Lyme disease: Tiny tick, big problem
What is Lyme disease, how is it diagnosed and treated?
So the weather's ideal and you're raring to enjoy the great outdoors — but you're feeling fatigued, and you're suffering from chills, fever, headache, muscle and joint pain. Maybe swollen lymph nodes, too.
Can't figure out why you're coming down with conditions you'd expect to feel in the winter?
Could be you're in the early stages of Lyme disease — a condition first identified in the mid-1970s. The disease was named after the town where the first cases were diagnosed — Lyme, Conn. The illness is caused by the bite of two species of ticks — blacklegged ticks (sometimes called deer ticks) and western blacklegged ticks.
Lyme disease was unknown in Canada up until the 1980s. Initially, it was identified only at Long Point and Point Pelee, Ont. — which is the farthest south you can get in Canada.
Since then, Lyme disease has become established from Nova Scotia to B.C., except for Alberta and Saskatchewan.
In January 2011, the National Microbiology Laboratory in Winnipeg discovered 24 people were wrongly told they didn't have Lyme disease when they in fact have the illness. The mistake was found during a quality control review at the lab.
If Lyme disease is not treated with antibiotics soon after infection, patients can suffer arthritis and neurologic problems.
In August 2008, the Canadian Lyme Disease Foundation, a patient advocacy group, said levels of Lyme disease are being underreported across the country — an assertion rejected by medical authorities including the Association of Medical Microbiology and Infectious Disease Canada. CanLyme called for improved diagnostic testing, saying annual infection rates ranged from 2,000 to 20,000.
Lyme disease has become the most common vector-borne illness in the United States. The U.S. Centers for Disease Control and Prevention says it receives reports of about 20,000 cases a year. But the agency estimates that that represents only about 10 per cent of the total.
Lyme disease became a nationally reportable disease in Canada in 2010. Doctors are now required to report all cases to the Public Health Agency of Canada through their provincial public health system.
Recent studies suggest that the incidence of Lyme disease in Canada is increasing, the federal agency said.
How do ticks pass on the disease?
They have three feeding stages: larvae, nymph and adult. When a young tick feeds on an infected animal, it picks up a bacterium called Borrelia burgdorferi. It's normally carried by mice, squirrels, birds and other small animals.
The bacterium then lives in the gut of the tick. If you are the tick's next meal after it's ingested infected blood, you could show symptoms in three to 30 days.
Most cases are reported in late spring and summer, when the young ticks are most active and people are outdoors more often. Ticks often feed on deer but don't infect them very often. Deer are important to the tick population because they provide them with a lot of food — and a mode of transportation over long distances, which is important in maintaining the tick population.
Health Canada estimates that about 10 per cent of blacklegged ticks in any infected area carry the bacterium that causes Lyme disease.
What are the symptoms of Lyme disease?
The first sign that you may be infected is a circular rash surrounding the spot where the tick bit you. It'll show up between three and 30 days after the tick helped itself to your blood. The rash may be followed by symptoms like fatigue, chills, fever, headache, muscle and joint pain and swollen lymph nodes.
If left untreated, the disease can progress to a second phase, which can last several months. Symptoms in the second phase include migraines, weakness, multiple skin rashes, painful or stiff joints, abnormal heartbeat and extreme fatigue.
Still not seeking treatment? Well, it's highly unlikely that you will die, but you may suffer symptoms such as chronic arthritis and neurological symptoms, including headaches, dizziness, numbness and paralysis. Is there a cure?
Lyme disease is generally easy to treat with antibiotics in its early stages. But if left too long, treatment may involve several rounds of antibiotics.
How do I protect myself?
Make yourself a difficult meal for a tick.
Nova Scotia zoologist Andrew Hebda notes that ticks aren't very active. They can't leap at you as you walk by. But if you brush up against them, they can latch on to you. Hebda recommends that you stay on trails and avoid deep bush.
Health Canada offers several tips, including:
- If infected ticks are in your area, wear long-sleeved shirts that fit tightly around the wrist, and long-legged pants tucked into socks or boots. Light-coloured clothing makes it easier to see if there are any ticks on your clothes.
- Wear shoes that cover your entire foot — avoid sandals in areas where ticks might be.
- Use insect repellents that contain DEET to repel ticks. Repellents can be applied to clothing as well as exposed skin.
How easy is it spot a tick?
Adult ticks are about two- to five-millimetres long and are not too difficult to spot. But in their nymph form, they are the size of a poppy seed. At this stage, the nymph requires a blood meal to reach adulthood.
"Basically look for freckles that move," Hebda said.
What should I do if I find a tick?
If the tick is embedded in your skin, Hebda says, using tweezers, carefully remove it without detaching its mouth. It's virtually impossible to identify species of ticks without the mouth part. Health Canada labs will not analyze ticks if they are missing the mouth.
"If you can't remove it," Hebda says, "see your family physician."
Do ticks tend to seek out specific areas of the body?
Blacklegged ticks need about 48 hours for a proper feeding. Hebda says they tend to seek out more secluded parts of your body, like "behind the knees and points further north."
Hebda adds, despite the risk, there's absolutely no reason you should avoid the woods or stay away from trails.
"When you come in, just wipe yourself off and take a gander, see if there's anything moving."
What other steps can I take to minimize the risk?
There are several steps you can take to make sure your yard does not become a haven for ticks that might be able to infect you with Lyme disease.
- Keep grass on your property well cut to reduce the amount of habitat suitable for ticks.
- Remove leaves and brush around your house and at the edges of lawns.
- Create a barrier of wood chips between lawns and wooded areas to restrict the migration of ticks. Ticks love cool, damp areas. They hate hot, dry places.
- Check your pets regularly for ticks.
- Keep the ground around bird feeders clean.
- Stack wood neatly and in dry areas.
- Keep playground equipment, decks and patios away from the edge of your yard and away from trees.
- Discourage deer: if they come on your property, don't feed them. Construct barriers to prevent them from coming on to your property.
Are there other illnesses that can be passed on by ticks?
Yes. Ticks can pass on more than just Lyme disease. These include:
- Human granulocytic anaplasmosis — a disease that is often difficult to diagnose because symptoms can be non-specific. Most people experience headaches, fever, chills, myalgia and an overall sensation of not feeling well.
- Human babesiosis — a malaria-like infection first identified in the U.S. on Nantucket Island in Massachusettes.
- Powassan encephalitis virus — a potentially deadly disease named for the Ontario town where it was first diagnosed. There have been as many as 27 cases across North America since 1958.
Tick-borne illnesses normally present themselves between June and September.