Ottawa considered at-risk area for lyme disease, warns public health

Ottawa Public Health has stopped collecting ticks after it found a high number of the arachnids within the city carry Lyme disease.

1 of 3 ticks found to carry Lyme disease bacteria last year

Ottawa is considered an at-risk area for the blacklegged tick, which can transmit lyme disease to people. (Bertrand Guay/AFP/Getty Images)

Ottawa is considered an at-risk area for Lyme disease and Ottawa Public Health is warning people to take precautions when out-and-about in the city. 

Officials stopped collecting ticks and testing them after the number of the arachnids with Lyme disease surpassed the 20 per cent threshold, the health agency said.

In 2016 and 2017, more than one-fifth of blacklegged ticks tested in Ottawa carried the bacteria.

In a three-year study in Ottawa, researchers from the University of Ottawa found one in three ticks carried Lyme disease bacteria. (Robyn Miller)

The whole city falls within that at-risk area, said Michelle Goulet, an inspector with Ottawa Public Health.

The number of reported cases of Lyme disease in Ottawa doubled to 168 in 2017 from 74 in 2016.

However, the number of cases of Lyme disease dropped in 2018, even as the percentage of ticks carrying the bacteria increased.

The number of reported cases in 2019 isn't yet known, said Goulet.

A map produced by Public Health Ontario shows various Lyme disease risk areas across the province. The Ottawa area is one of those areas estimated to be at risk. (Public Health Ontario)

Canada first began monitoring the spread of Lyme disease in 2009. In 2017, two-thirds of cases came from Ontario. 

Nymphs are usually the size of a poppy seed and more active in the spring and summer, while adult ticks are around the size of a sesame seed and are usually more active in the fall, according to information from the Quebec government.

A 2019 map from Public Health Ontario shows a large swath of southern and eastern Ontario is considered a Lyme disease risk area.

Preparing for the outdoors

To help prevent ticks from attaching to the skin, Goulet suggests people wear long clothing, tucking pants into socks and shoes and wearing an insect repellent containing Deet or Icardin.

"Make sure that you're staying on the path and staying out of the woods and out of the tall grasses," she said.

When returning home, do a tick check as soon as possible.

"Check in certain parts of your body, like under your armpits, in your groin, behind your knees, between your toes, under your hairline," she said.

Don't forget to check any pets that venture outside, because ticks can attach to their fur and be brought into the house, she said.

Removing a tick

If someone finds a tick on them that has been attached for more than 24 hours, or looks fully or partially engorged, Goulet suggests going to the doctor immediately. 

If the tick has been attached for fewer than 24 hours or is not inflated, it can be removed using fine-pointed tweezers. 

Ottawa Public Health suggests squeezing the tick's head and pulling hard, but slowly, to remove the whole tick, and being careful not to twist or rotate the tick.

People should not use a match or lotion on the tick, the health agency said.

Not all ticks are dangerous

A "bull's eye" rash is one of the symptoms someone can get after being bitten by a tick that carries Lyme disease. (CBC)

There are different types of ticks across Ottawa, but only blacklegged ticks, also known as deer ticks, carry lyme disease, Goulet said.

According to Health Canada, the symptoms of Lyme disease include a "bull's eye" rash, fever, fatigue, muscle or joint aches or swollen lymph nodes.

Can't tell if the tick is a blaclegged tick?  People can submit a photo of the tick to this website and they can help identify the type of tick.

With files from The Canadian Press and Radio-Canada