Deer ticks may carry Lyme disease, so the health unit is collecting them for study. (Victoria Arocho/Associated Press)

An increase in the number of deer ticks in Northwestern Ontario, which can cause Lyme disease, has prompted the Thunder Bay District Health Unit to spend more time on that problem and less on trapping mosquitoes.

Entomologist Ken Deacon says the risk of West Nile virus, carried by mosquitoes, is very low this year.

So, starting Tuesday, the health unit is putting more resources into collecting and studying deer ticks, also called the black-legged tick.

"The trend for the previous years has been from almost no ticks in 2005 to over a thousand ticks last year. I mean, we're over 500 ticks now, and we've got the rest of the summer to go," Deacon said. 

In spite of the many ticks being caught for study, the prevalence of Lyme disease — the illness carried by some deer ticks — remains low in the Thunder Bay district, he said.

Deacon says the crew uses something very basic to collect the ticks, but it works.

"It may sound really funny, but we drag a sheet of diaper flannel behind us on a road through the bush. But the nice thing about it is it's white, and it's really easy, and the ticks grab onto it, they really do," he said.

"This is something that's done elsewhere in Canada, particularly in Ontario, [but] this is the first time we've tried it here."

Up until this year, Deacon said, the health unit only collected ticks that were brought to it by the public.

Deacon said they've cut back to 12 mosquito traps from 19, and the ones they are eliminating are further away from the city.