Abstract
Human infections with H7N9 avian influenza virus were first reported in the early spring of 2013, in the Yangtze-delta region of China. This virus subsequently caused five successive epidemic waves from 2013 to 2018 with highest reported cases in the last wave making this strain the most successful zoonosis influenza virus in humans in recent decades. No H7N9 human infections have been reported since 2019, probably because of the extensive vaccination of poultry. Although zoonoses of H7N9 and other subtypes of avian influenza viral infections remain rare, the virus could acquire sufficient mammalian adaptive mutations to allow it to cause a future influenza pandemic. Here, we summarize the main findings on viral and host factors affecting the interspecies transmission of the H7N9 avian influenza virus.
Highlights
The influenza A virus (IAV) has been detected in a wide range of host species, making it a prototype for emerging viruses with pandemic potential
No human isolates with dual mutations in PB2 at positions 627 and 701 have been reported, these mutations have been discovered in a ferret transmission model and have been found to confer enhanced fitness in mammalian cells and mice [33].Another subunit of the polymerase basic protein PB1 has a potentially biologically important I368V mutation [34,35], which is associated with acquired transmissibility of the H5N1 avian influenza virus among ferrets [36].The PB1 gene encodes the full-length PB1-F2 protein of approximately 89 amino acids
Previous studies have shown that host genetic factors are important in the pathogenesis of, or susceptibility to, influenza viral infections [41].Single-nucleotide variants (SNVs) of several genes, including TMPRSS2, IFITM3,TLR3, and CD55, are associated with the severity of human infections with H7N9 viruses [42,43,44] (Table 1)
Summary
The influenza A virus (IAV) has been detected in a wide range of host species, making it a prototype for emerging viruses with pandemic potential. The cumulative number of cases of human infection with different avian influenza virus subtypes since the first reported year or the year of a well-known epidemic (H7N7).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
