Nationwide tracking sought for rare disease that is spread by canines, fatal if untreated

As cases creep upward of a rare disease that spreads to humans from wild canines and dogs, medical experts say it's important to get a better understanding of its incidence across the country.

Alveolar echinococcosis (AE) is an infection caused by the parasite echinococcus multilocularis, which is carried by coyotes, dogs and foxes. The tapeworm common in Europe was first detected in wildlife in western Canada; one year later, the first human case of AE was found in a woman in rural Alberta.

Since then, 30 more people in Alberta alone have received the same diagnosis, including more than a dozen cases since 2020.

"There have been cases diagnosed across the country now but to my knowledge, not as many as in Alberta and particularly in northern Alberta," said Dr. Dave Waldner, an infectious diseases doctor at the University of Alberta who cares for patients with the condition. 

According to infectious diseases surveillance reports, there have been four cases reported in Ontario since 2017. Cases have also been identified in Saskatchewan and B.C.

Waldner said experts are planning to meet later this month to discuss starting a nationwide registry to develop a better understanding of the disease across Canada.

"We'll hopefully know more in the coming months," he said.

Dave Rajotte, who has a livestock farm in Peebles, Sask., was diagnosed with AE last year after going to the hospital with stomach pain. At the time, he thought he was having problems with his gallbladder.

It turned out he had a large tumour in his liver. 

Rajotte does not know how he contracted the disease, but he has a hunch it came from a dog he'd spent a lot of time with that had a large tumour on its abdomen.

Waldner said it's not easy to determine how people were infected but the majority of his patients have been dog owners. About two-thirds of his patients have been individuals who live in rural areas, the rest have been found among people in the Edmonton area. 

Animals pass infectious eggs in their stool, which humans can inadvertently ingest. 

In the vast majority of cases, Waldner said, the infection goes to the liver and forms a mass. The process is so slow that most people have no symptoms; the mass is only discovered after they've undergone scans for other reasons. 

In about a third of his cases, patients have sought care because they were dealing with larger masses causing pain or blockages, Waldner said.