An Ixodes pacificus Cooley & Kohls (female) is shown in a handout photo. Across the country, tick populations are growing - and with them, tick-borne diseases like Lyme. But an advocacy group and the country's federal health office disagree on basic health practices. THE CANADIAN PRESS/ho-E. H. Strickland Entomological Museum - University of Alberta
August 07, 2013 - 1:07 PM
TORONTO - In the summer of 1991, Jim Wilson was in the process of leaving a home behind, moving from Nova Scotia to British Columbia. Unbeknownst to Wilson, he was also embarking on an odyssey that would leave him sick and weakened for years.
"I was cleaning out the yard, and I must have gotten something in my navel, because I had an eight-inch bull's-eye rash around my navel," says Wilson, now 59. "It stayed for about three weeks, and then it faded away."
A month after the bite, Wilson found that his legs became numb and tingling, and he needed sleep every few hours. By Christmas, he was constantly nauseous, struggled to get out of bed, and had developed neurological problems as well as issues with his nerves, eyes, joints and hearing and lymph nodes. Drug cocktails and a battery of tests from a vast array of medical specialists could not identify the problem.
But that first rash — and the flu-like symptoms that followed — are some of the telltale signs of a bite from a tick, a blood-sucking insect that can be as small as a seed but whose population is expanding rapidly in new areas in Canada — and bringing with it the growth of tick-borne diseases like Lyme.
"We have seen significant range expansion in one of the types of ticks that transmits Lyme disease," says Dr. Robbin Lindsay, a senior research scientist with the Public Health Agency of Canada.
When Lindsay first began studying ticks in the early '90s, the population was mostly localized in Long Point, Ont. In the two decades since, Western black-legged ticks have gathered steam in B.C., and one type in particular — the black-legged tick, which can transmit as many as five disease-causing agents including the bacterium that causes Lyme — now has populations stretching from Alberta to Newfoundland.
"We now have (five) populations in Nova Scotia, a couple in New Brunswick, a fairly extensive population in southwestern Quebec, a number in Manitoba, and elsewhere in Ontario, primarily in eastern Ontario," Lindsay says.
"In Atlantic Canada, those populations are fairly discrete and localized in one area, but in Ontario and Manitoba, they appear to be developing over a broad geographic area — it's like a front of ticks.... In some cases, they're simply spilling across the border."
Lyme isn't the only concern that ticks bring. Anaplasmosis is the second-most prevalent, which shares similar flu-like symptoms and can be fatal. Recently, ticks have developed the ability to carry borrelia miyamotoi bacteria, as well; it also causes Lyme-like illness.
But Lyme remains the most common. National Lyme data weren't collected until 2009, and the numbers for 2012 and 2013 have yet to be compiled. Lindsay says, however, that human cases of Lyme nearly doubled between 2009 and 2011, from 144 to 258.
Lindsay says birds have been migrating through the northeastern U.S., where more established populations of ticks have developed. That, plus global warming, has given ticks new areas to take root in Canada.
About 10 to 15 per cent of ticks, which hitch rides on birds or other animals, are infected when they first arrive. But that number can rise as high as 50 per cent as a population becomes more established.
"We've been (monitoring) for over 20 years, and the patterns of ticks are completely different from when we first started. The ticks are really moving," Lindsay says.
Awareness in wooded habitats — "You're not going to get them in a Walmart parking lot" — should be able to prevent infection, he says, suggesting light-coloured clothes that cover up your skin, including long pants, tucked into socks if possible.
DEET-based repellents are able to avert ticks in addition to mosquitoes and black flies, but Lindsay adds they need to be reapplied more frequently than labels suggest as ticks are larger and stronger than those other insects.
Upon returning home, a thorough visual check of your body is the best way to prevent infection. Lindsay suggests taking a shower not just because ticks can be washed off, but because it puts people in a situation where they are naked in front of a mirror.
He also recommends laundering your clothing, ideally using the dryer first. "They can actually survive through the washer, but the dryer, not so much."
He adds that not all bites result in the telltale expanding bull's-eye rash, and that any tick found on the body should be removed carefully — preferably with tweezers, pulling as closely as possible to the skin without rotating or crushing the insect. The location should be noted, in case further medical treatment is needed.
The bacteria are located in an infected tick's belly, so in most instances it takes up to 36 hours for the bacteria to reach the salivary gland and transfer into the body.
Lindsay says that while the news can be alarming, awareness will go a long way. He compared it to West Nile virus when it first arrived in Canada: "We took precautions to avoid mosquito bites before, now we have to take different kinds of precautions."
But he did acknowledge that this would be the new reality.
"Right now, infection prevalence in the ticks is still lagging behind. Sadly, that is going to come," says Lindsay. "Undoubtedly, as these populations expand, as the infection prevalence goes up, we're going to see an increase in the number of human cases."
News from © The Canadian Press, 2013