In the early 1970s a group of children and adults in Lyme, Connecticut, and the surrounding areas were suffering from puzzling and debilitating health issues. Their symptoms included swollen knees, paralysis, skin rashes, headaches, and severe chronic fatigue. By the mid-70s, researchers began describing the signs and symptoms of this new disease and name it Lyme disease. In 1981, a scientist Willy Burgdorfer, found the connection between the deer tick and the disease. He discovered that a bacterium called a spirochete (Borrelia burgdorferi), carried by ticks, was causing the disease.
Geography and Travel
Lyme disease is spread through the bite of infected ticks. There are two types of ticks that can spread Lyme disease in Canada, the blacklegged (or deer tick, Ixodes scapularis) in southeastern and south-central regions of Canada western and the blacklegged tick (Ixodes pacificus) in British Columbia.
Source: Public Health Agency of Canada
Ticks become infected with Lyme disease bacteria by feeding on infected wild animals, such as birds and rodents. Once infected, ticks can spread the bacteria to humans and pets. In most cases, the infected tick must attach and feed for at least 24 hours before the bacteria can be transmitted.
Most humans are infected through the bite of immature ticks (called nymphs) that are approximately the size of a poppy seed. Adult ticks (approximately the size of a sesame seed) can also spread Lyme disease.
In Canada, Lyme disease can be found in the following provinces:
Lyme disease cases reported between 2009 and 2017:
- 2009: 144 cases
- 2010: 143 cases
- 2011: 266 cases
- 2012: 338 cases
- 2013: 682 cases
- 2014: 522 cases
- 2015: 917 cases
- 2016: 992 cases
- 2017: 2 025 cases
- 2018: 1 487 cases
- 2019 : 2 636 (preliminary)
*The 2016 and 2019 Lyme disease cases are reported based on the recently updated Lyme disease case definition.
Early symptoms include a small, red bump that appears at the site of a tick bite or tick removal and resolves over a few days. This is normal after a tick bite and does not indicate Lyme disease.
However, these signs and symptoms may occur within a month after infection:
Rash. From 3 to 30 days after an infected tick bite, an expanding red area might appear that sometimes clears in the center, forming a bull's-eye pattern. The rash (erythema migrans) expands slowly over days and can spread to 12 inches (30 centimeters) across. It is typically not itchy or painful.
- Flu-like symptoms. Fever, chills, fatigue, body aches and a headache may accompany the rash.
If untreated, new signs and symptoms of Lyme infection might appear in the following weeks to months. These include erytyema mirgrans, joint paint, nausea and vomiting, diffuse rash and neurological problems. Several weeks after infection, some people develop heart problems, eye inflammation, liver inflammation (hepatitis) and severe fatigue.
- Wear light coloured clothing to help spot ticks
- Use insect repellents that contain DEET or Icaridin. Always follow the manufacturers instructions.
- Do daily full body checks on yourself, your children and pets after coming in from the outdoors
- Cut your grass and dispose of leaf litter where ticks can live.
- Outdoor workers should shower or bathe within two hours of being in forested or long grass areas
For mor information on Lyme disease:
- PHAC Information on Lyme Disease
- PHAC Poster -Top Ten Tick Hiding Spots
- Lyme Disease Surveillance in Canada
- PHAC Information for Health Professionals
- PHAC Lyme Disease Awareness Resources
- National Microbiology Laboratory Research on Lyme Disease
- AMMI Canada Position Statement on the Diagnosis and Treatment of People with Persistent Symptoms That Have Been Attributed to Lyme Disease
- AMMI Canada -Facts About Lyme Disease
- CDC Information on Lyme Disease
- Tick Encounter -University of Rhode Island
- Public Health Ontario -Lyme disease human surveillance in Ontario: A systematic review
- Public Health Ontario Lyme Disease Information
- Ontario Lyme Disease Risk Areas Map 2021
- Provincial Resources: