Lyme disease is an illness spread through the bite of a blacklegged tick, also known as a deer tick, that is infected with the Borrelia burgdorferi bacteria. Not all ticks are infected with the bacteria, so not all tick bites spread Lyme disease. Lyme disease does not spread from person to person.
Early symptoms of Lyme disease usually occur within one to two weeks, but can occur as soon as three days, or as long as a month after a tick bite.
Initial symptoms differ from person to person, which makes Lyme disease very difficult to diagnose. Some people may have no symptoms at all. Others may suffer severe symptoms, but not for weeks after the bite and may not associate the illness with the bite. The sooner you get treatment, the sooner you can begin recovery.
Signs of Lyme disease can include one or a combination of the following symptoms with varying degrees of severity:
- Fever or chills
- Spasms, or weakness
- Numbness or tingling
- Swollen lymph nodes
- Skin rash
- Cognitive dysfunction (brain fog) or dizziness
- Nervous system disorders
- Arthritis/arthritic symptoms (muscle and joint pain)
- Abnormal heartbeat
If left untreated, symptoms can last for months or years and may include recurring arthritis (muscle and joint pain), nervous system and/or neurological problems, numbness and/or paralysis.
Source: Public Health Agency of Canada
What to do if you become ill
See your health care provider right away if you develop symptoms of Lyme disease in the weeks after a tick bite.
Lyme disease Information for Health Care Providers
- Be sure to take precautions when outside, especially in areas where blacklegged ticks are commonly found
- Use insect repellent containing DEET or icaridin when outside and apply it according to the manufacturer’s instructions
- Cover up exposed skin when you go outside by wearing long-sleeved shirts or jackets, long pants and socks
- Search your body for ticks after spending time outdoors
- Remove attached ticks from your body as soon as possible
- Pay special attention to the following body areas:
- Underarm areas
- It is also important to check your pets regularly for ticks. Although they cannot spread Lyme disease, dogs and cats can bring infected ticks into your home
- Permethrin-treated clothing may provide protection against ticks and mosquitoes
Removing a Tick
To remove the tick:
- Grasp the tick with a set of tweezers as close to the skin as possible
- Slowly pull the tick straight out until it is removed
- Do not squeeze the tick
- Do not put anything on the tick or try to burn it off
- After removing the tick, thoroughly cleanse the bite site with rubbing alcohol and/or soap and water
- Visit www.etick.ca for free tick identification
- Consult with your physician if the tick has been attached for more than 24 hours or you are feeling unwell in the weeks following a tick bite or being in a natural area
The purpose of tick identification and testing is to gather data and monitor for new and emerging tick populations in Ontario. All of York Region is now considered an estimated Lyme disease risk area. Tick submissions and tick dragging is no longer required for surveillance.
Residents bitten by a tick are encouraged to see their health care provider if they have concerns or experience symptoms. Please speak to your veterinarian if you find a tick on your pet.
Free online tick identification services
For your convenience, we encourage you to visit www.etick.ca to submit a picture of a tick for free identification. Ticks removed from both animals and humans can be submitted to see if it is a blacklegged tick, the species that can carry the Lyme disease bacteria.
Please note this service is for identification of the tick only. For concerns about Lyme disease transmission, please contact your health care provider.
Where are blacklegged ticks found in Ontario?
The risk for exposure is highest in regions where ticks infected with the bacteria that cause Lyme disease are known to be established. This includes areas along the north shores of Lake Erie, Lake Ontario and the St. Lawrence River. Surveillance efforts have identified blacklegged ticks throughout York Region and much of the Greater Toronto Area. Some of those ticks have tested positive for the bacteria that causes Lyme disease.
Blacklegged ticks can be transported by birds or other wildlife across regions. There is a chance of being exposed to Lyme disease through contact with infected ticks almost anywhere in Ontario. Take precautions against ticks when visiting any woodland habitats where ticks may be present.
Public Health Ontario Lyme Disease Map
All of York Region is now considered an estimated Lyme Disease Risk Area.
Updated on a yearly basis, the map of estimated Lyme disease risk areas has been developed to assist clinicians in the diagnosis and/or treatment of Lyme disease, with potential exposures or tick bites in the risk areas delineated on the map leading to greater concern about the risks of Lyme disease. Risk areas are represented on the map based on tick dragging.
- Public Health Ontario: Lyme disease information for residents, physicians and health units
- Ontario Ministry of Health and Long-Term Care: Lyme disease for Health Care Providers
- Health Canada: Safety tips, maps and statistics related to Lyme disease
- Lyme Disease and Other Tick-borne Diseases
- US Centres for Disease Control: Repellents and helpful tips on protecting yourself from tick bites
- The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines by the Infectious Diseases Society of America
- Tick Encounter Resource Centre: Information on tick identification