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, Nunavut’s 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 there’s 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 it’s caught when the parasite is still in the person’s stomach it can be treated with antibiotics, but if it has already migrated in cyst form to the muscles, it’s 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.

"That’s just for the antibiotics, then you throw in the repeated blood work that’s 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 centre’s 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 there’s a health issue. Trichonella worms are also in polar bear, but the traditional knowledge is you need to cook polar bear meat so it’s not really a health issue," he said.

Scientists initially tested about 100 seals and didn’t find any positive samples, he said, so it doesn’t 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.

"It’s 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. They’re 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.