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Literature detail

Biological characterisation of the emerged highly pathogenic avian influenza (HPAI) A(H7N9) viruses in humans, in mainland China, 2016 to 2017.

Wenfei Zhu1,2 Jianfang Zhou1,2 Zi Li1,2 Lei Yang1 Xiyan Li1 Weijuan Huang1 Sumei Zou1 Wenbing Chen1 Hejiang Wei1 Jing Tang1 Liqi Liu1 Jie Dong1 Dayan Wang1 Yuelong Shu1
Affiliations 2 institutions
  1. National Institute for Viral Disease Control and Prevention, China Centers for Disease Control and Prevention, Key Laboratory for Medical Virology, National Health and Family Planning Commission, Beijing, China.
  2. These authors contributed equally to this work.
PMID 28537546 2017 Euro Surveill eng ppublish
PubMed DOI Browse context

Article

Publication summary

With no or low virulence in poultry, avian influenza A(H7N9) virus has caused severe infections in humans. In the current fifth epidemic wave, a highly pathogenic avian influenza (HPAI) H7N9 virus emerged. The insertion of four amino acids (KRTA) at the haemagglutinin (HA) cleavage site enabled trypsin-independent infectivity of this virus. Although maintaining dual receptor-binding preference, its HA antigenicity was distinct from low-pathogenic avian influenza A(H7N9). The neuraminidase substitution R292K conferred a multidrug resistance phenotype.

Antigenic analysis Drug sensitivity Highly pathogenic H7N9 viruses HPAI Receptor binding profile Disease Outbreaks Animals Antiviral Agents China Female Hemagglutinin Glycoproteins, Influenza Virus Humans Influenza A Virus, H7N9 Subtype Influenza in Birds Influenza, Human Neuraminidase Poultry Viral Load

Structured evidence records

Evidence records

5 total
Molecular Adaptation 3 records
Molecular Adaptation Extraction confidence 0.95
Key finding

Insertion of KRTA at the HA cleavage site allowed the H7N9 virus to replicate independently of trypsin, marking a molecular adaptation linked to increased pathogenicity.

Virus
IAV H7N9
Host
Not specified
Location
Not specified
Supporting text

The insertion of four amino acids (KRTA) at the haemagglutinin (HA) cleavage site enabled trypsin-independent infectivity of this virus.

Genes or proteins
HA
Mutations
KRTA insertion
Mechanism types
cell_entry; pathogenicity
Molecular Adaptation Extraction confidence 0.95
Key finding

The H7N9 virus retained dual receptor-binding preference but exhibited altered HA antigenicity compared with low-pathogenic strains.

Virus
IAV H7N9
Host
Not specified
Location
Not specified
Supporting text

Although maintaining dual receptor-binding preference, its HA antigenicity was distinct from low-pathogenic avian influenza A(H7N9).

Genes or proteins
HA
Receptors
dual receptor-binding preference
Mechanism types
receptor_binding; immune_escape; pathogenicity
Molecular Adaptation Extraction confidence 0.95
Key finding

The neuraminidase R292K substitution in H7N9 conferred multidrug resistance, representing a molecular adaptation influencing antiviral susceptibility.

Virus
IAV H7N9
Host
Not specified
Location
Not specified
Supporting text

The neuraminidase substitution R292K conferred a multidrug resistance phenotype.

Genes or proteins
neuraminidase
Mutations
R292K
Mechanism types
immune_escape; pathogenicity
Receptor Usage 1 records
Receptor Usage Extraction confidence 0.90
Key finding

The highly pathogenic H7N9 virus retained a dual receptor-binding preference similar to low-pathogenic strains, indicating conserved receptor usage properties.

Virus
IAV H7N9
Location
Not specified
Supporting text

Although maintaining dual receptor-binding preference, its HA antigenicity was distinct from low-pathogenic avian influenza A(H7N9).

Receptors
dual receptor-binding preference
Spillover Event 1 records
Spillover Event Extraction confidence 0.90
Key finding

Avian influenza A(H7N9) viruses transmitted from avian sources infected humans in mainland China between 2016 and 2017.

Virus
IAV H7N9
Location
China mainland China, China
Supporting text

Avian influenza A(H7N9) virus has caused severe infections in humans.

Study design
outbreak investigation
Transmission direction
animal-to-human
Geographic raw
mainland China
Country inferred
China