Revealing the northern distribution of Trichinella chanchalensis: New geographic records from Nunavut and ecological perspectives

Abstract

Trichinella is a genus of foodborne nematode parasites that comprises 13 taxa. In northern Canada three taxa, T. nativa, T6, and the recently discovered T. chanchalensis, are commonly found in wild carnivores. These parasites are of public health concern, particularly in northern Canada, where human infection rates are markedly higher. Our first objective was to determine whether T. chanchalensis, reported in Alaska, Yukon, and the Northwest Territories (NT), is present in wolverines from Nunavut. Our second objective was to determine the prevalence of co-infections and competition among Trichinella spp. Tongue samples were collected from 100 wolverines, from Nunavut and NT. Trichinella spp. larvae were isolated using the artificial digestion method, quantified (calculated as larvae per gram of muscle, LPG), and identified using next-generation sequencing (NGS). Trichinella spp. larvae were detected in 76/100 (76 %) of wolverines, with higher prevalence and infection intensity in Nunavut (82 %, 16.7 LPG) than in NT (70 %, 8.0 LPG). We detected all three taxa in both territories, with co-infections more common in NT (90 %) than in Nunavut (68 %). We found no significant negative associations in the presence or abundance between T. nativa and T6, suggesting minimal competition in the host muscle tissue. We report a new geographic record for T. chanchalensis in Nunavut and demonstrate the utility of NGS for Trichinella spp. genotyping and detecting co-infections. Building on these findings and prior work, we propose hypotheses regarding the origin of T. chanchalensis and suggest approaches for clarifying the taxonomic status of T6.