Updated July 5, 2017

Lyme disease in humans is caused by three species of Borrelia bacteria. In North America, Lyme disease is caused primarily by Borrelia burgdorferi, while in Europe the disease is caused mainly by B. garnii and B. afzelli. In Ontario, transmission occurs through the bite of infected blacklegged ticks called Ixodes Scapularis or deer ticks. The risk for exposure to the disease is highest in regions where the ticks that transmit Lyme disease bacteria are known to be established. Blacklegged ticks are found in Toronto with Morningside Park, Rouge Park and Algonquin Island Park being established areas of risk. However, the risk of acquiring Lyme disease in Toronto is believed to be low.

Lyme disease prophylaxis and diagnosis algorithm for clinicians