CHARACTERIZATION OF H5N1 INFLUENZA VIRUSES ISOLATED FROM MIGRATORY BIRDS IN QINGHAI PROVINCE OF CHINA IN 2006

To determine the genetic origins of novel H3 avian influenza viruses of chickens and ducks in Korea, genetic characterization of H3 avian influenza viruses isolated from live poultry markets and migratory aquatic birds in South Korea during 2004–2006 was conducted. Phylogenetic analysis revealed that at least four novel genotypes of H3N2 and two genotypes of H3N6 avian influenza viruses were co-circulating in backyard poultry of Korea. The viruses were reassortants between H9N2 viruses of Korean chickens and unknown influenza viruses of migratory birds. Genetic comparison of H3 viruses from live bird markets with those from wild bird isolates revealed that certain gene segments of wild bird isolates are related closely to those of Korean group H9N2 viruses isolated from live poultry markets in 2003. Furthermore, animal-challenge studies demonstrated that the pathogenicity of certain avian H3 influenza viruses was altered due to reassortment, leading to H3 avian influenza viruses in Korea that can potentially expand their host range to include mammals. These studies emphasize the continuing need to monitor backyard poultry at live poultry markets to better understand interspecies transmission and the emergence of novel influenza viruses that have the potential to infect humans.

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Evolutionary Dynamics of Multiple Sublineages of H5N1 Influenza Viruses in Nigeria from 2006 to 2008

Journal of Virology ◽

10.1128/jvi.02385-09 ◽

2010 ◽

Vol 84 (7) ◽

pp. 3239-3247 ◽

Cited By ~ 31

Author(s):

Alice Fusaro ◽

Martha I. Nelson ◽

Tony Joannis ◽

Luigi Bertolotti ◽

Isabella Monne ◽

...

Keyword(s):

Evolutionary Dynamics ◽

Migratory Birds ◽

Influenza Viruses ◽

Multiple Introductions ◽

Poultry Products ◽

H5n1 Influenza ◽

H5n1 Avian Influenza ◽

Hpai H5n1 ◽

Commercial Poultry ◽

Source Populations

ABSTRACT Highly pathogenic A/H5N1 avian influenza (HPAI H5N1) viruses have seriously affected the Nigerian poultry industry since early 2006. Previous studies have identified multiple introductions of the virus into Nigeria and several reassortment events between cocirculating lineages. To determine the spatial, evolutionary, and population dynamics of the multiple H5N1 lineages cocirculating in Nigeria, we conducted a phylogenetic analysis of whole-genome sequences from 106 HPAI H5N1 viruses isolated between 2006 and 2008 and representing all 25 Nigerian states and the Federal Capital Territory (FCT) reporting outbreaks. We identified a major new subclade in Nigeria that is phylogenetically distinguishable from all previously identified sublineages, as well as two novel reassortment events. A detailed analysis of viral phylogeography identified two major source populations for the HPAI H5N1 virus in Nigeria, one in a major commercial poultry area (southwest region) and one in northern Nigeria, where contact between wild birds and backyard poultry is frequent. These findings suggested that migratory birds from Eastern Europe or Russia may serve an important role in the introduction of HPAI H5N1 viruses into Nigeria, although virus spread through the movement of poultry and poultry products cannot be excluded. Our study provides new insight into the genesis and evolution of H5N1 influenza viruses in Nigeria and has important implications for targeting surveillance efforts to rapidly identify the spread of the virus into and within Nigeria.

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Characterization of Avian H5N1 Influenza Viruses from Poultry in Hong Kong

Virology ◽

10.1006/viro.1998.9488 ◽

1998 ◽

Vol 252 (2) ◽

pp. 331-342 ◽

Cited By ~ 416

Author(s):

Kennedy F. Shortridge ◽

Nan Nan Zhou ◽

Yi Guan ◽

Peng Gao ◽

Toshihiro Ito ◽

...

Keyword(s):

Hong Kong ◽

Influenza Viruses ◽

H5n1 Influenza

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Characterization of H9 Subtype Influenza Viruses from the Ducks of Southern China: a Candidate for the Next Influenza Pandemic in Humans?

Journal of Virology ◽

10.1128/jvi.77.12.6988-6994.2003 ◽

2003 ◽

Vol 77 (12) ◽

pp. 6988-6994 ◽

Cited By ~ 186

Author(s):

K. S. Li ◽

K. M. Xu ◽

J. S. M. Peiris ◽

L. L. M. Poon ◽

K. Z. Yu ◽

...

