Characterization of a non-pathogenic H5N1 influenza virus isolated from a migratory duck flying from Siberia in Hokkaido, Japan, in October 2009

Abstract

BackgroundInfection with H5N1 highly pathogenic avian influenza viruses (HPAIVs) of domestic poultry and wild birds has spread to more than 60 countries in Eurasia and Africa. It is concerned that HPAIVs may be perpetuated in the lakes in Siberia where migratory water birds nest in summer. To monitor whether HPAIVs circulate in migratory water birds, intensive surveillance of avian influenza has been performed in Mongolia and Japan in autumn each year. Until 2008, there had not been any H5N1 viruses isolated from migratory water birds that flew from their nesting lakes in Siberia. In autumn 2009, A/mallard/Hokkaido/24/09 (H5N1) (Mal/Hok/24/09) was isolated from a fecal sample of a mallard (Anas platyrhynchos) that flew from Siberia to Hokkaido, Japan. The isolate was assessed for pathogenicity in chickens, domestic ducks, and quails and analyzed antigenically and phylogenetically.ResultsNo clinical signs were observed in chickens inoculated intravenously with Mal/Hok/24/09 (H5N1). There was no viral replication in chickens inoculated intranasally with the isolate. None of the domestic ducks and quails inoculated intranasally with the isolate showed any clinical signs. There were no multiple basic amino acid residues at the cleavage site of the hemagglutinin (HA) of the isolate. Each gene of Mal/Hok/24/09 (H5N1) is phylogenetically closely related to that of influenza viruses isolated from migratory water birds that flew from their nesting lakes in autumn. Additionally, the antigenicity of the HA of the isolate was similar to that of the viruses isolated from migratory water birds in Hokkaido that flew from their northern territory in autumn and different from those of HPAIVs isolated from birds found dead in China, Mongolia, and Japan on the way back to their northern territory in spring.ConclusionMal/Hok/24/09 (H5N1) is a non-pathogenic avian influenza virus for chickens, domestic ducks, and quails, and is antigenically and genetically distinct from the H5N1 HPAIVs prevailing in birds in Eurasia and Africa. H5 viruses with the HA gene of HPAIV had not been isolated from migratory water birds in the surveillance until 2009, indicating that H5N1 HPAIVs had not become dominant in their nesting lakes in Siberia until 2009.

Pathogenicity of an H5N1 Highly Pathogenic Avian Influenza Virus Isolated in the 2010–2011 Winter in Japan to Mandarin Ducks

“…The pre-and post-serum HI titers of #05 against non-pathogenic H5 virus, A/tundra swan/Shimane/3211A001/2011 (H5N2), were 16HI and 8HI, respectively (data not shown). It was formerly reported that there were some differences in antigenicity of H5 HAs between HPAIV and non-pathogenic viruses [12,14,22]. Therefore, #05 was thought to be previously exposed to non-pathogenic H5 virus.…”

Characterization of Highly Pathogenic Avian Influenza Virus A(H5N6), Japan, November 2016

“…B. swan, black swan; Ck, chicken; HK, Hong Kong; Hok, Hokkaido; Mal, mallard; Pf, peregrine falcon; Ws, whooper swan. †Low pathogenic avian influenza viruses isolated from mallard ( 15 ) and chicken in Japan.…”

Natural history of highly pathogenic avian influenza H5N1

“…The introduced H5N1 viruses represented three different subgroups indicating at least three separate introduction events and were closely related to virus isolates from China, Mongolia, Russia, Romania and Bulgaria (2009 – 2010) (Kajihara et al, 2011; Sakoda et al, 2012; Marinova-Petkova et al, 2012). Closely related clade 2.3.2.1 H5N1 viruses were detected in South Korea in wild birds (including various duck species, whooper swan, white-fronted goose, and predators) and during domestic poultry outbreaks (chicken, quail, turkey, duck) from December 2010 until spring 2011 (Kim et al, 2012; Kwon et al, 2011; Sakoda et al, 2010; Yamamoto et al, 2011). Throughout Japan several outbreaks of HPAI H5N1 occurred in wild birds (migratory duck, swan, grebe species; predators) and poultry (chicken) farms from late 2010 until March 2011 (Sakoda et al, 2012).…”