title: Host and Potential Vector Susceptibility to an Emerging Orbivirus in the United States: Epizootic Hemorrhagic Disease Virus Serotype 6.
abstract: Epizootic hemorrhagic disease viruses (EHDVs) are orbiviruses transmitted by Culicoides biting midges to domestic and wild ruminants. EHDV-1 and EHDV-2 are endemic in the United States, where epizootic hemorrhagic disease is the most significant viral disease of white-tailed deer (WTD;Odocoileus virginianus) and reports of epizootic hemorrhagic disease in cattle are increasing. In 2006, a reassortant EHDV-6 was isolated from dead WTD in Indiana and has been detected each subsequent year over a wide geographic region. Since EHDV-6 is not a historically endemic serotype in the United States, it is important to understand infection outcome in potential hosts. Specifically, we aimed to evaluate the pathogenicity of the virus in 2 primary US ruminant hosts (WTD and cattle) and the susceptibility of a confirmed US vector (Culicoides sonorensis). Five WTD and 4 cattle were inoculated with >10(6)TCID50EHDV-6 by intradermal and subcutaneous injection. All 5 WTD exhibited moderate to severe disease, and 3 died. Viremia was first detected 3 to 5 days postinfection (dpi) with surviving animals seroconverting by 10 dpi. Two of 4 inoculated cattle had detectable viremia, 5 to 10 dpi and 7 to 24 dpi, respectively. No clinical, hematologic, or pathologic abnormalities were observed. Antibodies were detected by 10 dpi in 3 of 4 cows.C. sonorensis were fed on WTD blood spiked with EHDV-6 and held for 4 to 14 days postfeeding at 25°C. From 4 to 14 days postfeeding, 19 of 171 midges were virus isolation positive and 6 of 171 had ≥10(2.7)TCID50EHDV-6. Although outcomes varied, these studies demonstrate the susceptibility of ruminant and vector hosts in the United States for this recently emerged EHDV serotype.
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Ruder
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Stallknecht
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: A B
authors.initials: AB
authors.lastname: Allison
authors.affiliation: Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: D G
authors.initials: DG
authors.lastname: Mead
authors.affiliation: Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Carter
authors.affiliation: Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA howerth@uga.edu.
authors.forename: E W
authors.initials: EW
authors.lastname: Howerth
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission / Q000821:virology*; D002519:Ceratopogonidae / Q000821:virology*; D006224:Cricetinae; D003670:Deer / Q000821:virology*; D005260:Female; D018164:Hemorrhagic Disease Virus, Epizootic / Q000276:immunology*; D058507:Host Specificity; D008297:Male; D000072138:Mosquito Vectors / Q000821:virology*; D012088:Reoviridae Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D065288:Serogroup; D014481:United States; D014766:Viremia / Q000662:veterinary
keywords: Culicoides sonorensis; EHDV-6; cattle; epizootic hemorrhagic disease; experimental infection; vector; white-tailed deer