WHAT IS IT?
Lyme disease is a tick-transmitted disease of people and animals that is caused by a microscopic bacteria called Borrelia burgdoferi. In nature, Lyme disease is most often associated with small mammals such as white-footed mice, deer mice and birds or with large animals such as deer. In people, the symptoms of this illness vary greatly. As a result, this disease has been called " the great imitator" resulting in patients suffering from this illness being misdiagnosed. The infection often starts out as a skin rash with or without flu-like symptoms, and can progress to arthritic, cardiac or neurologic disease.
Diagram courtesy of the Center for Disease Control
HOW DO TICKS TRANSMIT LYME DISEASE?
Blacklegged ticks are the only type of tick in Ontario that can consistently transmit Lyme disease. Blacklegged ticks can be no bigger than a pin head and since its bite is painless many victims of Lyme disease are unaware they have ever been bitten. Even with a bite from an infected blacklegged tick, there is only a small chance of getting Lyme disease. Ticks feed on blood by inserting their mouthparts (not their whole bodies) into the skin of a person, or an animal. Ticks feed slowly and their body gradually enlarges as it feeds, making it more visible. It usually takes from 3 to 7 days for a blacklegged tick to take a complete blood meal.
Picture courtesy of the Public Health Agency of Canada
Ticks are most likely to transmit infection after being attached for more than 24 hours of feeding (see figure below) because the bacteria requires time to migrate from the tick's gut to its salivary glands. Because of this delay, prompt detection and removal of ticks is one of the key methods of preventing Lyme disease.
Diagram courtesy of the Public Health Agency of Canada
If a blacklegged tick has Lyme disease and it is removed quickly from the body, it is very unlikely that it has transferred Lyme disease to the human host. People who are bitten by a tick and who develop symptoms of infection should see their doctor.
Portions of this section have been adapted from the Public Health Agency of Canada
WHERE IS LYME DISEASE FOUND IN ONTARIO?
Ticks can be found on tall grass and brush in wooded areas.In Ontario, blacklegged ticks are more commonly found in areas along the north shores of Lake Erie, Lake Ontario, and the St. Lawrence River. Locations with established blacklegged tick populations infected with the Lyme disease agent, include: Long Point Provincial Park, Turkey Point Provincial Park, Rondeau Provincial Park, Point Pelee National Park, Prince Edward Point National Wildlife Area, Wainfleet Bog Conservation Area, and in the St. Lawrence Islands National Park area. The precise boundaries of these established tick populations are difficult to define but it is anticipated that some of these populations will continue to expand into neighboring areas.
Blacklegged ticks are also known to feed on migrating birds and as a result, they can be transported throughout the province. Therefore, while the potential is low, it is possible for people to encounter blacklegged ticks, or to be infected with Lyme disease from the bite of an infected blacklegged tick almost anywhere in the province. In general, blacklegged ticks infected with Lyme disease are much more common in the United States along the Atlantic seaboard from Maine to Virginia and in Minnesota and Wisconsin than they are in Ontario .
Portions of this section have been adapted from Ontario Ministry of Health and Long Term Care
WHAT ARE THE SYMPTOMS?
The most common symptom of Lyme disease is a skin rash that occurs at the location of the tick bite within 2 to 30 days. Within days to weeks following a tick bite, 80% of infected people will have a red, slowly expanding "bull's-eye" rash (erythema migrans) around or near the site of the bite. If left untreated the rash will disappear within 3 weeks.
Picture courtesy of the Center for Disease Control
Flu-like symptoms may also occur at the stage of the disease. These include headache, chills, pains in the joints, loss of appetite, nausea, fatigue, fever, aching muscles, stiff neck, sore throat and vomiting. If left untreated these symptoms will also disappear within 10 days.
The later stages of Lyme disease can involve arthritic, cardiac and neurological complications. These can occur weeks, months or even years after the initial symptoms have disappeared.
WHAT IS THE TREATMENT FOR LYME DISEASE?
Antibiotic treatment is generally effective in the early stages of the disease. In most circumstances, treating people who only have a tick bite is not recommended. Individuals who are bitten by a deer tick should remove the tick and have the tick tested. If possible save the tick and submit it to Oxford County Public Health. A Public Health Inspector will submit it to the Public Health Laboratory for analysis. Medical attention should be sought if any symptoms of early Lyme disease develop over the next month. Signs of infection or positive blood tests are needed before beginning treatment. It is possible to get re-infected after being treated for Lyme disease.