Relatively Low Prevalence and Genetic Diversity of Trichinella nativa in Wolverines (Gulo gulo) from Churchill, Manitoba, Canada.

Abstract

In the Canadian North, trichinellosis is a zoonotic disease that is primarily transmitted by the consumption of improperly cooked walrus (Odobenus rosmarus) and bear (Ursus spp.) meat. Trichinella spp. infections in other wildlife provide information about where transmission occurs, the species present, and the potential risk of transmission to humans. Wolverines (Gulo gulo) can serve as a sentinel species, due to their scavenging behavior, high trophic level, and high larval burden when infected. We determined the prevalence, intensity, and genetic diversity of Trichinella infections in wolverines in Churchill, Manitoba, Canada, and compared these results with those of studies conducted in other northern Canadian provinces. Larvae were found in 41% (9/22) of hosts, with a mean intensity of 5.93 larvae per gram of tongue tissue. The DNA sequencing of the cytochrome b gene confirmed that all hosts were infected with Trichinella nativa and that diversity was limited with only two distinct haplotypes recovered. The presence of T. nativa in wolverines indicates that this parasite is being maintained in a sylvatic cycle and that humans could be at risk of transmission in northern Manitoba.