Tick numbers are on the rise in Canada, putting more Canadians on the lookout for Lyme disease. But a more serious tick-borne disease may be emerging -- one that many have never heard of -- that could pose an even bigger threat.
It’s called Powassan Virus and it’s transmitted by many kinds of ticks, including deer and groundhog ticks. Unlike Lyme disease though, which takes 24 hours to cause an infection after a tick bite, the Powassan Virus can be transmitted from a tick in as little as 15 minutes.
The one bit of bright news is that Powassan is still relatively rare in Canada, says Dr. Matthew Gilmour, the scientific director general of the Public Health Agency of Canada’s national microbiology laboratory.
A microscope photo of a tick in the entomology lab at the University of Rhode Island in South Kingstown, R.I. (AP/ Victoria Arocho)
“Thankfully, it’s actually in very few ticks,” he told CTV’s Your Morning Thursday.
“We’ve done a lot of testing of ticks, we’ve tested thousands of them, and we’ve found only a handful of ticks are carrying this virus.”
But the number of blacklegged ticks has expanded rapidly in Canada over the last 10 years, raising the possibility that more infected ticks could be in the tall grasses of Canada.
For those infected, it’s often difficult to diagnose a Powassan infection, since the symptoms are so similar to many other infections.
“An infection with Powassan starts out kind of general. One could have no symptoms whatsoever, or they could develop a fever or a headache,” Gilmour said. “From there, you could move off to more severe symptoms.”
Those serious symptoms include trouble speaking, confusion and lack of co-ordination. That’s usually a sign of an inflammation in the brain, either encephalitis or meningitis. There are no medications to treat Powassan and 10 per cent of cases involving brain infections are fatal.
Gilmour says the virus was first identified in the 1950s in a boy from Powassan, Ont., near North Bay, who became infected and died.
Since then, only 25 cases of infection have been identified – a tiny number in comparison to the 800 cases of Lyme disease that were diagnosed in Canada last year alone. In the U.S., the numbers aren’t much higher: only 75 Powassan cases have been reported.
But with warmer winters, public health officials in both Canada and northeastern United States say tick population are growing, which could lead to more tick-borne infections of all types.
Gilmour says the best way to fight Powassan Virus is to avoid getting bitten by ticks in the first place.
Wear long pants if you’re out on a hike
Use insect repellent
Checking your entire body for ticks after time spent in wooded areas
Carefully remove any you find as soon as possible
For those in rural areas, keep grass on your property short and rake up leaves
If you develop an unexplained fever and a headache after time in the woods, see your doctor