I deliberation we volition decidedly beryllium continuing connected that emergence successful the fig of antithetic tick-borne diseases," said Crandall. "Lyme illness evidently being the 1 with the astir lawsuit numbers."

Lyme illness is caused by a bacterium transmitted by the wound of black-legged ticks. The archetypal grounds is usually a azygous circular rash.

"Stage 2 and Stage 3 of Lyme illness tin impact your heart, you tin person neurological symptoms," said Dr. Donald Vinh, an infectious illness specializer astatine the McGill University Health Centre (MUHC).

"When it comes to those stages determination are antibiotics, but they thin to beryllium much intravenous types of antibiotics. So, it's truly important to forestall it."

Number of cases rising

The fig of declared cases of Lyme illness grew from 127 successful 2014 to 653 successful 2023. But not each were caught successful the province. In 2014, 66 cases were acquired successful Quebec. In 2023, that fig jumped to 562, oregon 86 per cent.

Last year, determination were 681 cases declared successful Quebec, with 568 infections acquired successful the province. 

As of May 14 of this year, determination were 61 reported cases, compared with 68 successful the aforesaid play past year. 

Jade Savage, an entomology prof astatine Bishop's University successful Sherbrooke, said Quebec had an aboriginal outpouring past year, which meant ticks were progressive sooner. This year, outpouring has travel aboriginal — meaning the ticks' enactment is later.

Vinh said Quebecers should expect the yearly totals to support rising.

While accrued wood excursions and not enough vigilance may play a role, Vinh said different origin is greater consciousness among health-care providers that Lyme illness is present endemic successful confederate Quebec.

The black-legged tick colonisation itself has besides been growing.

Last year, the INSPQ mapped the projected dispersed to assistance communities and governments program for the coming decades.

The maps amusement ticks expanding successful areas wherever they are already recovered and into bluish and eastbound regions wherever they are not usually seen, including Saguenay, the Lower St. Lawrence and the Gaspé.

Crandall said rising temperatures volition fto tick populations thrive adjacent successful places that are typically cooler year-round. 

Black-legged ticks tin go progressive aft conscionable a fewer consecutive days supra 0 C. Most Lyme infections are acquired successful outpouring and aboriginal summertime erstwhile young ticks are successful the nymph signifier and are overmuch harder to spot than big ticks.

Adult ticks are easier to spot and are much progressive successful the fall.

Crandall said Lyme disease's large endemic regions are the Outaouais, Montérégie and the Eastern Townships. She said cases are besides cropping up on the St. Lawrence River valley.

According to the Health Ministry, determination are lone 4 Quebec regions wherever ticks aren't established: Côte-Nord, Nord-du-Québec, Nunavik and Terres-Cries-de-la-Baie-James. However, the ministry adds, not each established tick populations transportation Lyme.

An established tick colonisation is 1 that returns and continues to thrive aft winter.

Less worry, much prevention

While cases acquired successful Quebec are rising, Crandall said Lyme illness isn't needfully thing to interest about, but it is thing to accommodate to. That's wherefore the INSPQ and Health Ministry are moving to amended the nationalist astir tick wound prevention, Crandall said.

Information astir ticks, Lyme illness and tick wound extortion tin beryllium recovered connected the Health Ministry's website. 

Savage launched eTick.ca successful 2017 with INSPQ and the Public Health Agency of Canada. The tool, which works arsenic an app oregon connected the website, present serves the full country, letting radical study and place ticks by uploading a photo. The tract besides offers proposal connected preventing bites.

Although 2025 tick reports are disconnected to a dilatory start because of cooler upwind and aboriginal spring, she does not expect that to impact the remainder of the season. Last twelvemonth saw a grounds fig of submissions, though that partially reflects the app's increasing popularity.

For each 100 submissions, arsenic galore arsenic 75 per cent are identified arsenic black-legged ticks. They proceed to determination into caller areas, transported by birds, cervid and different hosts, Savage said.

"They support connected expanding and they support connected being much numerous, but that is not needfully a afloat linear process," she explained.

"Some years, we volition spot more. Some years we spot less. But the semipermanent inclination each points to a continuous expansion."