Tick news.

The Public Health Agency of Canada (PHAC) reported 5,809 confirmed Lyme cases in 2024, a national rate of 14.1 per 100,000. Ontario leads in total cases and Nova Scotia leads per capita. See the numbers by province, month, and age.

Blacklegged tick nymphs (the life stage behind most Canadian Lyme cases) are at peak activity from late April through June in southern Ontario, southern Quebec, southern Manitoba, and the Maritimes. PHAC’s risk maps grow every year. Areas that weren’t Lyme risk zones 5 years ago often are now.

If you spend time in long grass, leaf litter, or forest edges anywhere in those regions this spring, assume blacklegged ticks are present. A daily tick check in May and June catches nearly every bite before the 24-hour transmission window closes.

The Lone Star tick (Amblyomma americanum), the one with a single bright white dot in the centre of the adult female’s back, has expanded its established range in southwestern Ontario over the past several seasons. Strays turn up further north, almost certainly carried in on migratory birds.

Lone Stars are aggressive biters and the primary North American vector for alpha-gal syndrome (a delayed allergy to red meat that develops after repeated bites). Canadian cases are still rare. If you find a tick with a clear white dot in the centre of its back, submit it to eTick.

eTick.ca, run by Bishop’s University, is a Canadian site where the public submits tick photos for expert identification. Submissions are free, you usually get an answer within a few days, and your submissions help Health Canada track where ticks are spreading.

If you remove a tick, photograph it (or save it on a card) and submit through etick.ca. The species comes back to you, and the record goes into the national picture of where ticks are.