New H5N1 Influenza Virus Sublineages in Egypt and Their Human Infection Potential
Author Information
Author(s): Watanabe Yohei, Ibrahim Madiha S., Ellakany Hany F., Kawashita Norihito, Mizuike Rika, Hiramatsu Hiroaki, Sriwilaijaroen Nogluk, Takagi Tatsuya, Suzuki Yasuo, Ikuta Kazuyoshi
Primary Institution: Department of Virology, Research Institute for Microbial Diseases (BIKEN), Osaka University, Osaka, Japan
Hypothesis
Did recent H5N1 influenza viruses in Egypt acquire mutations that enhance their ability to bind to human-type receptors?
Conclusion
The emergence of new H5N1 sublineages with enhanced receptor binding affinity for human-type sialic acids is linked to the increase in human infections in Egypt.
Supporting Evidence
- Phylogenetic analysis showed clustering of recent human isolates into new H5 sublineages.
- Mutations in the hemagglutinin (HA) gene were identified that enhance binding to human-type receptors.
- Recombinant viruses with specific mutations showed increased infectivity in human airway epithelial cells.
- Enhanced virulence was observed in mice infected with mutant viruses compared to the parental strain.
Takeaway
Some bird viruses in Egypt changed to better attach to human cells, which might explain why more people got sick.
Methodology
Phylogenetic analysis of H5N1 viruses and receptor binding assays were conducted to assess binding affinity to human-type receptors.
Limitations
The study does not conclusively determine the pandemic potential of the H5N1 viruses in Egypt.
Digital Object Identifier (DOI)
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