title: Reintroduction of H5N1 highly pathogenic avian influenza virus by migratory water birds, causing poultry outbreaks in the 2010-2011 winter season in Japan.
abstract: H5N1 highly pathogenic avian influenza virus (HPAIV) was reintroduced and caused outbreaks in chickens in the 2010-2011 winter season in Japan, which had been free from highly pathogenic avian influenza (HPAI) since 2007 when HPAI outbreaks occurred and were controlled. On 14 October 2010 at Lake Ohnuma, Wakkanai, the northernmost part of Hokkaido, Japan, H5N1 HPAIVs were isolated from faecal samples of ducks flying from their nesting lakes in Siberia. Since then, in Japan, H5N1 HPAIVs have been isolated from 63 wild birds in 17 prefectures and caused HPAI outbreaks in 24 chicken farms in nine prefectures by the end of March in 2011. Each of these isolates was genetically closely related to the HPAIV isolates at Lake Ohnuma, and those in China, Mongolia, Russia and Korea, belonging to genetic clade 2.3.2.1. In addition, these isolates were genetically classified into three groups, suggesting that the viruses were transmitted by migratory water birds through at least three different routes from their northern territory to Japan. These isolates were antigenic variants, which is consistent with selection in poultry under the immunological pressure induced by vaccination. To prevent the perpetuation of viruses in the lakes where water birds nest in summer in Siberia, prompt eradication of HPAIVs in poultry is urgently needed in Asian countries where HPAI has not been controlled.
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Yoshihiro
authors: Y
authors: Sakoda
authors: Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Laboratory of Veterinary Public Health, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Hiroshi
authors: H
authors: Ito
authors: Research Team for Zoonotic Diseases, National Institute of Animal Health, Tsukuba 305-0856, Japan.
authors: Yuko
authors: Y
authors: Uchida
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Masatoshi
authors: M
authors: Okamatsu
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Naoki
authors: N
authors: Yamamoto
authors: Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Kosuke
authors: K
authors: Soda
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Naoki
authors: N
authors: Nomura
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Saya
authors: S
authors: Kuribayashi
authors: Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Shintaro
authors: S
authors: Shichinohe
authors: Laboratory of Comparative Pathology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Yuji
authors: Y
authors: Sunden
authors: Laboratory of Comparative Pathology, Department of Veterinary Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Takashi
authors: T
authors: Umemura
authors: Laboratory of Veterinary Hygiene, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Tatsufumi
authors: T
authors: Usui
authors: Laboratory of Veterinary Microbiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Hiroichi
authors: H
authors: Ozaki
authors: Laboratory of Veterinary Hygiene, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Tsuyoshi
authors: T
authors: Yamaguchi
authors: Laboratory of Veterinary Microbiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Toshiyuki
authors: T
authors: Murase
authors: Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.|Laboratory of Veterinary Public Health, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
authors: Toshihiro
authors: T
authors: Ito
authors: Research Team for Zoonotic Diseases, National Institute of Animal Health, Tsukuba 305-0856, Japan.
authors: Takehiko
authors: T
authors: Saito
authors: Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan.
authors: Ayato
authors: A
authors: Takada
authors: Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi 332-0012, Japan.|Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan.|Laboratory of Microbiology, Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors: Hiroshi
authors: H
authors: Kida
mesh_terms: D000818:Animals; D001717:Birds; D002645:Chickens; D016000:Cluster Analysis; D004196:Disease Outbreaks; D004372:Ducks; D005243:Feces / Q000821:virology; D014644:Genetic Variation; D005838:Genotype; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000276:immunology; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D007564:Japan / Q000453:epidemiology; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D007252:Influenza Vaccines; D012367:RNA, Viral