Trichinella pseudospiralis in a wolverine (Gulo gulo) from the Canadian North

Authors: SHARMA, RAJNISH - University Of Saskatchewan; THOMPSON, PETER - Non ARS Employee; ELKIN, BRETT - Government Of The Northwest Territories; MULDERS, ROBERT - Government Of The Northwest Territories; BRANIGAN, MARSHA - Government Of The Northwest Territories; PONGRACZ, JODIE - Government Of The Northwest Territories; WAGNER, BRENT - University Of Saskatchewan; SCANDRETT, BRAD - Canadian Food Inspection Agency; HOBERG, ERIC - University Of New Mexico; Rosenthal, Benjamin; JENKINS, EMILY - University Of Saskatchewan

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2019
Publication Date: 8/1/2019
Citation: Sharma, R., Thompson, P., Elkin, B., Mulders, R., Branigan, M., Pongracz, J., Wagner, B., Scandrett, B., Hoberg, E., Rosenthal, B.M., Jenkins, E. 2019. Trichinella pseudospiralis in a wolverine (Gulo gulo) from the Canadian North. Journal of Parasitology. 9:274-280. https://doi.org/10.1016/j.ijppaw.2019.06.005.
DOI: https://doi.org/10.1016/j.ijppaw.2019.06.005

Interpretive Summary: Foodborne parasites are a risk in communities, such as in northern Canada, where wild came is consumed raw or after preparation using traditional smoking or drying practices. Definitive diagnosis seldom justifies the presumption that most outbreaks there derive from exposure to either of two freeze-resistant types of Trichinella. Here, a team of Canadian and USDA scientists discovered an unexpected species of Trichinella in a wolverine from the Northwest Territories. Trichinella psuedospiralis may have been transported to this region by migratory birds. Infection in wolverines should not pose a direct food safety risk for trichinellosis, however its presence suggests the possibility that the local food supply may harbour such infections, which differ in appearance from the parasites previously suspected in the region, complicating their timely detection. These findings will be of interest to food safety professionals, epidemiologists, and hunters and consumers of wild game who may be at risk for a previously unsuspected disease agent.

Technical Abstract: Species of Trichinella are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. Trichinella spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the north are generally attributed to T. nativa (T2) or the T6 genotype; however, genetic characterization is seldom performed, precluding definitive diagnosis. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine (Gulo gulo) from the Northwest Territories. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for T. pseudospiralis in northern Canada. Multiplex PCR and sequencing of fragments of the Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetic analysis linked this isolate with others derived from the Palearctic or Neotropical regions. We suggest that migratory birds might have played a role in the long distance dispersal of this pathogen. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for trichinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for T. pseudospiralis. Along with the infection risk already recognized for T. nativa and Trichinella T6, our observations emphasize the need for further studies using molecular diagnostics to clarify if this is a solitary finding or if T. pseudospiralis circulates in the Canadian Arctic.