Montreal recorded its highest number of Lyme disease cases in 2025

The Montreal Regional Public Health Department (DRSP) wants to raise awareness about the risk of being bitten by a tick and developing Lyme disease, even in urban areas. Last year, 161 cases were reported in Montreal, the highest number since 2003, the year the disease became reportable in Quebec.

The Eastern Townships remain by far the most affected region in the province. According to government figures, 859 cases of Lyme disease were reported between Jan. 1 and Nov. 1, 2025, including 385 in the Eastern Townships. 

With climate change, the number of regions where ticks carrying Lyme disease are found is increasing. Indeed, warmer temperatures allow ticks to remain active for longer periods and spread more widely. 

“With climate projections, of which I am not an expert, but the expectation is that this migration towards the north of ecosystems favorable to ticks will continue,” commented Dr. Nicolas Sheppard-Jones, medical director of the Emergency Health Service in Infectious Diseases at the Montreal Public Health Department, in an interview.

Of the 161 cases reported in Montreal, public health officials estimate that 38 per cent were acquired within the city limits. The main risk factor is engaging in outdoor recreation in an endemic area. 

“We’re not saying to stay home,” clarifies Dr. Sheppard-Jones. “We’re encouraging outdoor activities. However, there’s a change in our habits. Ten to 15 years ago, we didn’t have this same risk in Montreal. Now, this risk is present.”

Since 2024, the entire territory of the Island of Montreal has been considered at risk of exposure to ticks. 

Simple tips to avoid a sting 

How can you prevent a tick bite? Dr. Sheppard-Jones explains that ticks don’t jump. They need to be in contact with the vegetation where they live to attach themselves. “Ticks are found in forests, wooded areas, tall grass, and gardens. So, if you’re going to be doing an outdoor activity that might bring you into contact with vegetation, there are precautions you can take.” 

First, wear long clothing and apply insect repellent during the activity. When hiking, staying on the trail significantly reduces the risk of being bitten by a tick. 

After the activity, it is strongly advised to perform a complete body check, for yourself, your child, or your pet. In addition, taking a shower or bath within a few hours of the activity usually helps to dislodge the tick, adds Dr. Sheppard-Jones. 

According to data collected during epidemiological surveys, 55 per cent of cases were diagnosed early in the infection. A quarter of cases were diagnosed at more advanced stages (early disseminated stage) and 20 per cent at the late disseminated stage. At these stages, the disease can lead to various complications. 

What should you do if you get bitten by a tick?

The first thing to do if you have a tick on you is to remove it. This can be done at home or by a healthcare professional, such as a doctor or nurse. A pharmacist can also guide you through the steps to safely remove the tick, then conduct an assessment and, if necessary, prescribe a preventative antibiotic. 

“If you are bitten by a tick, symptoms generally appear between three and 30 days after the bite. Three out of four people who contract Lyme disease will experience a rash,” says Dr. Sheppard-Jones. It should be noted, however, that not every tick bite leads to infection. 

“If a person does not seek medical attention, the bacteria and the disease can spread to other parts of the body,” the expert continued. “The heart, for example, can be affected, as well as the neurological system and certain joints.” 

He advises people to call 8-1-1 to be guided through the next steps. “In some cases, certain individuals may be eligible for an antibiotic to prevent the symptoms of the infection. So, depending on your situation, the professionals at Info-Santé will be able to guide you and, if necessary, refer you to a healthcare professional for evaluation.”

As the hot summer temperatures approach, it’s not just the general public who need to be made aware of Lyme disease. Healthcare professionals do too. In June, the Regional Public Health Department (DRSP) sends out a “call for vigilance” to all its clinicians, urging them to be extra attentive to this disease and reminding them of the provincial guidelines for managing people who have been bitten, whether they are symptomatic or not. 

—The Canadian Press’s health coverage is supported by a partnership with the Canadian Medical Association. The Canadian Press is solely responsible for this journalistic content.

–This report by La Presse Canadienne was translated by CityNews