Lyme disease threat increasing in Manitoba as black-legged tick population expands north

While the warm, mostly dry weather has helped dry out fields and keep the Red River from reaching feared flood levels, it has brought another yearly occurrence — deer ticks and an increasing threat of Lyme disease.

The number of cases of the inflammatory disease, which is spread by the ticks, rose once again year. And as the population becomes more widespread, that trend could continue. 

"We're getting at a point where we have them in greater numbers in places where they have been for a while and we see an expansion in the distribution," said Kateryn Rochon, an associate professor in the department of entomology at the University of Manitoba.

"We see them more north and more west than we used to see them as well." 

Rochon said deer ticks — also known as black-legged ticks — will likely continue their expansion, but it remains uncertain how far north the species can thrive. 

"You can expect more black-legged ticks in the future," she said. 

According to statistics from the province, 54 cases of Lyme disease were either confirmed or probable in 2018. That's up from 43 cases in 2017 and five in 2009 — the first year Lyme disease was deemed a nationally reportable infection. 

The province said exposures to Lyme disease have been recorded between March and December, with a peak between May and July, which according to Rochon is when adult black-legged ticks are most active. 

A provincial spokesperson said greater public and physician knowledge of the disease also could be behind the increase in cases. 

But Rochon said the growing threat shouldn't deter people from getting outside. 

Don't be afraid 

"People should stay with their good habits of taking advantage of the summer and the fall in Manitoba," said Rochon. "Don't stay in your house because you're afraird." 

Rochon said wearing a repellant with DEET, as well as appropriate clothing, can help deter ticks from accessing or biting your skin. 

"People who were born and raised in Manitoba have always lived with ticks," she said. American dog ticks, more commonly known as wood ticks, have been around for a long time and generally don't pose any risk to humans. 

"Ticks are just a fact of life and usually they don't cause any trouble … but now that we've got more and more black-legged ticks, you can't just pick the tick off and keep going," she said. 

Maps, tracking tools 

Jan Cmela was diagnosed with Lyme disease six years ago and is part of a support group for others with the illness. She says she still has some symptoms lingering from the disease.

She stressed the importance of tick awareness and prevention. That can include using tick repellent, wearing light clothing, tucking clothing in and doing tick checks after potential exposure.

And if you feel ill afterward, get yourself to the doctor, she advised. The symptoms vary widely and can include dizziness, fatigue, flu-like symptoms or rashes — which may not necessarily resemble the bull's-eye rash commonly associated with Lyme disease.

"Early diagnosis is huge. People that don't catch it right away, they're the ones that are sick longer," she said. 

"Any tick that's attached that you get symptoms for after, you need to go to the doctor."

The province has published a surveillance map, which shows where people are most at risk of coming into contact with black-legged ticks.

Cmela said it's important to take steps against ticks even in areas where they don't show up on the map, in case the ticks have been carried by other animals.

The province also has a tick tracker website, where people can submit photos, in an effort to track which type of ticks are in certain areas of the province.

"Start now with good habits of personal protection and checking yourself," said Rochon. "If there's no snow outside, check yourself. You never know."