Lyme disease is caused by bacteria transmitted through the bite of an infected tick.

This 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 Scotia. For more information, see the Government of Canada web page Risk of Lyme disease to Canadians This hyperlink will open in a new window.

In Québec, available data confirms the presence of Ixodes scapularis tick populations infected by Borrelia burgdorferi, particularly in the following areas:

  • The north and west of Estrie
  • A large part of Montérégie
  • The south-west of Mauricie and Centre-du-Québec
  • The south-west of Outaouais

In 2017, 329 cases of Lyme disease were reported in Québec, compared to:

  • 177cases in 2016
  • 160 cases in 2015
  • 125 cases in 2014
  • 143 cases in 2013
  • 43 cases in 2012
  • and 32 cases in 2011

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. In 2017, three quarters of the cases reported to the public health authorities were contracted in Québec.  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 and tick bites

Ticks that transmit Lyme disease in North America are called Ixodes scapularis and are known as “deer ticks” and “blacklegged ticks”. They live primarily in forests, woods, tall grass and piles of dead leaves. 

Ticks have 3 stages of development : 

  • larva
  • nymph
  • adult 

At each of these stages, ticks must feed on animal or human blood to go on to the next stage.

Tick bites are usually painless and often go unnoticed. 

Before feeding, ticks can vary in size between 1 and 3 millimetres. Ticks can triple in volume when filled with blood, which makes them easier to detect in case of bites. Nymphs are smaller (the size of a sesame seed), often go unnoticed and generally stay attached to the person’s skin longer before they are detected. They are more active in the spring and summer months. Adult ticks are the size of an apple seed, which makes them easier to detect, and are more active in fall. 

After outdoor activity that may allow exposure to ticks, it is important to examine your skin to detect the presence of ticks and remove them as soon as possible. To know how, see the Removing a Tick After a Bite page. 


Lyme disease symptoms usually appear between 3 and 30 days after the bite of an infected tick.

The most common symptom is reddening of the skin. It appears in the area bitten, most frequently on the thighs, groin, armpits and torso. This symptom is visible in 70% to 80% of infection cases. The rash spreads rapidly day by day, extending over 5 centimetres, and can be shaped like a ring or a target. 

Other symptoms may accompany this redness:

  • Fever
  • Fatigue
  • Headache
  • Neck stiffness
  • Muscle and joint pain

When to seek medical help

In some circumstances, a healthcare professional could offer preventive treatment after a bite 

If you believe you have one or more of the symptoms of Lyme disease within 3 to 30 days after engaging in outdoor activities at risk of exposure to ticks, call Info-Santé 811 or consult a doctor. 

If you have noted a bite, provide the information you noted concerning the bite:

  • the part of the body that was bitten;
  • the date and the place you were when you were bitten.

If you consult a doctor, bring the tick, if possible, in a sealed container such as a pill container. 


Preventive treatment

If you were bitten by a tick in certain sectors of the Estrie, Montérégie or Outaouais regions, preventive treatment with antibiotics could be prescribed for you in some situations. 

For more information on the situation in these 3 regions, go to the regional websites: 

If you were bitten by a tick elsewhere in Québec, preventive treatment with antibiotics is generally not recommended. However, you must watch for symptoms to appear.  If you were bitten by a tick elsewhere in Canada or in the United States, in zones where there is a high risk of contracting the disease, preventive treatment with antibiotics could also be prescribed for you. 

To find out if it is preferable to consult a healthcare professional, contact Info-Santé 811.

Treatment of the disease 

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:

  • Joint problems
  • Heart problems
  • Neurological problems

These problems may appear within the weeks or months after you are bitten. 


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; 
  • the navel; 
  • the armpits;
  • inside or around the ears
  • behind the knees;
  • the hair.

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.

Protection and Prevention

Ticks do not jump or fly, but they can cling to you or your pet when you are in contact with plants during walks in the forest, woods and tall grass. The best way to prevent Lyme disease is to avoid tick bites.


How to avoid tick bites

  • Take your walks preferably on trails and avoid tall grass.
  • Use insect repellent on every exposed part of your body, avoiding your face. Closely follow the instructions for using mosquito repellent.
  • Wear a hat, closed shoes, a long-sleeved shirt and long pants.
  • Tuck your shirt into your pants.
  • Tuck your pants into your socks or boots.
  • After outdoor activities :
    • Take a bath or a shower as soon as possible, ideally within 2 hours after the outdoor activity, to check for the presence of ticks (see below). This will also allow you to remove ticks not solidly attached to the skin.
    • Carefully inspect your belongings (backpack, coat, etc.). This precaution seeks to avoid introducing a tick into your home, where it could bite a person or a pet.
    • Eliminate ticks on your clothes by putting them in the dryer at high temperature for 10 minutes. If your clothes are too dirty to be put in the dryer directly, wash them in the machine with hot water, ideally for at least 40 minutes. Then put them in the dryer at high temperature for at least 60 minutes. The clothes must be completely dry.
    • Also inspect your pets as they may bring ticks into your house. If you find ticks on a pet, remove them and consult a veterinarian if necessary. To obtain information and recommendations regarding ticks on your pets, consult the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation This hyperlink will open in a new window. website.

How to spot a tick on your body

  • Wear bright-coloured clothing during your walks. Clear colors make ticks more visible.
  • Examine your entire body after an outdoor activity. Ideally take a bath or a shower within 2 hours after the outdoor activity. Have another person help you or use a mirror to examine the least visible parts, such as the back. Also use shower time to examine your kids. If you find a tick, remove it by following instructions indicated in Removing a Tick After a Bite.

To reduce the presence of ticks in your surroundings

  • Cut tall grass and undergrowth around your house, and mow your lawn
  • Remove dead leaves, undergrowth and weeds from your lawn, around wood supplies and the shed
  • Place wood chip or gravel paths between lawns and wooded areas, patios and playgrounds. Paths should be at least 3 meters in width
  • Position play areas away from trees, in a sunny location
  • Stack wood neatly in a dry, sheltered area. This can deter rodents, which attract ticks. Rid your yard of old furniture and items

Special Conditions

In Québec, 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.