Retrospective investigation of Echinococcus canadensis emergence in translocated elk (Cervus canadensis) in Tennessee, USA, and examination of canid definitive hosts.

Background: Few reports of Echinococcus spp. have been described in the USA; however, the geographical distribution of Echinococcus spp. in wild hosts is increasing consequent to human activities. In the early 2000's, 253 elk (Cervus canadensis) originating from Alberta, Canada were released into the Great Smoky Mountains National Park and North Cumberland Wildlife Management Area in an effort to re-establish their historical range.
Methods: We investigated the prevalence of Echinococcus spp. in re-established elk populations in the North Cumberland Wildlife Management Area and the Great Smoky Mountains National Park via a retrospective analysis of banked elk tissues and helminth examinations on intestinal contents from coyotes (Canis latrans) from the North Cumberland Wildlife Management Area.
Results: Four elk were PCR and sequence positive for E. canadensis. Each sequence had 98% or greater coverage and identity to multiple E. canadensis genotypes on GenBank. Adult Echinococcus spp. were not detected in any of the coyotes examined in this study.
Conclusions: Continued surveillance of this disease in susceptible species in these areas is warranted, and these data further underscore the risk of zoonotic pathogen introduction secondary to wildlife translocation.