title: Genetic and pathobiological characterization of bovine viral diarrhea viruses recently isolated from cattle in Japan.
abstract: The 475 strains of bovine viral diarrhea virus (BVDV) isolated from cattle in 12 prefectures of Japan in the last 7 years were phylogenetically classified as BVDV-1 or BVDV-2 on the basis of the nucleotide sequence of the 5'-untranslated region. BVDV-1 strains were further subtyped as 1a (101 strains), 1b (163), 1c (128), 1j (3), and So CP/75-like (1), and all of the 79 BVDV-2 strains belonged to subtype 2a. These 2a BVDVs contain two isolates that had high nucleotide identities with those of highly pathogenic BVDV-2 strains reported in North America (Pellerin et al., 1994). However, acute infection with severe mortality like North American outbreak was not observed and most of the present BVDV-2 strains were isolated from persistently infected (PI) cattle showing mild or no clinical sign. Moreover, it was revealed that 61.5% of the 39 PI cattle with cytopathogenic BVDVs did not show typical mucosal disease and 54.6% of the 405 PI animals only with non-cytopathogenic BVDVs were apparently healthy. The present results indicate that the prevention of the infection with an appropriate vaccine and active surveillance covering healthy cattle are required for the control of BVD.
authors.affiliation: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Matsuno
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakoda
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Kameyama
authors.forename: Kyuzo
authors.initials: K
authors.lastname: Tamai
authors.forename: Asako
authors.initials: A
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kida
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology / Q000821:virology*; D016000:Cluster Analysis; D003967:Diarrhea / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D001908:Diarrhea Viruses, Bovine Viral / Q000235:genetics* / Q000472:pathogenicity; D005838:Genotype; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA / Q000662:veterinary
chemical_list: D020121:5' Untranslated Regions