Recent studies have found an increased presence of a tapeworm infecting coyotes, foxes, and rodents across the Canadian province of Alberta.
The research was published in the New England Journal of Medicine. Led by the University of Calgary's faculty of veterinary medicine, the findings state that a parasitic tapeworm called Echinococcus multilocularis is now prevalent in Western Canada, including in urban off-leash dog parks in Calgary.
The tapeworm was first recorded in the area in 2012, and has long since been common in Europe. The tapeworms have also been present in wildlife found in Ontario, with the latest research suggesting the parasite has been present in the region for decades - now well established.
Echinococcus multilocularis is spread through the feces of coyotes and foxes that have eaten infected rodents such as mice and rats. Tapeworm eggs can be passed through their feces, which poses a risk to other animals that come into contact with it - including humans.
Domestic pets such as dogs and cats can contract the parasite through contact with coyote feces or by also eating infected rodents. The worm can then be passed on to people via fruit, the handling of contaminated soil or through an infected pet’s fur.
The first human case of alveolar echinococcosis (AE), which is a “tumour-like disease” caused by the tapeworm was diagnosed in 2013. It develops slowly over several years and causes multiplying lesions in the body - usually in the liver. It can be fatal if not diagnosed and treated.
Since 2016, six people in Alberta have been diagnosed with the disease, according to local media.
U of C veterinarian Claudia Klein told local media sources the parasite is typically not harmful to canids, but can be up to 90% fatal if undiagnosed in humans.
While experts say there’s no real need to panic, and symptoms may take years to discover, it is advised that anyone who handles wild animals in the area should get tested for the presence of antibodies - especially hunters/trappers who handle these animals.
The life cycle of Echinococcus multilocularis. Red fox and coyote serve as main definitive hosts. Rodents such as small rodents serve as typical intermediate hosts. Man is infected as an aberrant intermediate host. (Photo | Global Burden of Alveolar Echinococcosis)