Lyme Disease


What it Lyme disease?

Lyme disease is a serious bacterial illness caused by infection with Borrelia burgdorferi sensu lato. B. burgdorferi is a tiny, spiral shaped bacteria most commonly transmitted to humans through the bite of infected ticks. If caught early, Lyme disease is frequently treatable with an appropriate course of antibiotics. However, if undetected and left untreated, the infection often disseminates throughout the body, becoming increasingly severe and difficult to treat. Currently, Lyme disease is one of the fastest growing epidemics in Canada (and around the world), seeing more new cases annually than breast, colorectal, and lung cancer.


How is Lyme disease transmitted?

Lyme disease is most commonly transmitted through the bite of infected ticks. In Canada, the most common culprits for transmission are the black-legged tick (Ixodes scapularis), and the western black-legged tick (Ixodes pacificus). Outside of these two species, transmission has been reported from a number of other hard-bodied ticks such as Ixodes angustus, and the lone-star tick (Amblyomma americana). Generally speaking, soft-bodied ticks are not commonly associated with the transmission of Lyme disease, but can be vectors for a number of equally relevant tick-borne illnesses.

Please consult the tick ID guide (Source: CanLyme) to identify the tick that you have come into direct contact with.


What are the symptoms of Lyme disease?

Lyme disease can present with a complex array of symptoms, ranging widely in severity. Often refered to as the “Great Imitator”, Lyme disease is notorious for mimicking and masking a variety of complex illnesses, including autoimmune disorders such as hashimoto’s disease, early Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS). A person infected with Lyme disease can exhibit over 75 different possible symptoms and conditions – from flu-like symptoms, joint pains, and headaches, to heart palpitations, abdominal pain and much more.


For a more complete list of common misdiagnoses and potential symptoms of chronic Lyme disease please refer to the Common Misdiagnoses page at (source: CanLyme), and the Horowitz Lyme-MSIDS Questionnaire (source: Lyme Ontario).


How can you prevent Lyme and other tick-related diseases?

(Source: Canadian Lyme Disease Association)

The best way to prevent infection is to avoid tick-infested areas whenever possible, particularly in spring and early summer when nymph ticks feed. Adult ticks are a bigger threat in fall. Ticks favour moist, shaded environments; especially leafy wooded areas and overgrown grassy habitats.

Make your home and property tick safe. Indoor/outdoor pets will carry ticks into your home. Bird feeders will attract birds who are carrying ticks onto your property so do not have bird feeders or bird houses on your property.

Top tick habitat precautions:

  • Wear long pants and long-sleeved shirts. Tuck your pants into your socks to prevent ticks from getting inside your pants.
  • Check your clothes for ticks often. Ticks will climb upwards until they find an area of exposed skin.
  • Wear light coloured clothing to make it easier to spot ticks.
  • Walk on pathways or trails when possible staying in the middle. Avoid low-lying brush or long grass.
  • Apply insect repellent to your skin and clothing, especially at the openings such as ankle, wrist and neck.
  • Do tick checks on your clothes and skin when outdoors. Tiny ticks can be hard to get off clothes so using the sticky side of duct tape will help pull those nasty creatures off.
  • If you or your children have been outside playing, enjoying nature, or working, remove any visible ticks off your clothes and then put your clothes immediately into the clothes dryer first, then wash them.


Other Tick-Borne Pathogens

Beyond Lyme disease, ticks can transmit a number of other serious diseases. Recent studies have shown that a single tick can play host to up to 230 different species of pathogens. Though not all of these pathogens are associated with human disease, those that are, are capable of causing severe and debilitating illnesses in affected individuals. Many of these pathogens can be transmitted alongside B. burgdorferi, causing complex multi-pathogen disease states, whereas others are more likely to be acquired singly. Some of the most relevant pathogens (excluding B. burgdorferi) found in Canadian tick-species are:


– Babesia spp. – A genus of protozoan organisms similar to those that cause malaria. These organisms infect red blood cells, causing symptoms such as fevers, night sweats, chills, headaches, muscle pains, joint pains, ringing in the ears, decreased cognition, and gastrointestinal disturbances. Babesia is most often transmitted from Ixodes species ticks.


C Bartonella spp. – A genus of gram-negative bacteria responsible for several well-known illnesses such as cat-scratch disease and trench fever. These bacteria often invade the lining of blood vessels, causing symptoms such as fatigue, headaches, neck stiffness, poor appetite, swollen glands, and pains in the soles of feet. Bartonellosis may be characterized by an atypical, streaked rash resembling stretch marks, and is most frequently transmitted from Ixodes species ticks.


– Relapsing Fever Species of Borrelia – Members of the Borrelia genus of bacteria that are similar to those that cause Lyme disease. However, these bacteria are associated with tick-borne relapsing fever as opposed to Lyme disease. Symptoms of tick-borne relapsing fever include headaches, neck stiffness, joint pain, myalgia, nosebleeds, and cognitive impairment. Except for Borrelia miyamotoi, which is most commonly transmitted through the bite of Ixodes species ticks, the tick-borne relapsing fever organisms are generally transmitted through the bites of soft-bodied ticks (Argasidae).


– Rickettsia spp. – A genus of gram-negative bacteria responsible for causing spotted fever illnesses such as Rocky Mountain spotted fever (RMSF). These bacteria are obligate intra-cellular parasites, which take up residence in the cells lining blood vessels. Spotted fever infections generally causes non-specific symptoms such as fever, chills, headaches, muscles aches, nausea and neurological changes such as confusion and impaired cognition. RMSF is most commonly transmitted by dog ticks (Dermacentor variabilis).


– Anaplasma phagocytophilum – A gram-negative bacteria responsible for causing human granulocytic anaplasmosis. Symptoms of anaplasmosis in humans often include fever, headaches, muscle pain, chills, abdominal pain, cough, general malaise and confusion. Anaplasmosis is most commonly transmitted by Ixodes species ticks.


– Ehrlichia spp. – A genus of gram-negative bacteria responsible for causing ehrlichiosis. These bacteria are obligate intra-cellular parasites that infect white blood cells. Symptoms of ehrlichiosis are similar to that of human granulocytic anaplasmosis, and may include fever, headaches, chills, muscle pain, nausea, diarrhea, confusion, general malaise and conjunctival infection. Erlichiosis is most commonly transmitted by the lone star tick (A. americanum).


For more information on Lyme disease or other tick-borne diseases, please check out our Resources section.