Echinococcus in wild canids in Québec (Canada) and Maine (USA)

Zoonotic Echinococcus spp.cestodes (E.canadensis and E. multilocularis) infect domestic animals, wildlife, and people in regions of Canada and the USA.We recovered and quantified Echinococcus spp.cestodes from 22 of 307 intestinal tracts of wild canids (23 wolves, 100 coyotes, 184 red and arctic foxes) in the state of Maine and the province of Que ´bec.We identified the species and genotypes of three Echinococcus spp.cestodes per infected animal by sequencing mitochondrial DNA at two loci.We further confirmed the absence of E. multilocularis by extracting DNA from pools of all cestodes from each animal and running a duplex PCR capable of distinguishing the two species.We detected E. canadensis (G8 and G10), but not E. multilocularis, which is emerging as an important human and animal health concern in adjacent regions.Prevalence and median intensity of E. canadensis was higher in wolves (35%, 460) than coyotes (14%, 358).This parasite has historically been absent in Atlantic regions of North America, where suitable intermediate hosts, but not wolves, are present.Our study suggests that coyotes are serving as sylvatic definitive hosts for E. canadensis in Atlantic regions, and this may facilitate eastward range expansion of E. canadensis in the USA and Canada.As well, compared to wolves, coyotes are more likely to contaminate urban green spaces and peri-urban environments with zoonotic parasites. Author summaryEchinococcosis is a zoonosis caused by ingestion of tapeworm eggs in feces of wild or domestic canids (e.g.foxes, wolves, coyotes, and dogs).In North America, the number of new human echinococcosis cases reported annually is low; however, recent reports of these parasites in unusual presentations, in new locations, and in wildlife near urban areas have caused renewed interest by veterinary and human health professionals.In a crossborder collaboration, we examined the intestines of wolves (Canis lupus), coyotes (C.latrans) and foxes (Vulpes vulpes, V. lagopus) trapped in Que ´bec (Canada) and neighboring Maine (USA), using genetic tools to identify Echinococcus tapeworms.We did not detect E. multilocularis, a serious threat to human health that has recently emerged in