A tiny tapeworm that can make people seriously ill is now common in wildlife throughout Alberta, researchers at the University of Calgary’s faculty of veterinary medicine have found.
The parasitic tapeworm called echinococcus multilocularis (E. multilocularis) is common in Europe and was first detected in wildlife in Western Canada in 2012. A year later, the first human case of a tumour-like disease caused by the tapeworm (human alveolar echinococcosis or AE), was diagnosed.
Since 2016, six more people in Alberta have been diagnosed with this potentially fatal disease, which develops slowly over several years and causes multiplying lesions in the body, usually in the liver. People with compromised immune systems are most at risk. Undetected, the condition can spread to other organs and, if diagnosed too late, can be fatal.
“This evidence is the smoking gun that these AE cases are locally acquired, and they are caused by an invasive strain coming from Europe that has spread all over Alberta,” said Dr. Alessandro Massolo, an adjunct professor of wildlife health ecology. “This European strain is known to be very virulent for people, and now is everywhere in wildlife and even in dogs.”
Recent studies of coyotes, foxes, and rodents in the province have found a high incidence of infected wild animals in areas across Alberta, including urban off-leash dog parks in Calgary. The infection is spread through the feces of coyotes and foxes that have eaten infected rodents. Dogs and cats get the infection through contact with feces or eating infected rodents, then developing adult worms and passing eggs in their feces.
People can become infected by eating fruit or vegetables contaminated with parasitic eggs. The eggs aren’t visible to the human eye, so the infection can also happen from hand-to-mouth contact after handling contaminated soil or an infected pet’s fur.
“For pet owners, careful hygiene is important, as is regular veterinary care for their cats and dogs,” said Massolo.