Surveillance of Echinococcus tapeworm in coyotes and domestic dogs in Winnipeg, Manitoba: Abstract

Abstract

Background: The Echinococcus species, including E. multilocularis and E. canadensis, are tapeworms that primarily infect canids such as dogs, foxes and coyotes, but which can also infect humans. In humans, E. multilocularis can cause alveolar echinococcosis; a serious condition that mimics metastatic malignancy and has a poor prognosis. It is known that coyotes in rural Manitoba are infected with Echinococcus species, but it is not known if coyotes in peri-urban areas are also infected.

Objectives: To document and map Echinococcus species in wild canids and domestic dogs in Winnipeg, Manitoba (Canada).

Methods: There were 169 fecal samples collected between April 18 and June 1, 2018. These included 44 samples of domestic dog feces, 122 of coyote scat, one of fox scat and two of coyote colonic tissue specimens. Samples were frozen (-80°C) for at least 72 hours to inactivate tapeworm ova. Polymerase chain reaction analyses of E. multilocularis and E. canadensis were performed on all frozen samples.

Results: Echinococcus multilocularis-positive samples were detected in nine (10.6%) of 85 locations, with one positive sample in a suburban Winnipeg dog park and two positive samples in a popular provincial park. No dog samples were positive for E. multilocularis; one sample was positive for E. canadensis. In contrast, nine coyote samples (7.3%) were positive for E. multilocularis and eight samples (6.5%) were positive for E. canadensis. The one fox sample was positive for each. Overall, six samples (3.6%) were positive for both infections.

Conclusion: This is the first confirmation of the presence of E. multilocularis in coyote feces in the metropolitan area of Winnipeg, Manitoba. In light of the risk this could pose to domestic dogs and human health, periodic surveillance that maps the distribution of this tapeworm could inform the need for additional public health actions.

Keywords: Echinococcus tapeworms; alveolar echinococcosis; coyotes; domestic dogs; foxes; hydatid disease; zoonotic diseases.

Figure 1

Lifecycle of Echinococcus multilocularis Source: Reprinted with permission from Torgerson PR, Keller K, Magnotta M, Ragland N. The Global Burden of Alveolar Echinococcosis. PLoS Negl Trop Dis 2010;4(6): e722

Figure 2

Map of the distribution of canid sample collection in the metropolitan area of Winnipeg, indicating Echinococcus multilocularis-positive samples A red dot indicates an E. multilocularis-positive sample for coyote scat or tissue, a yellow dot indicates an E. multilocularis-positive sample for fox scat and a black dot indicates an E. multilocularis-negative canid sample. Blue outline depicts Census Metropolitan Area of Winnipeg; used with permission from Statistics Canada (22)