Prevalence and distribution of Echinococcus species in domestic dogs and wild canids in Pennsylvania: KeyScreen® GI Parasite PCR testing of fecal samples

Echinococcus species are zoonotic cestodes found worldwide, posing a risk to humans and animals. Echinococcus multilocularis and E. granulosus sensu lato (s.l.) are both a concern in North America. Wild and domestic canids are definitive hosts, while rodents and ruminants are intermediate hosts for E. multilocularis and E. granulosus s.l., respectively. Humans can be alternative intermediate hosts for both Echinococcus species, and domestic dogs can serve as intermediate hosts for E. multilocularis. Recent Echinococcus detections in the eastern United States and Canada indicate a need for surveillance for these parasites. In total, we tested 27,293 fecal samples: pet dogs (n = 26,979), hunting dogs (n = 52), and wild canids (n = 262, including coyotes (Canis latrans), red fox (Vulpes vulpes), and gray fox (Urocyon cinereoargenteus)) from Pennsylvania, USA using the KeyScreen™ GI Parasite PCR. This PCR can detect and differentiate E. multilocularis, E. granulosus s.l., and Taenia spp. Infection with Echinococcus multilocularis was detected in four individuals: two gray foxes from Erie and Clearfield counties and two coyotes from Lackawanna and Susquehanna counties. Additionally, one coyote was positive from Wyoming county for E. canadensis (G8), an E. granulosus s.l. species. No pet dogs or hunting dogs were positive for either Echinococcus species. Wild canids from multiple counties were positive for Taenia species, but no domestic pet dogs or hunting dogs were positive. These findings expand the known range of Echinococcus species in Pennsylvania wild canids and demonstrate that KeyScreen™ is a valuable and rapid tool for detecting Echinococcus spp. in canid fecal samples.