Lyme disease is caused by bacteria transmitted through the bite of an infected tick.
Lyme disease was first identified in 1977. Many cases, at the time, were reported in children from the town of Lyme, Connecticut, United States. Ever since, thousands of cases have been reported across the United States, Canada and Europe.
In Canada, ticks that can transmit Lyme disease are found in parts of southern Manitoba, Ontario, Québec and British Columbia and parts of New Brunswick and Nova Scotland. In Québec, these ticks are concentrated in the Montérégie area.
In 2015, 159 cases of Lyme disease were reported in Québec, compared to:
Since 2011, there has been an increase in the number of people with Lyme disease in Québec, as well as the number of people that have contracted the illness in the province. The fact that Québec winters are less cold than they used to be partly explains this increase. The warmer climate enables the ticks to survive and grow more easily.
Ticks that transmit Lyme disease are known as “deer ticks” and “blacklegged ticks.” They live primarily in the forests, woods and tall grass.
Ticks feed on animal or human blood. Before feeding, their size can vary between 1 and 3 mm. Ticks can triple in volume when filled with blood, which makes it easier to spot them if bitten.
Tick bites are usually painless and often go unnoticed.
If you get bitten by a tick, you should immediately remove it. To know how, see the Removing a tick after a bite page. Place the tick you removed from your skin in a tightly closed container, like an empty pill vial. Write down the date and place you were at when bitten. Also note what part of your body you were bitten on. This information could be useful if you go see a doctor.
Lyme disease symptoms usually appear between 3 and 30 days after the bite of an infected tick.
Redness caused by Lyme disease. © Centers for Disease Control and Prevention (CDC)
The most common symptom is reddening of the skin in the area bitten. This symptom is visible in 60 to 80% of infection cases. The rash spreads fast, reaching 5 cm in diameter and can be ring-shaped or in the form of a target. Sometimes the rash can appear on several parts of the body.
Other symptoms may accompany this redness:
If you have one or more Lyme disease symptoms 3 to 30 days after being bitten, call Info-Santé 8-1-1 or see a doctor. Give the details of the bite as you noted them. If you go see a doctor, bring the tick with you in a sealed container. The doctor may decide to have it analysed.
Lyme disease can be treated with antibiotics prescribed by a doctor. The nature and duration of the treatment depends on the stage of infection and symptoms.
If the disease is not treated, it can cause problems in other organs or parts of the body, for example:
The problems may occur weeks, months or years after the bite.
To transmit Lyme disease, the tick must be infected by the bacterium Borrelia burgdorferi. The risk of contracting this disease is very low if the tick remains attached to your skin less than 24 hours, but this risk increases if the tick remains attached longer. It is, as a result, vital to remove the tick from your skin as quickly as possible. For more information, visit our Removing a tick after a bite page.
Ticks can cling to any part of the human body. They are often found in areas that are difficult to inspect, such as the groin, navel, armpits and scalp.
People with Lyme disease can contract it again.
Lyme disease cannot be transmitted from an infected animal to a human or through contact between 2 people.
Ticks do not jump, but they can cling to you or your pet during walks in the forests, woods and tall grass. The best way to prevent Lyme disease is to avoid tick bites.
How to avoid tick bites
How to spot a tick on your body
To reduce the presence of ticks in your surroundings
In Quebec, it has been mandatory to report Lyme disease infection cases since 2003. Any laboratory staff member or doctor who diagnoses the disease must notify the public health authorities.
Last update: June 8, 2016 4:18 PM
The information on this website by no means replaces the advice of a health professional. If you have questions regarding your health, contact Info-Santé 8-1-1 or see a health professional.