Those of you who live in the British Columbia Interior are likely already familiar with Rocky Mountain wood ticks (Dermacentor andersoni). They are the single most common tick species in the dry grassland ecosystems of the southern interior region and there are springs when the adults are so ubiquitous that recreating in the great outdoors is often followed by a de-ticking session, especially if Fido recreated with you.
It's safe to say that 2025 got off with a bang around here.
For the first time since this website launched more than a decade ago, I found the time and energy to reorganize the site's content and bring its design up to date. It was a monumental task not least because of the shear volume of research that has been indexed over the years. The adoption of new technology meant that I couldn't simply export records from the old site and import them into the new one and instead had to manually enter the data. But everything is there now, and many of the entries have been improved.
I think it's safe to say that Colorado tick fever (CTF) is one of those tick-borne illnesses that few Canadians have ever heard of -- and there's a good reason for that.
Borrelia miyamotoi disease (sometimes referred to as hard tick relapsing fever or HTRF) is one of those tick-borne illnesses that seems to have gone from completely unknown to widely discussed in the blink of an eye.
Tick paralysis is an appropriately albeit unoriginally named form of ascending paralysis that's been impacting residents of the southern BC Interior since at least as far back as the late nineteenth century and potentially even farther back than that.
In the decade or so that I’ve been covering tick-borne illnesses, I’ve heard a lot about co-infecting organisms, which are broadly defined as pathogens that can be transmitted to humans (or animals) along with Lyme bacteria when someone is bitten by a blacklegged tick. By far the most common ones I hear about are babesia, bartonella, and Borrelia miyamotoi although it remains unclear what percentage of Lyme disease patients are contracting these infections in Canada.
Babesiosis is a relatively new tick-borne illness in Canada that's really only just started to earn its way into the mainstream news. And yet, like Lyme disease and anaplasmosis, babesiosis cases are already on the rise in this country and are expected to escalate for many decades still to come.
I’ve been asked about Powassan virus (POWV) a lot in recent months, which is a bit odd since it can sometimes be difficult to get Canadians to recognize the presence of any tick-borne pathogens in this country, let alone one that’s rather obscure. I believe I can thank the media for the sudden rise in awareness of POWV. And while you’ll never catch me arguing that awareness is a bad thing, it tends to be more useful when it comes with the proper context. So let’s give it one.
It’s widely acknowledged that Lyme disease risk varies from one region to the next, but what’s not as well recognized is that a person’s chances of contracting non-Lyme tick-borne infections can also vary greatly between regions.
Rocky Mountain spotted fever (RMSF) tends to get little press in eastern Canada, largely because it’s extremely rare for a case to occur outside of the three western provinces. But if you happen to live in Saskatchewan, Alberta, or BC (or live anywhere in the rest of Canada and have extremely poor luck), RMSF is worth knowing about.
Tularemia, also known as rabbit fever, is a plague-like illness that was first documented in Tulare, California in 1911. We know little about tularemia in Canada except that it appears to be rare in this country. The first known Canadian case was recorded in Timmins, Ontario in 1930, and the disease is considered to be endemic in Central and Western Canada, less so in the east.