Be vigilant checking for ticks despite late start to the spring, Thunder Bay entomologist says

An entomologist in Thunder Bay, Ont., says a slow start to the tick season shouldn't keep people from being mindful of the critters when enjoying outdoor activities this summer.

The late snow melt in northwestern Ontario has meant that the springtime emergence of ticks has been delayed, said Ken Deacon, the Thunder Bay District Health Unit's surveillance of vector-borne disease program coordinator.

Deacon said ticks are typically submitted to the health unit beginning in late April, but the first ones this year came closer to the middle of May.

The number of ticks submitted to the health unit by members of the public is lower so far this year than at this point in 2021, though he said that isn't necessarily a sign that the tick populations are down.

Deacon said black-legged ticks, which can carry and spread Lyme disease, typically make up about 10 per cent of ticks collected in the area. 

Wood ticks, which have white or ivory markings, are more common in the Thunder Bay area. The local range of those ticks seems to be increasing, Deacon added.

Deacon said the COVID-19 pandemic ended a program where ticks submitted by members of the public would be tested. The only ticks that are now tested for Lyme disease are collected by a summer student through active surveillance, so there can be certainty about where they originated.

Testing has helped identify areas where the black-legged ticks are relatively prevalent, he said.

"Last year the majority of ticks we collected at Rabbit Mountain did have Lyme Disease, it really does mean it is a hot spot," he said.

Deacon said prior to Thunder Bay being identified as an area of risk, it was difficult for people to be confirmed as having Lyme disease.

The distinctive bullseye shaped rash is a common indicator, but isn't always present in positive cases, he added.

Local monitoring of ticks has led to increased awareness that the insects are present in the area, and that there is a risk of Lyme disease transmission, he said. 

"It means the disease is treated more appropriately by the medical professionals. They're aware, they've talked about it, and here it is, there really is ticks and Lyme disease in the area."

In 2021, provincial public health units across Canada reported a total of about 2,850 human Lyme disease cases. That's the most in available data dating back to 2009.