Two Grey-Bruce areas added to provincial Lyme disease map

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Two new areas of Grey-Bruce have been added to Public Health Ontario’s “estimated risk areas” for Lyme disease due to the discovery of blacklegged ticks, which transmit the disease.

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There are now three areas in the two counties identified on Public Health Ontario’s updated Lyme Disease Map after blacklegged ticks were found through drag sampling. The areas overlap each other and are all located on the western part of the counties near the Lake Huron shore, including parts of Northern Bruce Peninsula, South Bruce Peninsula, Georgian Bluffs, Saugeen Shores, Arran-Elderslie and Kincardine.

While the two new areas have been added after the ticks were found as a result of Grey Bruce Public Health’s surveillance work in 2022, the health unit said there is a chance of encountering infective ticks almost anywhere in the province. The areas are calculated as a 20-kilometre radius from the centre of a location where the ticks are found, with the map displaying such areas across much of southern Ontario.

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The health unit also noted that not all blacklegged ticks carry the bacteria that causes Lyme disease and not everyone who is bitten by an infected tick will develop signs and symptoms of the disease.

“While the risk of getting Lyme disease remains low, we’re asking residents to take simple measures to protect themselves from tick bites while enjoying the outdoors,” GBPH Senior Program Manager Andrew Barton said in the release. “It is important to be aware of the areas where blacklegged ticks are known to live or in potential tick habitat, such as wooded areas, shrubs, tall grass, or leaf piles.”

The ticks, which feed on and are transported by migratory birds and animals, transmit the disease — caused by the bacteria B. burgdoferi — through their bite. Early symptoms of Lyme disease can include fever, headache, muscle or joint pain, fatigue and a bull’s-eye rash. If caught early it can be effectively treated with antibiotics, and anyone with symptoms should consult their healthcare provider.

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The chance of encountering a blacklegged tick in Grey-Bruce has increased over the years, along with the number of Lyme disease cases in Ontario, the release said.

In 2021 there were 1,455 cases of Lyme disease across Ontario, a rate of 9.6 cases per 100,000 people.

The Ontario Lyme Disease Map assists health units as they conduct Lyme disease case investigations and provides primary care providers information when considering potential exposures to blacklegged tick bites, the release said.

There is post-exposure prophylaxis available to prevent Lyme disease for those who have been bitten. Public health follows up with all residents diagnosed with Lyme disease, the release said.

To prevent Lyme disease by avoiding tick bites, the health unit recommends: using bug repellent containing DEET or Icaridin; wearing light-coloured clothing; tucking your shirt into pants, pants into socks and wearing closed-toe shoes; walking on clear paths; using a sticky roll brush to remove ticks from clothing before getting into the car; showering or bathing shortly after being outdoors; and checking your full body, children, gear and pets for ticks.

Those who are bitten by a tick should remove it immediately as in most cases infected ticks must be attached to a person for at least 24 hours to pass on the bacteria. Details on how to remove a tick can be found at