scholarly journals Human infections with novel reassortant H5N6 avian influenza viruses in China

2017 ◽  
Vol 6 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Ye Zhang ◽  
Minmei Chen ◽  
Yiwei Huang ◽  
Wenfei Zhu ◽  
Lei Yang ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Human Infections

scholarly journals Molecular analysis of avian H7 influenza viruses circulating in Eurasia in 1999–2005: detection of multiple reassortant virus genotypes

2008 ◽  
Vol 89 (1) ◽  
pp. 48-59 ◽  
Author(s):  
Laura Campitelli ◽  
Angela Di Martino ◽  
Domenico Spagnolo ◽  
Gavin J. D. Smith ◽  
Livia Di Trani ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Southern China ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Phylogenetic Groups ◽  
Entire Genome ◽  
Domestic Poultry ◽  
Virus Genotypes ◽  
In The Wild ◽  
Human Infections

Avian influenza infections by high and low pathogenicity H7 influenza viruses have caused several outbreaks in European poultry in recent years, also resulting in human infections. Although in some cases the source of H7 strains from domestic poultry was shown to be the viruses circulating in the wild bird reservoir, a thorough characterization of the entire genome of H7 viruses from both wild and domestic Eurasian birds, and their evolutionary relationships, has not been conducted. In our study, we have analysed low pathogenicity H7 influenza strains isolated from wild and domestic ducks in Italy and southern China and compared them with those from reared terrestrial poultry such as chicken and turkey. Phylogenetic analysis demonstrated that the H7 haemagglutinin genes were all closely related to each other, whereas the remaining genes could be divided into two or more phylogenetic groups. Almost each year different H7 reassortant viruses were identified and in at least two different years more than one H7 genotype co-circulated. A recent precursor in wild waterfowl was identified for most of the gene segments of terrestrial poultry viruses. Our data suggest that reassortment allows avian influenza viruses, in their natural reservoir, to increase their genetic diversity. In turn this might help avian influenza viruses colonize a wider range of hosts, including domestic poultry.

Double mutations in the H9N2 avian influenza virus PB2 gene act cooperatively to increase viral host adaptation and replication for human infections

2021 ◽  
Vol 102 (6) ◽  
Author(s):  
Emad Mohamed Elgendy ◽  
Yasuha Arai ◽  
Norihito Kawashita ◽  
Ayana Isobe ◽  
Tomo Daidoji ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Polymerase Activity ◽  
Host Adaptation ◽  
Influenza Viruses ◽  
Human Adaptation ◽  
Avian Influenza Viruses ◽  
Human Virus ◽  
H9n2 Avian Influenza Virus ◽  
Human Infections ◽  
Virus Isolates

Avian H9N2 influenza viruses in East Asia are genetically diversified and multiple genotypes (A-W) have been established in poultry. Genotype S strains are currently the most prevalent strains, have caused many human infections and pose a public health threat. In this study, human adaptation mutations in the PB2 polymerase in genotype S strains were identified by database screening. Several PB2 double mutations were identified that acted cooperatively to produce higher genotype S virus polymerase activity and replication in human cells than in avian cells and to increase viral growth and virulence in mice. These mutations were chronologically and phylogenetically clustered in a new group within genotype S viruses. Most of the relevant human virus isolates carry the PB2-A588V mutation together with another PB2 mutation (i.e. K526R, E627V or E627K), indicating a host adaptation advantage for these double mutations. The prevalence of PB2 double mutations in human H9N2 virus isolates has also been found in genetically related human H7N9 and H10N8 viruses. These results suggested that PB2 double mutations in viruses in the field acted cooperatively to increase human adaptation of the currently prevalent H9N2 genotype S strains. This may have contributed to the recent surge of H9N2 infections and may be applicable to the human adaptation of several other avian influenza viruses. Our study provides a better understanding of the human adaptation pathways of genetically related H9N2, H7N9 and H10N8 viruses in nature.

Human infections with avian influenza viruses in mainland China: A particular risk for southeastern China

2017 ◽  
Vol 75 (3) ◽  
pp. 274-276 ◽  
Author(s):  
Bin Xiang ◽  
Wenxian Zhu ◽  
Renrong You ◽  
Libin Chen ◽  
Yaling Li ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Mainland China ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Southeastern China ◽  
Human Infections

scholarly journals Zoonotic Potential of Currently Circulating Avian Influenza Viruses

2020 ◽  
Vol 39 (1) ◽  
pp. 8-14
Author(s):  
Vladimir Savić
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Human Infection ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Influenza Pandemics ◽  
Human Infections ◽  
Virus Adaptation ◽  
Efficient Transmission

Over the past and the current centuries, human influenza pandemics have been attributable to viruses with an avian ancestry. Birds are the main source of influenza A viruses and harbour a variety of antigenic subtypes. Certain avian influenza viruses are capable for cross-species transmission including human infections. Although sustained intrehuman transmission of such viruses has not been documented so far, each human infection with avian influenza viruses provides chances for the virus adaptation towards efficient transmission within human population. Here are reviewed currently circulating avian influenza viruses that are of major significance for public health.

scholarly journals Avian influenza viruses in humans: lessons from past outbreaks

2019 ◽  
Vol 132 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Yao-Tsun Li ◽  
Martin Linster ◽  
Ian H Mendenhall ◽  
Yvonne C F Su ◽  
Gavin J D Smith
Keyword(s):  
Risk Factors ◽  
Avian Influenza ◽  
Virus Transmission ◽  
Human Infection ◽  
Influenza Viruses ◽  
Avian Species ◽  
Avian Influenza Viruses ◽  
Virus Surveillance ◽  
Changing Patterns ◽  
Human Infections

Abstract Background Human infections with avian influenza viruses (AIV) represent a persistent public health threat. The principal risk factor governing human infection with AIV is from direct contact with infected poultry and is primarily observed in Asia and Egypt where live-bird markets are common. Areas of agreement Changing patterns of virus transmission and a lack of obvious disease manifestations in avian species hampers early detection and efficient control of potentially zoonotic AIV. Areas of controversy Despite extensive studies on biological and environmental risk factors, the exact conditions required for cross-species transmission from avian species to humans remain largely unknown. Growing points The development of a universal (‘across-subtype’) influenza vaccine and effective antiviral therapeutics are a priority. Areas timely for developing research Sustained virus surveillance and collection of ecological and physiological parameters from birds in different environments is required to better understand influenza virus ecology and identify risk factors for human infection.

Serological reports of human infections of H7 and H9 avian influenza viruses in northern China

2009 ◽  
Vol 44 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Na Jia ◽  
Sake J. de Vlas ◽  
Yun-Xi Liu ◽  
Jiu-Song Zhang ◽  
Lin Zhan ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Northern China ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Human Infections
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