The presence of blacklegged (deer) ticks in the Haut-Saint-Laurent and much of the Montérégie is so widespread that the arthropods are now considered to be endemic to the region.
During a presentation at the Lac Saint-François National Wildlife Area in Dundee on May 21, Dr. Alex-Ane Mathieu, a consultant physician in the infectious diseases, threat management, and environmental health sector with the Centre intégré de santé et de services sociaux de la Montérégie-Ouest (CISSSMO), noted that a significant number of the ticks in the region are infected with Lyme disease. She confirmed that the region’s elevated risk of exposure to ticks meant the number of diagnosed cases of the disease is also on the rise.
In 2021, at least 709 individuals were diagnosed with Lyme disease including five people in the Haut-Saint-Laurent. “Proportionally, the Haut-Saint-Laurent is one of the areas with the highest rate per population,” said Mathieu, noting “The risk is quite elevated here in comparison to other areas of the Montérégie.”
Mathieu explained there are 12 types of ticks in Quebec, but only the blacklegged ticks transmit Lyme disease. The arthropods, which are part of the arachnid family, are not hatched carrying the bacteria that causes Lyme disease (Borrelia burgdorferi). They become carriers of the disease after biting an animal (most often a rodent) that is infected. They don’t jump or fly, but they climb on vegetation and attach themselves to passing animals or humans who brush against them.
The warming climate has allowed the ticks to migrate further north. “We did not have Lyme disease here around 20 years ago,” said Mathieu, who notes doctors are more widely aware of the disease and its symptoms and public health officials are closely monitoring the presence of ticks. “The ticks are everywhere,” she said, suggesting people can be bitten by a tick while doing traditional outdoor activities such as hiking, or simply while gardening outside their homes.
Ticks are most often found on areas of the body that are more humid, in folds of skin, or where they are well-hidden. Mathieu highlighted the importance of doing self-examinations and examining children’s bodies following any exposure to the outdoors. It is also a good idea to shower and to wash all clothing that was worn outside.
“They are not able to bite if they do not have access to our skin,” she explained, suggesting closed shoes, socks, and long pants can help prevent tick bites. Insect repellant with DEET can also help deter ticks. Mowing the lawn and keeping vegetation trimmed within a three-metre buffer between wooded areas and yards is also a good preventive measure.
Ticks can stay attached over several days once they have bitten an animal or person. The risk of being exposed to Lyme disease increases the longer they are attached. According to Mathieu, it takes at least 24 hours to transmit the bacteria, but she admits it can be difficult to know how long a tick has been attached.
It is important to remove the tick without crushing or squeezing it as this can increase the risk of transmission. Using fine-tipped tweezers or tools especially designed to remove ticks, grasp the tick as close to the skin as possible and pull upwards. Once it is removed, clean the site, and place the tick in a container or take a photograph of it. It is possible to report the tick through the website eTick.ca, which is a public platform for image-based identification and monitoring of ticks in Canada. The site includes an interactive map showing where people have been bitten by ticks, as well as photographs to help identify them, plus information and resources.
Mathieu advised those who were unsure whether to seek medical attention could call 811 to see whether they should be given post-exposure prophylaxis, a preventive treatment that can be taken up to 72 hours after being bitten to reduce the risk of developing Lyme disease. She noted the recommendation for doctors in this area is not to send ticks to be tested. “If you have a tick from this area, we know the risk is very high and so we give the treatment,” she explained.
It can take up to 30 days for symptoms to appear; these can include a rash or redness at the site that expands progressively and lasts for more than three days. Mathieu suggested drawing a circle around the bite to better monitor any changes. Other symptoms may include headache, fatigue, fever, and muscle and joint pain. If untreated, Lyme disease can progress to cause more severe symptoms including neurological or cardiac problems as well as painful swelling in joints and numbness or pain in the body or limbs.
Lyme disease is treated with a common antibiotic which is very effective if administered quickly. Mathieu said there was research being conducted into long-term implications of Lyme disease and symptoms that continue following treatment, while reiterating the disease is being closely monitored by the medical community.
