Prevalence and geographic distribution of Echinococcus genus in wild canids in southern Québec, Canada.

Echinococcus spp. is an emerging zoonotic parasite of high concern. In Canada, an increase in the number of human and animal cases diagnosed has been reported, but information regarding the parasite's distribution in wildlife reservoir remains limited. A cross-sectional study was conducted to estimate the prevalence of wild canids infected with Echinococcus spp. and Echinococcus multilocularis in areas surrounding populated zones in Québec (Canada); to investigate the presence of areas at higher risk of infection; to evaluate potential risk factors of the infection; and as a secondary objective, to compare coproscopy and RT-PCR diagnostic tests for Taenia spp. and Echinococcus identification. From October 2020 to March 2021, fecal samples were collected from 423 coyotes (Canis latrans) and 284 red foxes (Vulpes vulpes) trapped in 12 administrative regions. Real-time PCR for molecular detection of genus Echinococcus spp. and species-specific Echinococcus multilocularis were performed. A total of 38 positive cases of Echinococcus spp., of which 25 were identified as E. multilocularis, were detected. Two high-risk areas of infection were identified. The prevalence of Echinococcus spp. was 22.7% (95% CI 11.5–37.8%) in the Montérégie centered high-risk area, 26.5% (95% CI 12.9–44.4%) in the Bas-St-Laurent high-risk area, and 3.0% (95%CI 1.8–4.7%) outside those areas. For E. multilocularis, a prevalence of 20.5% (95% CI 9.8–35.3%) was estimated in the high-risk area centered in Montérégie compared to 2.4% (95% CI 1.4–3.9%) outside. Logistic regression did not show any association of infection status with species, sex, or geolocation of capture (p > 0.05). This study shows the circulation of Echinococcus in a wildlife cycle in 9/12 administrative regions of Québec. Author summary: Echinococcus spp., including E. multilocularis, are zoonotic parasites spread by wild canids that exhibit spatial expansion and emergence in North America. Given their ability to cause severe lesions and mortality in the absence of treatment, the recent detection of the first human case of E. multilocularis in Québec in 2018 raised significant public health concerns. In this study, we estimated the prevalence and described the spatial distribution of infection with parasites of the genus Echinococcus in coyotes (Canis latrans) and red foxes (Vulpes vulpes) near populated areas in southern Québec. A total of 707 carcasses of coyotes and red foxes were collected from 12 administrative regions. Fecal samples from each carcass were analyzed using microscopy-based and molecular methods. We detected Echinococcus spp. and E. multilocularis in 8/12 of the studied areas. We found two high-risk areas of infection. Our results demonstrate that Echinococcus spp. is circulating in Québec and highlight the importance of implementing preventive measures to limit human and domestic animal infections and of raising awareness among at risk animal populations. [ABSTRACT FROM AUTHOR]