High prevalence, intensity, and genetic diversity of Trichinella spp. in wolverine (Gulo gulo) from Yukon, Canada

• Published in: Parasites & Vectors
• Main Authors: Rajnish Sharma, N. Jane Harms, Piia M. Kukka, Thomas S. Jung, Sarah E. Parker, Sasha Ross, Peter Thompson, Benjamin Rosenthal, Eric P. Hoberg, Emily J. Jenkins
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2021
• Subjects: Trichinella spp; Wolverine; Canada; Prevalence; T. nativa; Trichinella T6; Infectious and parasitic diseases; RC109-216; Yukon; Gulo gulo
• Online Access: https://doi.org/10.1186/s13071-021-04636-2; https://doaj.org/article/6ecb734bf6604f9c923af4f1f4e73e82

Abstract Background Species of Trichinella are globally important foodborne parasites infecting a number of domestic and wild vertebrates, including humans. Free-ranging carnivores can act as sentinel species for detection of Trichinella spp. Knowledge of the epidemiology of these parasites may help prevent Trichinella spp. infections in northern Canadian animals and people. Previous research on Trichinella spp. in wildlife from Yukon did not identify risk factors associated with infection, or the diversity and identity of species of Trichinella in regional circulation, based on geographically extensive sampling with large sample sizes. Methods In a cross-sectional study, we determined the prevalence, infection intensity, risk factors, and species or genotypes of Trichinella in wolverine (Gulo gulo) in two regions of Yukon, Canada, from 2013–2017. A double separatory funnel digestion method followed by mutiplex PCR and PCR-RFLP were used to recover and identify species of Trichinella, respectively. Results We found larvae of Trichinella in the tongues of 78% (95% CI 73–82) of 338 wolverine sampled. The odds of adult (≥ 2 years) and yearling (1 year) wolverine being Trichinella spp.-positive were four and two times higher, respectively, compared to juveniles (<1 year). The odds of Trichinella spp. presence were three times higher in wolverine from southeast than northwest Yukon. The mean intensity of infection was 22.6 ± 39 (SD, range 0.1–295) larvae per gram. Trichinella T6 was the predominant genotype (76%), followed by T. nativa (8%); mixed infections with Trichinella T6 and T. nativa (12%) were observed. In addition, T. spiralis was detected in one wolverine. Out of 22 isolates initially identified as T. nativa in multiplex PCR, 14 were analyzed by PCR-RFLP to distinguish them from T. chanchalensis, a recently discovered cryptic species, which cannot be distinguished from the T. nativa on multiplex PCR. Ten isolates were identified either as T. chanchalensis alone (n = 7), or mixed infection with T. ...