title: Very virulent infectious bursal disease virus isolated from wild birds in Korea: epidemiological implications.
abstract: To explore the epidemiological link between infectious bursal disease virus (IBDV) in wild birds and domestic chickens in Korea, we examined 107 free-living wild birds, representing 7 species, that were found dead of apparent natural causes in Korea over the past two years for the presence of IBDV. Five birds were tested positive for IBDV by RT-PCR assay: black-billed magpie (n=1), mallard duck (n=2), bean goose (n=1) and white-fronted goose (n=1). IBDV was isolated from RT-PCR-positive tissues following chicken embryo inoculation. Sequence analysis of the VP2 gene indicated that all of the isolates from the wild birds encode amino acids A222, I242, I256, I294 and S299 of VP2, which are conserved among strains of very virulent IBDV (vvIBDV). Phylogenetic analysis revealed that the wild bird IBDV isolates are closely related to strains of vvIBDV. An IBDV isolate from a magpie showed 60% mortality in SPF chickens and severe bursal atrophy. The epidemiological implications of IBDV in free-living wild birds are discussed. To our knowledge, this is the first report of vvIBDV in free-living wild birds.
authors.affiliation: Avian Disease Division, National Veterinary Research Institute, Gyeonggi, South Korea.
authors.forename: Woo-Jin
authors.initials: WJ
authors.lastname: Jeon
authors.forename: Eun-Kyoung
authors.initials: EK
authors.lastname: Lee
authors.forename: Seong-Joon
authors.initials: SJ
authors.lastname: Joh
authors.forename: Jun-Hun
authors.initials: JH
authors.lastname: Kwon
authors.forename: Chang-Bum
authors.initials: CB
authors.lastname: Yang
authors.forename: Yeo-Sung
authors.initials: YS
authors.lastname: Yoon
authors.forename: Kang-Seuk
authors.initials: KS
authors.lastname: Choi
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology; D001715:Bird Diseases / Q000453:epidemiology* / Q000401:mortality / Q000821:virology*; D001717:Birds / Q000821:virology; D018175:Birnaviridae Infections / Q000453:epidemiology / Q000401:mortality / Q000662:veterinary* / Q000821:virology; D002642:Chick Embryo; D002645:Chickens; D007243:Infectious bursal disease virus / Q000302:isolation & purification / Q000472:pathogenicity*; D007723:Korea / Q000453:epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D015678:Viral Structural Proteins / Q000235:genetics; D014774:Virulence / Q000235:genetics
chemical_list: C082513:VP2 protein, infectious bursal disease virus; D015678:Viral Structural Proteins