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January 31, 2003
GN tests for trichinosis
infection in walrus tongues
Repulse Bay animals
used in pilot project
MIRIAM
HILL
After a significant outbreak
of trichinosis in Repulse Bay, Nunavuts department of health is establishing
a program to test walrus meat for the parasite that causes the disease.
John Raven, an environmental
health officer based in Rankin Inlet, said after 16 people contracted the disease
in Repulse Bay in December, the department decided to use that community in
a pilot project.
Hunters will soon be able
to send the tongues of walrus they harvest to the lab in Rankin Inlet and find
out within 24 hours whether the meat is infected or safe to eat.
"The tongue has the
highest concentration of trichinosis," Raven explained. "A walrus
can have light infection, moderate, heavy, whatever, and if theres any
infection in a walrus it will appear in the tongue."
Raven said hunters from
other communities can also submit walrus tongues to be tested, but the department
is focusing its efforts on Repulse Bay this year.
Because of the outbreak
there, he said, people in the community are very sensitive to the seriousness
of the disease and want to stop any further spread. Raven will be travelling
to meet with residents in early February to explain the program.
Trichinosis, known in the
scientific community as trichinellosis, is a parasitic disease caused by the
larvae of the trichinella worm.
When infected, uncooked
meat of a carnivore, such as a polar bear, walrus or pig, is eaten, a number
of cysts are ingested with it. When these cysts get into the stomach, the acid
and enzymes break them down and they travel through the intestinal tract down
to the lower bowel. During that time they hatch into worms. The worms mate and
produce thousands of new worms. The number of worms determines how sick a person
will become.
Nausea, diarrhea, vomiting,
fatigue, fever and abdominal discomfort are the first symptoms of the infection,
showing up between one and two days after eating the meat. If its caught
when the parasite is still in the persons stomach it can be treated with
antibiotics, but if it has already migrated in cyst form to the muscles, its
too late and in severe cases can cause death.
The only way to ensure
the parasite is rendered harmless in meat is to cook it, but because of the
tradition of eating country food, Raven said there are outbreaks of the disease
every year in Nunavut.
"I found it pretty
amazing that the Keewatin has the highest rate of trichinosis in Canada and
even the entire United States. We have more trichinosis in Nunavut than the
United States does."
The cost of one case of
trichinosis in an individual is also extremely expensive. Medication can cost
more than $800 per infection.
"Thats just
for the antibiotics, then you throw in the repeated blood work thats necessary,
the transportation costs, lab costs, investigation costs," Raven said.
The department is getting
a helping hand in setting up its program from scientists at the Nunavik Research
Centre who struggled to organize their own program in the 1990s.
The centres Dr. Bill
Doidge said after persuading the federal government that trichinosis was indeed
a public health issue in Nunavik, a specific test for walrus meat was developed.
"Walrus is where theres
a health issue. Trichonella worms are also in polar bear, but the traditional
knowledge is you need to cook polar bear meat so its not really a health
issue," he said.
Scientists initially tested
about 100 seals and didnt find any positive samples, he said, so it doesnt
seem to be a problem, although it has been reported in scientific literature.
In 1995 they decided to
centralize a testing lab in Kuujjuaq, even though many of the cases were coming
from Salluit. Seven years later, Doidge said, almost all walrus harvested in
Nunavik are tested for the infection.
"This year we did
53 walrus for Nunavik and the year before it was 54," he said. "This
was a good year for walrus hunters in that only one of the 54 walrus were infected,
whereas last year, 2001, there was more like seven infected. The program itself
has been quite successful in greatly reducing the cases of human trichinellosis."
Work is continuing on finding
out how walrus, which are mainly bottom-feeders, catch a parasite that is only
transmitted by ingesting raw infected meat, and where the hot spots for the
infection are.
"Its a really
tough little worm," Doidge said, " We had some polar bear stuff that
was in the freezer for two years and then after the digestive process they were
still alive. Theyre tough little buggers."
Tough as the parasite is,
these two labs will mean people who use the testing services can still enjoy
raw walrus meat without having to worry about getting sick.
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