About Lyme Disease in Canada

Kids lying in field

Lyme disease is a complex multi-system inflammatory illness caused by the bite of a tick infected with one of several closely related species of Borrelia bacteria. It's by far the most common tick-borne illness in Canada, but it's by no means the only one.

Our understanding of Lyme disease in Canada is in its infancy. The first breeding colony of blacklegged ticks was discovered at Long Point, Ontario on the north shore of Lake Erie back in the early 1970s and that colony was found to be infected with Lyme bacteria in the late 1980s. Since that time, many more of these breeding colonies have been found throughout southern Canada with hotspots having been identified in British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, and Quebec. The remaining provinces are expected to be colonized in the near future. Every year, more and more Lyme-endemic regions are added to the map and locally acquired cases of Lyme disease have now been reported in every province.

Lyme disease is projected to spread rapidly across Canada over the coming decades and many factors are driving this expansion, including climate change, forest fragmentation, declining biodiversity and migrating birds, which are estimated to distribute as many as 175 million blacklegged ticks across Canada each spring from two distinct populations in the United States -- the Northeast (whose ticks primarily wind up in Ontario, Quebec and the Maritimes) and the Midwest (whose ticks primarily wind up in the prairie provinces) -- as well as from established colonies within Canada. Western blacklegged ticks, which also carry Lyme bacteria and can transmit it to humans, are found in many regions of British Columbia.

I first began researching ticks and tick-borne illnesses when I was diagnosed with Lyme disease and relapsing tick fever in 2007. Back then, Canada-centric, peer-reviewed journal articles on ticks and the illnesses they carry were few in number. Much of what Canadians were being told about Lyme disease was borrowed from research done in the United States and it was unclear how or even if that research applied to the situation in Canada. To make things more challenging, the limited research that was being done in this country didn't appear to be finding its way to doctor's offices, public health units, or the general public, something that resulted in a disturbing disconnect between researchers and just about everyone else.

Thankfully, things are changing. In the past decade, an increasing number of researchers in every province (and representing an impressive array of disciplines) are applying their expertise to ticks and tick-borne illnesses. As a result, we are collectively learning an ever increasing amount about the unique situation we face here in Canada although we're still a long way from being able to make definitive statements about a great many aspects of Lyme disease and other tick-borne illnesses.

This website's goal is to catalogue all of the Canadian research on ticks, Lyme disease and related tick-borne illnesses so that anyone who wants to educate themselves can find the information they're looking for in one convenient place. Once you familiarize yourself with the papers indexed on this site, you'll discover there are a great many aspects of tick-borne illnesses that are currently either under-researched or not being researched at all in this country, proving that although we have come far, there is still a long way yet to go.

Vanessa speaks with host Wayne MacPhail about the complicated role climate change plays in the tick invasion of Canada on the Harrowsmith Radio Podcast.

Lecture: Lyme Disease in Nature

Projected Spread of Blacklegged Ticks

Webcast: Lyme Disease in Canada