Urban coyotes a factor in rise of serious parasitic disease in western Canada: U of A

EDMONTON -

Alberta is now a hot spot for a rare and potentially fatal disease known as alveolar echinococcosis (AE) -- a parasitic infection transmitted from canines.

According to a University of Alberta Faculty of Medicine and Dentistry report, the disease which orignated from Europe has become established in Alberta, Saskatchewan and British Columbia. There have been a total of 17 cases found in Alberta. 

The parasite takes the form of a small tapeworm in canines such as coyotes, foxes and pet dogs, according to University of Alberta infectious diseases expert Stan Houston. The tapeworm is harmless to canines but if a rodent consumes the parasitic feces, this can be fatal for the rodent. When the canine eats the rodent, the tapeworm can find itself back inside the canine, said Houston.

Humans can become infected with the disease if the parasitic egg is accidently consumed. If we consume lettuce or strawberries grown where a coyote has passed through, this can lead to infection, according to a U of A report. 

Humans are also at risk of contracting the disease by petting a dog with AE.

“A human could become infected by petting a dog that has microscopic traces of canine feces in its hair and then touching food or their mouth, accidentally ingesting the parasite’s eggs,” said Houston.

AE has spread quickly in Alberta due to two main factors: an increase of human contact with coyotes and an increase in people with diseases that weaken the immune system.

“In coyotes in Calgary and in Edmonton, more than half have been found to be carrying this parasite. So the new strain seems to not only be more virulent when it affects humans, but it seems to be super-effective in wild hosts,” said Houston.

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Symptoms of AE can be difficult to spot or take several years to appear. Almost half of Alberta cases were found accidently when testing for a different illness. Symptoms of AE include:

• Unspecified pain

• Jaundice

• Weakness

• Weight loss

The symptoms of AE are similar to conditions of liver cancer, said an expert. If the disease is left untreated, it could kill its host in 10 to 15 years.

To prevent contracting the disease, experts recommend good hygiene and taking simple precautions such as washing your hands after you pet your dog and washing produce that comes from the ground.

“We should be paying attention, but it’s still a very rare disease,” said Houston. “People should keep that in perspective, adopt health behaviours and not obsess about this.”

More on the study can be found online.