Lyme Disease

What is Lyme disease?

• context Lyme disease is an illness caused by bacteria called Borrelia burgdorferi. This bacterium is carried by certain ticks and spreads to the host when the tick bites. The bacterium is normally found in small animals, such as mice, squirrels, chipmunks, shrews, etc.
• context Lyme disease in humans can have a range of effects from rashes and flu-like symptoms to more serious symptoms, including arthritic, cardiac, and neurological effects. It can often be effectively treated, especially if detected in the early stages.
• context Lyme disease is an occupational concern for people who work outdoors. Any person who spends time outdoors is also at risk.
• context In Canada, Lyme disease is the most frequently reported "vector-borne" disease. A vector is the term for any insect or arthropod that carries and transmits a disease pathogen (virus, bacteria, etc.).

How is Lyme disease transmitted?

Ticks can become infected with Borrelia burgdorferi by feeding on infected wild animals, and then can spread the bacteria through their saliva when they feed on blood from the host. Ticks cannot fly - they wait for an animal or person to pass near them, and when the animal or person makes contact, the ticks attach themselves to the skin to feed. Ticks are typically found: In North America, Lyme disease is transmitted (spread) mainly by two species of ticks: The Public Health Agency of Canada (PHAC) states that there is no evidence that Lyme disease can spread from person-to-person. Pets, especially dogs, can get Lyme disease, but there is no evidence that pets can spread the infection directly to humans. They may, however, carry infected ticks into the home or yard, which may increase the chance of transmission.

• context In natural wooded areas
• context In areas with shrubs, leaf litter, wood piles, or tall grass
• context Near animals that ticks feed on, such as rodents, birds, and deer
• context In temperatures at 4°C and higher
• context Blacklegged tick (sometimes called the deer tick), Ixodes scapularis
• context Western blacklegged tick, Ixodes pacificus

What are the signs and symptoms of Lyme disease?

Tick bites are usually painless, and most people do not know they have been bitten. Signs and symptoms of Lyme disease vary greatly from person to person, and may appear anywhere between 3 to 30 days after a person has been bitten. Symptoms often include: One sign of infection can be an expanding rash, sometimes referred to as a "bull's eye" rash because it may have rings spreading from the bite site (known as erythema migrans (EM rash)). It is important to note that rashes without the bull's eye may occur, and that rashes do not appear in every case of Lyme disease infection. Later symptoms of Lyme disease can appear days to months after a bite and include: If untreated, a condition called late disseminated Lyme disease may occur. PHAC reports symptoms include recurring arthritis (muscle and joint pain), nervous system and/or neurological problems. Symptoms can also include numbness and/or paralysis (inability to move parts of the body). Deaths from Lyme disease are rare but may occur. Lyme disease can be difficult to recognize, and it has been confused with other diseases. It is important for people to consult with their doctor if they feel it is possible that they have Lyme disease. PHAC provides more information on Lyme Disease.

• context Fatigue
• context Fever or chills
• context Headache
• context Muscle and joint pain
• context Swollen lymph nodes
• context Skin rash
• context Severe headaches
• context Additional EM skin rashes
• context Neurological disorders (dizziness, mental confusion or inability to think clearly, memory loss, inflammation of the brain and spinal cord, nerve pain, numbness or tingling in the hands or feet)
• context Nervous system disorders, including facial paralysis or Bell's palsy (loss of muscle tone or droop on one or both sides of the face)
• context Muscle, joint, tendon, and bone aches
• context Arthritis with severe joint pain and swelling, particularly the knees and, less commonly, in other joints, such as the ankle, elbow, and wrists

Can Lyme disease be treated?

• context In most cases, yes. Antibiotics can effectively treat Lyme disease, especially when treatment begins early. Cases that reach the later stages of the disease, however, can be difficult to treat, and some symptoms can persist.
• context PHAC reports that removing the tick within 24-36 hours usually prevents infection.

How do I know if I have a tick bite?

• context Many people who develop the disease do not remember seeing ticks or being bitten. Tick bites commonly occur from May to September in North America, although blacklegged ticks can be active most of the year. Ticks sometimes move around on the body, but they usually attach themselves to the skin and stay in one place. Before feeding, ticks look like small, brown scabs or freckles. After feeding, ticks may swell considerably and could be as big as a raisin or a small grape.
• context Follow the link for more information about blacklegged (deer) ticks (including photographs) from the Government of Canada.
• context If you think you have been bitten by a tick, or if you are showing symptoms, contact your employer and a healthcare professional. Your employer may also be required to notify the government department responsible for health and safety, or the workers' compensation board.

Are some locations more at risk than others?

Yes and no. There are areas in which the bacteria are endemic, meaning the disease is established and present more or less continually in that community. In Canada, blacklegged and western blacklegged tick populations have been confirmed or are growing in the following areas: However, it is important to note that ticks (including those infected with the Borrelia burgdorferi bacteria) can be spread by birds, particularly songbirds that feed on the forest floor. Because these birds are migratory, there is the potential for new populations of the bacteria to spread across the country. This fact means that you do not have to be in an endemic or high-risk area to be at risk of contracting ticks and the disease. Ticks are also spreading to new areas in Canada due to climate change. Climate change is increasing the number of ticks, the length of time ticks can survive, and the duration of the season.

• context Coastal and southern British Columbia
• context Southern Manitoba
• context Western, southern, and southwestern Ontario
• context Southern Quebec
• context Mid and Southern New Brunswick and Grand Manan Island
• context Nova Scotia

What tests are available for Lyme disease?

• context When a person becomes infected, the body creates antibodies to protect itself from the bacteria. Certain blood tests are available to measure these antibodies. However, sometimes a "false negative" test can result if there are not enough antibodies in the blood for the tests to detect accurately. A doctor should also do a complete medical examination and gather information about your recent outdoor activities in order to make a clinical diagnosis for Lyme disease.

Who is at risk?

Anyone who either works outside or has contact with animals that may carry ticks (including domestic animals like dogs, cats, goats, cows, horses, etc.) is susceptible to being bitten by a tick. Many occupations may be at risk, including: Similarly, any person who spends a lot of time outdoors (hiking, camping, birding, golfing, hunting, fishing, etc.), especially in grassy or wooded areas, may also be at risk.

• context Construction workers
• context Dog walkers
• context Forestry workers
• context Farm workers
• context Groundskeepers
• context Landscapers
• context Loggers
• context Telecommunications line workers
• context Veterinarians
• context Park or wildlife management

What can a workplace or home do to reduce the presence of ticks?

• context Keep the lawn and yard well-maintained to prevent ticks from living near the home or workplace.
• context Keep the grass mowed. Trim trees and shrubs.
• context Remove leaf litter, brush, and weeds at the edge of the lawn, and around stonewalls and woodpiles.
• context Clean up and seal stonewalls and small openings around the home to help discourage rodents.
• context Keep stacked firewood piles and bird feeders away from buildings.
• context Keep any pets, particularly dogs, out of the woods and talk to your veterinarian about tick repellents for your pets.
• context Move children's swing sets and sandboxes away from the woodland's edge and use a woodchip or mulch foundation.
• context Consider using hard landscape items, such as woodchips, mulch, stones, gravel, tile, or metals.
• context Create a border or barrier between the lawn, woods, or stonewalls to discourage deer and rodent activity.
• context Widen woodland trails.
• context Consider a least-toxic pesticide application as a targeted barrier treatment.