Lyme Disease

Lyme disease is an infection that can affect the entire body. It is caused by the bacteria Borrelia burgdorferi and is transmitted to humans by deer ticks.


Infection is transmitted through the bite of an infected deer tick. In North America, ticks are usually found in wooded areas. Disease-carrying ticks however, are limited to certain areas. Although the species of ticks responsible for Lyme disease are found across Canada, they are most prevalent in Eastern Canada.


Early symptoms of Lyme disease usually appear within 3 to 30 days. If left untreated, symptoms will continue to progress over weeks and months. Lyme disease is generally divided into 3 stages:

  1. Localized "bull's-eye" rash with flu-like symptoms (e.g. fatigue, headache, chills, fever, muscle and joint pain)
  2. Neurological manifestations (e.g. extreme fatigue, weakness, muscle and joint stiffness) and cardiac abnormalities (e.g. irregular heartbeat)
  3. Joint problems and chronic neurological symptoms

If you visit or live in an area where Lyme disease is a risk, seek medical attention if one or more of the following symptoms develop:

  • Redness > 5 cm
  • Multiple skin lesions
  • Unusual muscle or joint pain
  • Numbness, weakness or paralysis
  • Fatigue, headache and fever


To reduce the risk of being bitten when walking in infested woods or overgrown brush, wear long pants tucked into socks, long-sleeved shirts with tight-fitting cuffs and closed shoes. Wear long, light-coloured clothing as ticks are easier to see on a light background. Apply insect repellent (DEET) on areas of exposed skin and on clothing.

Upon returning from a potentially tick-infested area, check yourself, others and pets for ticks. To reduce the risk of infection, remove the tick with tweezers by grasping it as close to the skin as possible (do not squeeze its body) and pulling straight out, without twisting. Most outdoor equipment and clothing stores sell tick removal tools. The chance of contracting Lyme disease is very low if the tick is attached to the skin for less than 24 hours.


Antibiotics are used to treat Lyme disease. They must be prescribed by a physician.

For more information:

Public Health Agency of Canada
