Reassortant Highly Pathogenic H5N6 Avian Influenza Virus Containing Low Pathogenic Viral Genes in a Local Live Poultry Market, Vietnam

AbstractSites of live poultry trade and marketing are hot spots for avian influenza virus (AIV) transmission. We conducted active surveillance at a local live poultry market (LPM) in northern Vietnamese provinces in December 2016. Feces samples from the market were collected and tested for AIV. A new reassorted AIV strain was isolated from female chickens, named A/chicken/Vietnam/AI-1606/2016 (H5N6), and was found to belong to group C of clade 2.3.4.4 H5N6 highly pathogenic (HP) AIVs. The neuraminidase gene belongs to the reassortant B type. The viral genome also contained polymerase basic 2 and polymerase acidic, which were most closely related to domestic-duck-origin low pathogenic AIVs in Japan (H3N8) and Mongolia (H4N6). The other six genes were most closely related to poultry-origin H5N6 HP AIVs in Vietnam and had over 97% sequence identity with human AIV isolate A/Guangzhou/39715/2014 (H5N6). The new reassorted AIV isolate A/chicken/Vietnam/AI-1606/2016 (H5N6) identified in this study exemplifies AIVs reassortment and evolution through contact among wild birds, poultry farms, and LPMs. Therefore, active surveillance of AIVs is necessary to prevent potential threats to human and animal health.

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First Outbreak of an H5N8 Highly Pathogenic Avian Influenza Virus on a Chicken Farm in Japan in 2020

Viruses ◽

10.3390/v13030489 ◽

2021 ◽

Vol 13 (3) ◽

pp. 489

Author(s):

Saki Sakuma ◽

Yuko Uchida ◽

Momoyo Kajita ◽

Taichiro Tanikawa ◽

Junki Mine ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Highly Pathogenic Avian Influenza ◽

Animal Health ◽

Lethal Dose ◽

Clinical Signs ◽

Highly Pathogenic ◽

Pathogenic Avian Influenza ◽

Pathogenic Avian Influenza Virus

On 5 November 2020, a confirmed outbreak due to an H5N8 highly pathogenic avian influenza virus (HPAIV) occurred at an egg-hen farm in Kagawa prefecture (western Japan). This virus, A/chicken/Kagawa/11C/2020 (Kagawa11C2020), was the first HPAI poultry isolate in Japan in 2020 and had multiple basic amino acids—a motif conferring high pathogenicity to chickens—at the hemagglutinin cleavage site. Mortality of chickens was 100% through intravenous inoculation tests performed according to World Organization for Animal Health criteria. Phylogenetic analysis showed that the hemagglutinin of Kagawa11C2020 belongs to clade 2.3.4.4B of the H5 Goose/Guangdong lineage and clusters with H5N8 HPAIVs isolated from wild bird feces collected in Hokkaido (Japan) and Korea in October 2020. These H5N8 HPAIVs are closely related to H5N8 HPAIVs isolated in European countries during the winter of 2019–2020. Intranasal inoculation of chickens with 106 fifty-percent egg infectious doses of Kagawa11C2020 revealed that the 50% chicken lethal dose was 104.63 and the mean time to death was 134.4 h. All infected chickens demonstrated viral shedding beginning on 2 dpi—before clinical signs were observed. These results suggest that affected chickens could transmit Kagawa11C2020 to surrounding chickens in the absence of clinical signs for several days before they died.

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A reassortant highly pathogenic avian influenza H5N6 virus originating from the wildbird-origin H5N6 and the poultry H9N2/H7N9 viruses in Xinjiang, China

Medycyna Weterynaryjna ◽

10.21521/mw.6532 ◽

2021 ◽

Vol 77 (06) ◽

pp. 6532-2021

Author(s):

QIAN ZHANG ◽

XINDI MEI ◽

CHENG ZHANG ◽

FEI DU ◽

NANA CHANG ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Highly Pathogenic Avian Influenza ◽

Wild Birds ◽

Influenza Viruses ◽

Highly Pathogenic ◽

Pathogenic Avian Influenza ◽

Sequence Identity ◽

Pathogenic Avian Influenza Virus

The asian lineage of H5, H7, and H9 avian influenza viruses (AIVs) is the most prevalent in the world, and the co-existence of H5, H7, and H9 viruses provide an opportunity to generate some novel reassortants. Herein we report our isolation of two H5N6 virus strains (named XJ-H5N6) from domestic geese in live poultry markets (LPMs) in Urumqi during the winter of 2016-2017, and analysis of the viral genetic mutations, pathogenicity, reassortant, and origin. BLAST analysis revealed that the HA, NA, MP, NP, and NS of XJ-H5N6 had the highest sequence identity (98.5-99.5%) with those 5 genes from H5N6 highly pathogenic avian influenza virus (HPAIV) isolated from wild birds in Ningxia (NX-WB-H5N6); the viral PA and PB1 had the highest sequence identity (98.6% and 98.9%) with those 2 genes from HPAIV strain A/Environment/Chongqing/45373/2015 (H5N6) (CQ-EN-H5N6); while the viral PB2 had the highest sequence identity (99.0%) with this gene from low pathogenic avian influenza virus (LPAIV) strain A/environment/Jiangsu/01.20 TCCX004/2015 (H9N2). Except for the PB2, phylogenetic analysis showed that the other 7 viral genes were clustered together with NX-WB-H5N6 and CQ-EN-H5N6, while the viral PB2 was clustered together with the poultry H9N2/H7N9 viruses. The viral HA protein contained multiple basic amino acid residues (RRRKR/GL) at the cleavage site which represents HPAIV. Additionally, the viral multiple mutations could enhance the viral virulence and the capacity of cross-species transmission. Our data indicate that XJ-H5N6 has been generated by the reassortant of H5N6 HPAIV from wild birds in Ningxia and H9N2/H7N9 LPAIV in poultry. The results of this study may help us understand the viral adaptation and transmission patterns from wild birds to poultry.

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