Keyword(s):

Hong Kong ◽

Southern China ◽

Influenza Pandemic ◽

Influenza Viruses ◽

Current View ◽

Domestic Ducks ◽

H5n1 Influenza ◽

Pandemic Virus ◽

Influenza Outbreaks

ABSTRACT A current view of the emergence of pandemic influenza viruses envisages a gene flow from the aquatic avian reservoir to humans via reassortment in pigs, the hypothetical “mixing vessel.” Understanding arising from recent H5N1 influenza outbreaks in Hong Kong since 1997 and the isolation of avian H9N2 virus from humans raises alternative options for the emergence of a new pandemic virus. Here we report that H9N2 influenza viruses established in terrestrial poultry in southern China are transmitted back to domestic ducks, in which the viruses generate multiple reassortants. These novel H9N2 viruses are double or even triple reassortants that have amino acid signatures in their hemagglutinin, indicating their potential to directly infect humans. Some of them contain gene segments that are closely related to those of A/Hong Kong/156/97 (H5N1/97, H5N1) or A/Quail/Hong Kong/G1/97 (G1-like, H9N2). More importantly, some of their internal genes are closely related to those of novel H5N1 viruses isolated during the outbreak in Hong Kong in 2001. This study reveals a two-way transmission of influenza virus between terrestrial and aquatic birds that facilitates the generation of novel reassortant H9N2 influenza viruses. Such reassortants may directly or indirectly play a role in the emergence of the next pandemic virus.

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Genetic characterization of highly pathogenic avian influenza A (H5N8) virus isolated from domestic geese in Iraq, 2018

BMC Veterinary Research ◽

10.1186/s12917-021-02831-y ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Nahla Muhammad Saeed ◽

Peshnyar Muhammad Atta Rashid ◽

Hiewa Othman Dyary

Keyword(s):

Molecular Markers ◽

Influenza A ◽

Migratory Birds ◽

Mammalian Species ◽

Influenza Viruses ◽

Genetic Characteristics ◽

Ha Gene ◽

North Iraq ◽

Group B

Abstract Background Influenza viruses are a continuous threat to avian and mammalian species, causing epidemics and pandemics. After the circulation of H5N1 in 2006, 2015, and 2016 in Iraq, an H5N8 influenza virus emerged in domestic geese in Sulaymaniyah Province, Iraq. This study analyzed the genetic characteristics of the Iraqi H5N8 viruses. Results An HPAI virus subtype H5N8 was identified from domestic backyard geese in the Kurdistan Region, north Iraq. Phylogenic analyses of the hemagglutinin (HA) and neuraminidase (NA) genes indicated that Iraq H5N8 viruses belonged to clade 2.3.4.4 group B and clustered with isolates from Iran, Israel, and Belgium. Genetic analysis of the HA gene indicated molecular markers for avian-type receptors. Characterization of the NA gene showed that the virus had sensitive molecular markers for antiviral drugs. Conclusions This is the first study ever on H5N8 in Iraq, and it is crucial to understand the epidemiology of the viruses in Iraq and the Middle East. The results suggest a possible role of migratory birds in the introduction of HPAI subtype H5N8 into Iraq.

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Genetic Characterization of Novel H7Nx Low Pathogenic Avian Influenza Viruses from Wild Birds in South Korea during the Winter of 2020–2021

Viruses ◽

10.3390/v13112274 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2274

Author(s):

Yu-Na Lee ◽

Dong-Hun Lee ◽

Jung-Hoon Kwon ◽

Jae-In Shin ◽

Seo Yun Hong ◽

...

Keyword(s):

Avian Influenza ◽

South Korea ◽

Migratory Birds ◽

Wild Birds ◽

Influenza Viruses ◽

The Novel ◽

Zoonotic Infection ◽

Avian Influenza Viruses ◽

Constellation Analysis

Zoonotic infection with avian influenza viruses (AIVs) of subtype H7, such as H7N9 and H7N4, has raised concerns worldwide. During the winter of 2020–2021, five novel H7 low pathogenic AIVs (LPAIVs) containing different neuraminidase (NA) subtypes, including two H7N3, an H7N8, and two H7N9, were detected in wild bird feces in South Korea. Complete genome sequencing and phylogenetic analysis showed that the novel H7Nx AIVs were reassortants containing two gene segments (hemagglutinin (HA) and matrix) that were related to the zoonotic Jiangsu–Cambodian H7 viruses causing zoonotic infection and six gene segments originating from LPAIVs circulating in migratory birds in Eurasia. A genomic constellation analysis demonstrated that all H7 isolates contained a mix of gene segments from different viruses, indicating that multiple reassortment occurred. The well-known mammalian adaptive substitution (E627K and D701N) in PB2 was not detected in any of these isolates. The detection of multiple reassortant H7Nx AIVs in wild birds highlights the need for intensive surveillance in both wild birds and poultry in Eurasia.

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Molecular Characterization of Closely Related H6N2 Avian Influenza Viruses Isolated from Turkey, Egypt, and Uganda

Viruses ◽

10.3390/v13040607 ◽

2021 ◽

Vol 13 (4) ◽

pp. 607

Author(s):

Yavuz Mercan ◽

Gladys Atim ◽

Ahmed E. Kayed ◽

M. Ekin Azbazdar ◽

Ahmed Kandeil ◽

...

