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

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 arctic and subarctic regions of Canada and the United States are generally attributed to T. nativa (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine ( Gulo gulo ) from the Northwest Territories of Canada. 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 . Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that migratory birds might have played a role in the dispersal of this pathogen 1000's of km to northwestern Canada. 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 infection risk already recognized for T. nativa and Trichinella T6, our observations emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if T. pseudospiralis and other freeze susceptible species of Trichinella (such as T. spiralis ) circulate more broadly in wildlife in Canada, and elsewhere.

From wildlife to humans: The global distribution of Trichinella species and genotypes in wildlife and wildlife-associated human trichinellosis

“…Trichinella pseudospiralis was first reported in wildlife in the Americas in 1995 in Alabama, United States ( Lindsay et al, 1995 ). Since then, it has been reported elsewhere in the southern United States as well as on Vancouver Island, British Columbia in Canada in 2010 and the Northwest Territories in 2019 ( Table 20 ) ( Gajadhar and Forbes, 2010 ; Sharma et al, 2019 ). Trichinella pseudospiralis is a freeze-susceptible species which typically limits the northern geographic extent, but it has been reported in the subarctic of Canada in the Northwest Territories, possibly adventitiously introduced through migratory birds ( Sharma et al, 2019 ).…”

Research on Selected Wildlife Infections in the Circumpolar Arctic—A Bibliometric Review

“…In the Arctic, an important survival factor for the parasite is resistance to freezing, which enables transmission to carrion feeders even from carcasses of animals that died during the winter. Three of the thirteen species/genotypes known are considered especially freeze-resistant, and their known distribution is limited to the Arctic and subarctic [ 24 , 25 , 26 ]. Altogether, there were 39 articles included about Trichinella spp.…”

Non-Encapsulated Trichinella Species: T. pseudo spiralis, T. papuae and T. zimbawensis

“…Non-encapsulated Trichinella Species: T. pseudo spiralis, T. papuae and T. zimbawensis DOI: http://dx.doi.org/10.5772/intechopen.105680 has also been detected in raccoon dogs in Germany [21][22][23], American mink in Poland [24], cougars from Colorado, United States [25], red foxes in Poland [26], raccoon dogs in Central Europe [27], wolverines from the Canadian north [28], Eurasian blackbird from Armenia [29], wild boars in Estonia [30], red kite from Italy [31], wolf from Central Italy [32], bobcats from Oklahoma [33]. T. pseudospiralis infection in red-eared sliders was found to be influenced by environmental temperature, as the infection was successful in turtles maintained at 38°C compared to those reared at 32°C and 28°C [32].…”