Surveillance for in Hunter-Harvested Wild-Elk () from Pennsylvania, USA (2016-2017).

is a tick-borne protozoal parasite which infects the erythrocytes of members of the families Cervidae and Bovidae. Infection can result in hemolytic anemia, lethargy, anorexia, and death. The reservoir host of is the white-tailed deer (); however, infections with overt disease have only been documented in reindeer (), caribou () and captive elk (). Infected elk may remain asymptomatic, creating the risk for dissemination of the pathogen when elk are relocated. Additionally, infected asymptomatic elk may contribute to the spread of in the local wildlife/captive population via feeding ticks. Information regarding endemic regions of infection is limited due to frequent asymptomatic infections and a lack of targeted surveillance of in wildlife. To obtain data on infection in wild elk in Pennsylvania, we tested blood samples collected from 190 hunter-harvested wild elk between 2016 and 2017. Of the 190 blood samples tested, 18.4% (35/190) tested positive for spp. Genetic sequencing of the positive samples showed a 98.0-100.0% match for . No other species were identified. Results of this study documents infection within hunter-harvested wild elk from Pennsylvania.