Keyword(s):

Avian Influenza ◽

Molecular Characterization ◽

Migratory Birds ◽

Virus Transmission ◽

Influenza Viruses ◽

East African ◽

Avian Influenza Viruses ◽

Geographical Regions ◽

Natural Hosts

Genetic analysis of circulating avian influenza viruses (AIVs) in wild birds at different geographical regions during the same period could improve our knowledge about virus transmission dynamics in natural hosts, virus evolution as well as zoonotic potential. Here, we report the genetic and molecular characterization of H6N2 influenza viruses isolated from migratory birds in Turkey, Egypt, and Uganda during 2017–2018. The Egyptian and Turkish isolates were genetically closer to each other than they were to the virus isolated from Uganda. Our results also suggest that multiple reassortment events were involved in the genesis of the isolated viruses. All viruses contained molecular markers previously associated with increased replication and/or pathogenicity in mammals. The results of this study indicate that H6N2 viruses carried by migratory birds on the West Asian/East African and Mediterranean/Black Sea flyways have the potential to transmit to mammals including humans. Additionally, adaptation markers in these viruses indicate the potential risk for poultry, which also increases the possibility of human exposure to these viruses.

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Genetic characterization of an H5N6 avian influenza virus with multiple origins from a chicken in southern China, October 2019

BMC Veterinary Research ◽

10.1186/s12917-021-02903-z ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Feng Wen ◽

Jing Yang ◽

Jinyue Guo ◽

Congying Wang ◽

Qing Cheng ◽

...

Keyword(s):

Avian Influenza ◽

Human Health ◽

Migratory Birds ◽

Southern China ◽

Influenza Viruses ◽

Nucleotide Sequencing ◽

Poultry Industry ◽

Avian Influenza Viruses ◽

Multiple Origins

Abstract Background Highly pathogenic avian influenza viruses (HPAIVs) of H5 subtype pose a great threat to the poultry industry and human health. In recent years, H5N6 subtype has rapidly replaced H5N1 as the most predominate HPAIV subtype circulating in domestic poultry in China. In this study, we describe the genetic and phylogenetic characteristics of a prevalent H5N6 strain in Guangdong, China. Results Nucleotide sequencing identified a H5N6 subtype HPAIV, designated as A/chicken/Dongguan/1101/2019 (DG/19), with a multibasic cleavage site in the hemagglutinin (HA). Phylogenetic analysis revealed DG/19 was a reassortant of H5N1, H5N2, H5N8, and H6N6 subtypes of avian influenza viruses. A number of mammalian adaptive markers such as D36N in the HA were identified. Conclusions Our results showed that HPAIV H5N6 strains still emerge in well-managed groups of chicken farms. Considering the increasing prevalence of H5N6 HPAIV, and the fact that H5N6 HPAIVs are well adapted to migratory birds, an enhanced surveillance for the East Asian-Australasian flyway should be undertaken to prevent potential threats to the poultry industry and human health.

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Characterization of human influenza A (H5N1) virus infection in mice: neuro-, pneumo- and adipotropic infection

Journal of General Virology ◽

10.1099/0022-1317-81-10-2503 ◽

2000 ◽

Vol 81 (10) ◽

pp. 2503-2510 ◽

Cited By ~ 54

Author(s):

Hidekazu Nishimura ◽

Shigeyuki Itamura ◽

Takuya Iwasaki ◽

Takeshi Kurata ◽

Masato Tashiro

Keyword(s):

Hong Kong ◽

Influenza A ◽

Degenerative Change ◽

Lethal Dose ◽

Virus Antigen ◽

Influenza Viruses ◽

Adipose Tissues ◽

H5n1 Influenza ◽

The Brain

Mice (ddY strain, 4 weeks old) were infected intranasally with the H5N1 influenza viruses A/Hong Kong/156/97 (HK156) and A/Hong Kong/483/97 (HK483) isolated from humans. HK156 and HK483 required 200 and 5 p.f.u. of virus, respectively, to give a 50% lethal dose to the mice when the volume of inoculum was set at 10 μl. Both viruses caused encephalitis and severe bronchopneumonia in infected mice. The severity of lung lesions caused by the viruses was essentially similar, whereas HK483 caused more extensive lesions in the brain than did HK156. This was supported by the results of virus titration of organ homogenates, which showed that the virus titres in brains of HK483-infected mice were more than 100-fold higher than those of HK156-infected mice, while those in lungs were almost equivalent. Both viruses were detected in homogenates of the heart, liver, spleen and kidney and blood of the infected mice. Virus antigen was detected by immunohistology in the heart and liver, albeit sporadically, but caused no degenerative change in these organs. The antigen was not detected in the thymus, spleen, pancreas, kidney or gastrointestinal tract. In contrast, virus antigen was found frequently in adipose tissues attached to those organs. The adipose tissues showed severe degenerative change and the virus titres in the tissues were high and comparable to those in lungs. Thus, infection of HK156 and HK483 in our mouse model was pneumo-, neuro- and adipotropic, but not pantropic. Furthermore, HK483 showed higher neurotropism than HK156, which may account for its higher lethality.

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