Scientist urges precaution, not panic, to combat Lyme disease

Posted By MICHAEL JIGGINS, SUN MEDIA

Posted Aug. 1st, 2009 at the Kingston Whig

It's a recipe for panic.

Media reports about creatures that crawl onto your skin unknowingly and start sucking your blood, injecting you with a bacteria that causes a potentially life-threatening disease in the process.

And these tiny vampires are all around us after slipping across the Canada/U. S. border.

In a presentation this week to Rotary Club of Brockville members, St. Lawrence Islands National Park ecosystem scientist Emily Gonzales used education to battle what she said is unwarranted panic over black legged ticks and the Lyme disease they spread.

"The incidence of Lyme disease is still very low in this region and it's still very treatable," Gonzales said in an interview after her 25-minute presentation at the Brockville Country Club.

"There's lots of ways you can get to it before it gets to you."

While it's wise to be concerned enough to take precautions, Gonzales assured the noon-hour crowd of about 40 there's no need to hide indoors.

"As long as folks are informed, we're all still going to be able to enjoy our beautiful landscape," said Gonzales.

Blacklegged ticks (commonly known as deer ticks) have been steadily infiltrating this part of Ontario from the United States in recent years.

As part of her job at St. Lawrence Islands National Park where employees and visitors are what is essentially the front-lines of the tick invasion, Gonzales is heading up a study to determine the extent the ticks have become a part of the landscape.

"We feel we need to know more information. Right now we have no idea what our incidence of Lyme disease is," she said.

To do that, the study is doing live trapping of small rodents like mice, squirrels and shrews at 12 sites throughout the park.

Methods such as drag sampling can confirm the presence of ticks in an area, but Gonzales said only by testing the blood of captured rodents can the prevalence of Lyme disease measured.

Studies to date have shown that the ticks are definitely present throughout the Thousand Islands region, however, Gonzales described their population as "spotty."

For instance, she noted none have been found this year at the park's headquarters and visitors' centre at Mallorytown Landing.

The largest concentration is on islands near the U. S. with large deer populations.

"And that makes sense," said Gonzales in an interview. "It's moving like a wave from the U. S. to us."

In her presentation, she stressed blacklegged ticks don't inherently have the bacteria that causes Lyme disease.

Instead, they pick it up when they feed on a host carrying the disease, often a white-footed mouse or birds nesting on the ground.

Although the ticks are present year round, Gonzales said it's during the nymph stage of their life cycle (usually April through June) when they present the greatest danger of transmitting Lyme disease.

Nymph ticks are about the size of a poppy seed and Gonzales said it's critical for people spending any time in a tick habitat to carefully and regularly check if one has become attached.

She noted in response to an audience question that ticks won't wash off in the shower once they've attached their mouth parts to a person's skin.

"If you find that nymph within 24 to 36 hours before it has fed, before it's engorged, and get it out, your chance of getting Lyme disease is extremely small," she said.

Contrary to popular belief, Gonzales noted ticks don't fly or jump onto you.

Instead, they wait for you to brush up against them in tall grasses, brush, shrubs or while strolling through leaf litter.

It can take up to a week for the tick to finish feeding, at which point it falls off.

Studies indicate anywhere from six to 12% of black legged ticks carry the Lyme disease causing bacteria, said Gonzales, who noted no other species of tick carries the disease.

Gonzales said there are several simple precautions to take -- steps she stressed will have to become second nature as they are in the northeastern U. S. where Lyme disease is most prevalent.

These include:

* Wearing a light-coloured long-sleeved shirt, hat and pants with the bottoms rolled into your socks.

* Walk in the middle of trails away from tall grass and bushes where ticks live.

* Spray a bug repellent with DEET on your clothing.

In addition to checking yourself for ticks, pets should also be examined closely as they can pass them onto humans.

As for tick removal, Gonzales warned against such methods as using a lit match or squeezing the insect, which she said can actually cause the tick to regurgitate into the host and increase the potential to transmit bacteria.

Instead, she recommended purchasing a tick remover or tweezers and carefully sliding them under the tick and prying the mouth parts away from your skin.

Although the park's study is still in its infancy, Gonzales said she's actually found herself becoming "fascinated" by the blacklegged tick.

Even if she admits to feeling as squeamish as some of those Rotarians scratching at phantom ticks after her presentation.

"Doing this project has been so reassuring, because really I feel I'm not going to get Lyme disease. I know what to do, I know how to keep myself safe and keep those safe around me," said Gonzales.