Canada

For years, medical experts have warned a rising number of Canadians are being exposed to ticks carrying an array of dangerous pathogens. Lyme disease is the most familiar — and by far the most common — but there's growing concern about lesser-known threats as well, from various bacterial infections, to the rare Powassan virus that claimed Harris's life earlier this year.

Case counts are rising, yet data remains thin, all while climate change is helping tick populations spread further north, putting even more of the population at risk. The question now, experts say, is whether awareness and surveillance efforts are keeping up with a growing threat.

"There's probably still more of [these infections] than what's being diagnosed … because the general public is probably not that aware of it, and healthcare providers aren't aware of it," said Dr. Isaac Bogoch, an infectious diseases specialist with the University Health Network in Toronto.

"The more you look, the more you find."