Lyme Disease risk areas are up from last year: Public Health Ontario

Estimated risk areas for Lyme disease in Ontario — and Windsor-Essex — have expanded this year compared to 2018, according to new data from Public Health Ontario. 

PHO says tick populations are continuing to expand — and climate change is part of the reason

An adult blacklegged tick.
An adult blacklegged tick. (Bertrand Guay/AFP/Getty Images)

Estimated risk areas for Lyme disease in Ontario — and Windsor-Essex — have expanded this year compared to 2018, according to new data from Public Health Ontario. 

Curtis Russell, a senior program specialist with the organization, works with local health units to help create the mapping project which outlines these areas for the province. 

"This is the most number of risk areas we've had," he said.

"What we're seeing is probably more ticks, and those populations of those ticks — they're spreading."

'Very hard to get rid of them'

The map is continuous, he explained. The organization does more tick surveillance each year, actively searches for ticks and as it comes across new areas, those zones are added to the map.

"Once ticks are established in an area, it's very hard to get rid of them. So once they're there, we just keep adding on to the risk map."

The mapping project focuses on the black-legged tick, which is the only kind in Ontario that can transmit Lyme disease to humans, he explained.

The estimated risk areas indicate spots where ticks are established as well as a 20km buffer zone around other locations where they could potentially spread.

Russell explained, however, that within those zones, they'll mostly be found in forested, deciduous areas — not city centres.

Climate change a factor

In Windsor-Essex, it was Point Pelee which was the main risk area in 2018. This year, most of the county is considered a risk area.

Lyme Disease Estimated Risk Areas Windsor-Essex

5 years ago
Duration 0:31
Featured VideoEstimated risk areas for Lyme disease has expanded in Windsor-Essex for 2019 compared to 2018.

According to research, Russell said climate change is the reason for the expansion. 

"Because the temperatures are getting warmer, and staying warmer, it allows them to get into new areas, and stay there, and flourish."

Some locals who enjoy being out nature, like local photographer Ray Akey, say the expanded risk zone won't stop them from getting outside.

"As soon as I get out of my van, I put my camera down, and I spray my legs, my back," he said. 

"Anything that's gonna brush against trees or anything like that. And keeps everything off luckily."

Windsor residents Funmi Olaniyan and Sara Tremblay say the expansion of the risk zone for the area won't deter them from going on hikes. (Katerina Georgieva/CBC)

For Windsor resident Sara Tremblay, ticks are of little concern to her.

"I think that ticks are just going to carry on doing what they've been doing forever. We're more aware now."

Tips from Russell on tick protection:

  • wear long sleeves, light-coloured clothing with everything tucked in
  • wear bug repellant
  • stay in the middle of trails
  • take a bath or shower after a hike
  • always do your checks after a hike because a tick could be as small as a poppy seed

As for future projections, Russell said it's difficult to predict how the temperatures are going to play out, but he expects to see more black-legged ticks and an expansion of their populations throughout the province.

Karen Cedar, of Windsor's Ojibway Nature Centre said no ticks have tested positive for Lyme disease at Ojibway Park this year so far.


Katerina Georgieva

Host of CBC Windsor News at 6

Katerina Georgieva is an RTDNA award winning multi-platform journalist for CBC News based in Windsor, Ont., with a passion for human interest stories. She has also worked for CBC in Toronto, Charlottetown, and Winnipeg. Have a news tip? You can reach her at