montreal breaks record for lyme disease cases

montreal public health recorded its highest number of cases of lyme disease ever in 2025. the agency recorded a total of 161 cases, 61 of which (38 per cent) were believed to have become infected in montreal. its annual report, published wednesday, comes a year after the island was declared a risk area — also known as an endemic zone — for lyme disease, an illness transmitted via black-legged (deer) ticks."the findings don't come as a huge surprise," said dr. nicolas sheppard-jones, medical lead for infectious disease public health emergencies with montreal public health. "we know that the ticks that carry lyme disease are spreading in an increasing number of regions in quebec, and that includes the region of montreal." of the 161 cases the agency recorded, 118 are suspected to have been infected within the province of quebec:

• montreal: 61 (38%)
• estrie: 22 (14%)
• montérégie: 12 (7%)
• laurentides: 10 (6%)
• lanaudière: 6 (4%)
• outaouais: 3 (2%)
• mauricie/centre-du-québec: 3 (2%)
• laval: 1 (1%)
• outside quebec: 41 (25%)
• unknown: 2 (1%)

montreal public health had recorded 113 cases of lyme disease in 2024. the agency suspects climate change is contributing to the increase in infections in the city over the past decade, since it allows for environments where ticks can thrive. previously, cases recorded in the city generally came from the united states or ontario, sheppard-jones said.

those most affected in 2025 were montrealers age 50-59 (26 cases) and 60-69 (24 cases). twenty-two cases were recorded among children age 0-14. men were more affected than women, at 57 per cent versus 43 per cent.nine people between the ages of 26 and 66 were hospitalized, representing six per cent of cases. five of them had heart symptoms, five presented skin symptoms, two had neurological symptoms and two had joint symptoms.ticks can be found in forests, wooded areas and tall grass, but also gardens and piles of dead leaves. "if you're just walking down the street, you are not going to run into a tick because ticks don't jump, they don't fly," sheppard-jones said. "there needs to be a contact between the human that's walking through vegetation." while ticks are more concentrated in the western and eastern tips of the island, there's a risk centrally as well, sheppard-jones said. seventy-six per cent of those affected in 2025 said they participated in outdoor activities in endemic areas. among those in montreal, 39 per cent reported gardening or yard maintenance. only 14 per cent of cases actually saw a tick on their skin. since public health expects the black-legged tick's habitat to continue to expand and for the concentration of ticks in affected regions to increase, the agency is calling for montrealers to adjust their behaviour accordingly.

precautions

according to the u.s. centers for disease control and prevention, clinical trials for a lyme disease vaccine against north american and european strains are underway. in the meantime, there are precautions that can be taken before, during and after outdoor activities to reduce the risk of a tick bite, sheppard-jones explained. he suggests using tick repellents and wearing long clothes.there are also ways to mitigate the risk during activities, such as by staying on marked paths, clear of vegetation. after an activity, it's important to do a tick check on yourself, children and animals, "including areas where ticks might like to hide, like the hairline, armpits, so forth," sheppard-jones said.showering within two hours of an outdoor activity can also potentially wash a tick away before it latches on. "all those together really can reduce the risk significantly of getting infected by a tick," sheppard-jones said.

if you get bitten

not all ticks carry diseases, sheppard-jones pointed out. removing them promptly can reduce the risk of transmission when they are infected. "it takes time for the bacteria to pass from the tick into your system," sheppard-jones said. the government of quebec suggests avoiding squeezing the tick's abdomen, because that can increase the risk of transmitting the disease. to remove it, grasp it with tweezers as close to the skin as possible. pull it gently but firmly, without twisting or crushing it. "if the head of the tick remains embedded in the skin, you can then gently remove it with the tweezers," the government website reads. "if you're using a tick puller, follow the manufacturer's instructions. if you can't remove the head, leave it in place and let the skin heal." it also suggests keeping the tick in an airtight container in case you need to show it to a health-care professional. write down the body part that was bitten and the date the tick was removed. wash hands and skin thoroughly with soap and water. montreal public health recommends calling 811 after a bite (or suspected bite), as some people may benefit from preventive antibiotics against lyme disease. the website etick.ca can also be used to submit photos of the tick for identification, which helps governments keep track of the situation.

what to watch for

symptoms of lyme disease typically appear within three to 30 days of a tick bite and can feel similar to the flu. "in three out of four people who are infected, a rash will develop at the site of the bite, and it's a pretty characteristic rash," sheppard-jones said. "it's about five centimetres in diameter or more, and it's ... present for 48 hours or more." if the disease goes unnoticed and untreated, it can spread to other parts of the body, like the heart, nervous system and joints."ideally, people recognize the risk of lyme disease, recognize the early symptoms of lyme disease ... and then as soon as they see those signs, they present to a health-care provider for a quick treatment," sheppard-jones said.kthomas@postmedia.com