title: Yemen and Vietnam capripoxviruses demonstrate a distinct host preference for goats compared with sheep.
abstract: Sheeppox and goatpox are caused by viruses that are members of the genus Capripoxvirus, and globally result in significant production losses. To improve the understanding of disease pathogenesis and evaluate host species preferences, sheep and goats were inoculated either with a capripoxvirus isolate from Yemen or from a recent outbreak in Vietnam. Blood, swabs and tissues were collected at various time points following experimental challenge and assessed for viral DNA content using real-time PCR and infectivity using virus isolation. The Yemen isolate was considerably more pathogenic in goats with 100 % mortality and morbidity compared with sheep with 0 % mortality and 100 % morbidity. The Vietnam isolate was also more pathogenic in goats with 100 % morbidity and an estimated 33 % mortality rate compared with mild morbidity and a 0 % mortality rate in sheep. Higher viral titres were observed in nasal, oral and conjunctival swabs from goats inoculated with either the Yemen or Vietnam isolate compared with those collected from sheep. Although the highest viral titres were detected in primary and secondary skin lesions in sheep and goats, the severity of clinical disease observed in each species varied according to the inoculum used. Whereas both the Yemen and Vietnam isolates clearly caused more severe disease in goats, the Yemen isolate was also moderately pathogenic in sheep. The Vietnam isolate, in contrast, caused only very mild disease in sheep. Limited DNA sequencing revealed ORF 074 of the Vietnam isolate to be identical to that of several goatpox virus isolates from China, suggesting a possible Chinese origin.
authors.affiliation: National Centre for Foreign Animal Disease, 1015 Arlington Street, Winnipeg MB, Canada. babiuks@inspection.gc.ca
authors.forename: Shawn
authors.initials: S
authors.lastname: Babiuk
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Bowden
authors.forename: Geoff
authors.initials: G
authors.lastname: Parkyn
authors.forename: Brett
authors.initials: B
authors.lastname: Dalman
authors.forename: Dong Manh
authors.initials: DM
authors.lastname: Hoa
authors.forename: Ngo Thanh
authors.initials: NT
authors.lastname: Long
authors.forename: Pham Phong
authors.initials: PP
authors.lastname: Vu
authors.forename: Do Xuan
authors.initials: do X
authors.lastname: Bieu
authors.forename: John
authors.initials: J
authors.lastname: Copps
authors.forename: David B
authors.initials: DB
authors.lastname: Boyle
mesh_terms: D000825:Animal Structures / Q000821:virology; D000818:Animals; D001769:Blood / Q000821:virology; D018151:Capripoxvirus / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D015511:Goat Diseases / Q000821:virology*; D006041:Goats; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods; D011213:Poxviridae Infections / Q000662:veterinary*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D012757:Sheep Diseases / Q000821:virology*; D016019:Survival Analysis; D014744:Vietnam; D015006:Yemen
chemical_list: D004279:DNA, Viral