title: Pathogenicity of emerging Japanese type 1 porcine reproductive and respiratory syndrome virus in experimentally infected pigs.
abstract: To clarify the pathogenicity of Japanese type 1 porcine reproductive and respiratory syndrome virus (PRRSV) isolate in experimentally infected pigs, we evaluated clinical signs and monitored viremia for 21 days post-inoculation (dpi). Lungs were mottled, tanned and reddish in appearance; had lesions predominantly in the cranial, middle and accessory lobes; and failed to collapse at 10 dpi. Although microscopic lesions of lungs were reproduced using the Japanese emerging type 1 PRRSV isolate under experimental conditions, no significant differences were noted between the challenge and control groups regarding mean rectal temperature and daily weight gain. These results provide useful insights into the limited pathogenicity of single infection with the Japanese type 1 PRRSV isolate in piglets, which differ from findings in reported field cases.
authors.affiliation: Viral Disease and Epidemiological Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iseki
authors.forename: Michihiro
authors.initials: M
authors.lastname: Takagi
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawashima
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shibahara
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsunemitsu
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamakawa
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D021821:Communicable Diseases, Emerging; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000821:virology; D008099:Liver / Q000821:virology; D008168:Lung / Q000821:virology; D014066:Palatine Tonsil / Q000821:virology; D019318:Porcine Reproductive and Respiratory Syndrome; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000472:pathogenicity*; D012367:RNA, Viral / Q000276:immunology; D013154:Spleen / Q000821:virology; D013552:Swine / Q000821:virology*; D019562:Viral Load; D014766:Viremia; D014774:Virulence
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral