Grey Bruce Public Health encourages residents and visitors to take steps to prevent tick bites while outdoors, particularly in locations where ticks typically live, such as in or near wooded or bushy areas, tall grass, or piles of leaves.

This annual reminder, which follows the return of warmer weather in Grey-Bruce, coincides with the release of Public Health Ontario’s 2024 Ontario Blacklegged Tick Established Risk Areas Map, formerly the Ontario Lyme Disease Map: Estimated Risk Areas.

The updated map includes a new ‘Estimated Risk Area’ in Grey-Bruce – a location where blacklegged ticks, which can transmit the bacteria that causes Lyme disease to people, have been identified or are known to occur and where people could encounter them. The new ‘Estimated Risk Area,’ in central Grey-Bruce, brings to four the total number of such risk areas in the two counties.

“It’s important to stress that these are estimated risk areas only and infective blacklegged ticks can be found pretty much anywhere in Ontario, especially if the habitat is ideal for these poppy-seed-sized arachnids. Because of this, people should take precautions to prevent tick bites whenever they’re enjoying the outdoors. Preventing tick bites is the best way to prevent Lyme disease,” says GBPH Senior Public Health Manager Andrew Barton.

Lyme disease, a relatively rare vector-borne illness in Canada, is caused by the bacterium B. burgdoferi, which blacklegged ticks can carry. People can get Lyme disease if an infective blacklegged tick bites and then feeds on them long enough to transmit the bacteria – in most cases, this takes at least 24 hours.

Not all blacklegged ticks carry the bacteria and not everyone who is bitten by an infective tick will develop signs and symptoms of Lyme disease.

In 2022, there were 1,490 cases of Lyme disease throughout Ontario, which represents a rate of 9.9 cases per 100,000 people.

The updated Ontario Blacklegged Tick Estimated Risk Areas map assists Public Health Units as they conduct Lyme disease case investigations and provides primary care providers with valuable information when considering potential exposures to blacklegged tick bites.

Estimated risk areas are calculated as a 20-kilometre radius from the centre of a location where blacklegged ticks were found through drag sampling. The new estimated risk area in Grey-Bruce was established in response to the results of GBPH’s 2023 tick surveillance.

The best way to prevent Lyme disease is to avoid tick bites by: 

• 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.

If bitten by a tick, remove it immediately. Information on how to remove and identify a tick can be found on Health Canada’s Lyme Disease webpage.

Early Lyme disease symptoms can include fever, headache, muscle/joint pain, fatigue, and a bull’s-eye rash. Residents should consult a healthcare provider if experiencing these symptoms.

If caught early, Lyme disease can be effectively treated with antibiotics. Eligibility information for post-exposure prophylaxis to prevent Lyme disease is available here. GBPH follows up with all residents diagnosed with Lyme disease.