Lyme Disease
July 2012
Lyme disease is an illness caused by the bacteria Borrelia burgdoferi (B. burgdoferi). In the last five years an average of 20 people per year, infected with Lyme disease, were reported to Toronto Public Health. Almost all of these people acquired the disease outside the City of Toronto.
How do people get Lyme disease?To get Lyme disease, a person must be bitten by a black-legged tick (or deer tick) Ixodes scapularis that is infected with the B. burgdoferi bacteria. The tick needs to be attached to your body for greater than 24 hours in order for the tick to pass on the bacteria. The ticks are small (3-5mm) and people often do not realize that they have been bitten. Lyme disease is not spread from one person to another.
Where can I be exposed to an infected tick?In Ontario, the greatest risk areas for coming in contact with infected black-legged ticks are:
- Long Point Provincial Park
- Point Pelee National Park
- Prince Edward Point National Wildlife Area
- St. Lawrence National Park
- Rondeau Provincial Park
- Turkey Point Provincial Park
- Wainfleet Bog Conservation Area
The black-legged tick also feeds on birds and other animals which can carry the ticks to other areas in the province. Therefore it is possible to be infected with Lyme disease anywhere in Ontario. Manitoba, Quebec, New Brunswick and Nova Scotia all have populations of blacklegged ticks.
In the U.S., tick populations mainly occur in the midwest and northeastern regions. The western blacklegged tick (Ixodes pacificus) lives along the Pacific Coast and is the main vector of Lyme disease in British Columbia.
What are the symptoms of Lyme disease?
Symptoms usually begin 3 days to 4 weeks after a bite, and include:
- Fever and chills
- Headache
- Muscle and joint pains
- Fatigue
- Stiff neck
- Circular rash (also known as a bull's eye rash). This rash occurs in 70 to 80% of people who get Lyme disease.
When there is no rash it can be difficult to diagnose Lyme disease as the symptoms mimic many other illnesses. If left untreated, Lyme disease can lead to further disease with symptoms including migraines, weakness, multiple skin rashes, painful or stiff joints, cardiac abnormalities and extreme fatigue. If the illness continues untreated it can affect the central nervous system, brain or heart.
How do I know if I have Lyme disease?The doctor will perform a clinical assessment and take a detailed history of possible tick exposure. Blood work can also be done to test for Lyme disease but should not be the sole factor in determining if someone has the disease.
Is there treatment for Lyme disease?Yes, there are antibiotics available for treatment if your doctor diagnoses Lyme disease.
How do I remove a tick and what do I do with it?If you find a tick on yourself, remove it with fine-tipped tweezers. Do not squeeze or try to burn it off. Grab the tick as close to your skin as possible. Pull the tick away from your skin gently but firmly. Place the tick in a jar or bottle and take it to your health care provider or call Toronto Public Health.
Ticks that are sent to Toronto Public Health can be tested to determine that the tick is the black-legged tick and can be further tested to see if the tick carries the B. burgdoferi bacteria.
Can Lyme disease be prevented?There is no vaccine available in Canada to prevent Lyme disease. However,there are many things you can do to prevent being bitten by a tick:
- Wear light coloured clothing so you can easily spot ticks.
- Wear long sleeves and long pants; tuck your pants into your socks.
- Avoid shrubs or grassy areas (ticks are usually found low to the ground).
- Use bug repellent containing DEET. Please follow manufacturer's instructions.
- Perform a daily careful self-inspection for attached ticks, especially after being in tick-infested areas. Do not forget to check children and pets.
For more information about Lyme disease call Toronto Public Health at 416-338-7600, TTY 416-392-0658.
Related LinksLast updated July 2012
