source: https://extension.umaine.edu/ipm/tickid/maine-tick-species/deer-tick-or-black-legged-tick/
Last night, I attended a meeting of Nature PEI that left me
itchy and scratchy. The topic was
black-legged or deer ticks, the kind that can transmit lyme disease to the
animal (including people) it bites. Lyme disease is a debilitating disease
which starts with flu-like symptoms and then progresses to facial paralysis and
very sore joints that mimics arthritis.
It is very hard to diagnose, but if it is caught early, a long course of
antibiotics can stop the disease.
Lyme disease is caused by a type of bacteria that lives in
the gut of ticks. Ticks need a blood
meal to move on to the next stage of their life cycle and before they can
produce viable eggs. When they bite an
animal or a person, they insert their mouth parts deep into the skin, and end
up with their posterior up in the air. First they inject an anesthetic, so that
the host never feels the tick bite.
Ticks are just after the protein in blood, which they are able to
separate from the rest of the blood and inject back into the victim. As they inject the fluid back in, what also
comes along for the ride is a type of bacteria called borrelia. The
bacteria is shaped like a corkscrew. When
it is injected into the bloodstream, it looks for nerve or muscle tissue.
It corkscrews into that tissue and begins to multiply.
Cases of lyme disease are on the rise. It is common in the northern US, and is becoming
more prevalent along the southern border with Canada. Nova Scotia is particularly hard hit along
the coast. We on PEI think we are immune
because we live on an island and we have no deer, but there have been many
confirmed cases here.
"The risk of Lyme disease is rapidly increasing in Canada as the climate changes and tick populations expand," says Kami Harris, PhD candidate at the Atlantic Veterinary College in Charlottetown. "Due to the many waterways in our region, which are favourite haunts of tick-carrying birds, the Maritimes have an increasing density of ticks."
Ticks hitch a ride on migrating birds. They are also very fond of mice and meadow
voles. After a blood meal, they drop off and live in leaf litter.
We are most likely to catch lyme in May or
October-November.
Ticks can be as small as a fleck of pepper. When they catch hold of a person, they will
crawl up their leg looking for a place that is dark, warm and moist (think
armpits and genitals). Most often, a
person is not aware they were bitten. In
only 8 percent of cases, a tell-tale bulls-eye shaped rash appears at the site
of the bite.
Black-legged ticks don’t seem to like cats – they bite them,
but soon drop off. But dogs are a very
much at risk. Dogs will quickly react to
the bite by becoming lethargic, refusing to eat or drink, becoming lame, and
losing weight. There is a test called
the “snap test” that is an indicator that a dog may have contracted lyme
disease. But it takes at least two weeks
from the time of the bite before the antibodies show up in the test. Antibiotics, when administered promptly, will
cure the disease.
With people, unfortunately, the story is not as
positive. Doctors have very little
knowledge of lyme disease, because they don’t realize it is prevalent here. In people, the disease can have no symptoms
at all, or someone can suddenly come down with arthritis-like symptoms or
facial paralysis. If the course of antibiotics
is not started promptly, there is no cure.
There is also a risk of misdiagnosis because the blood test for lyme disease used on people looks for just one type
of bacteria, and will miss the other types which also cause the disease.
A few doctors in Massachusetts
and Maine are experts in this field.
Many Canadians who have not been able to get help in Canada have
resorted to getting treatment in the US.
At the Nature PEI meeting, an audience member spoke about their grand-daughter, who
was a very fit athlete who did a lot of cross-country running. Now she is on crutches, and is so weak she
can hardly feed herself.
Prevention
Lime disease can be transmitted from one person to another
through sexual contact.
When out in the woods, try to stay on bare pathways away
from tall grass. Don’t handle leaf
litter without gloves, because that’s where ticks live.
When walking in the woods or in tall grass, wear
long sleeved shirts and long pants. Tuck
your pant hem into your socks. Wear
white socks and light-coloured clothing, so that you will be able to see the
tiny black ticks. If you find one
embedded in your skin DO NOT burn it off.
This may leave the mouthparts behind, which can cause a nasty
infection.
Instead, use tweezers to get as close to the skin as possible,
gently squeeze and then pull straight up.
The skin will be pulled up too, because the tick hangs on tight, but
eventually it will let go. Try to keep
hold of it and place directly into a plastic baggie or jar.
Take it to your nearest veterinarian, who will send it to
the lab at Mount Allison University for testing.
The more we know about this critter, the better we can deal
with it.