Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Dec;14(1):2455601.
doi: 10.1080/22221751.2025.2455601. Epub 2025 Jan 31.

Emergence of a novel reassortant highly pathogenic avian influenza clade 2.3.4.4b A(H5N2) Virus, 2024

Rabeh El-Shesheny  1 , Mokhtar Gomaa  1 , Mohamed El Sayes  1 , Mina Nabil Kamel  1 , Ahmed El Taweel  1 , Omnia Kutkat  1 , Mohamed GabAllah  1 , Amany Elkhrsawy  1 , Hager Emam  1 , Yassmin Moatasim  1 , Ahmed Kandeil  1   2 , Pamela P McKenzie  2 , Richard J Webby  2 , Mohamed Ahmed Ali  1 , Ghazi Kayali  3
Affiliations

Emergence of a novel reassortant highly pathogenic avian influenza clade 2.3.4.4b A(H5N2) Virus, 2024

Rabeh El-Shesheny et al. Emerg Microbes Infect. 2025 Dec.

Abstract

Reassortant highly pathogenic avian influenza A(H5N2) clade 2.3.4.4.b viruses were detected from ducks and environmental samples in Egypt, June 2024. Genomic and phylogenetic analyses revealed a novel genotype produced by the reassortment of an A(H5N1) clade 2.3.3.4b virus with an A(H9N2) G1-like virus. Monitoring the spread of this virus is important.

Keywords: Egypt; Highly pathogenic avian influenza virus H5N2; reassortment; viruses; zoonotic influenza.

PubMed Disclaimer

Conflict of interest statement

No potential conflict of interest was reported by the authors.

Figures

Figure 1.
Figure 1.
Phylogenetic tree of novel highly pathogenic avian influenza A(H5N2) clade 2.3.4.4b viruses in Egypt, 2024. (A) HA segment and (B) Schematic representation of origin of virus isolates from Egypt. Bars represent 8 gene segments of avian influenza virus in the following order (top to bottom): polymerase basic 2, polymerase basic 1, polymerase acidic, hemagglutinin, nucleoprotein, neuraminidase, matrix, and nonstructural. Phylogenetic analysis was performed using the neighbour-joining algorithm with the Kimura two-parameter model. The reliability of phylogenetic inference at each branch node was estimated by the bootstrap method with 1000 replications. Evolutionary analyses were conducted using MEGA 7. A(H5N2) clade 2.3.4.4b viruses isolated in this study are shown in red.
See this image and copyright information in PMC

References

    1. El-Shesheny R, Moatasim Y, Mahmoud SH, et al. . Highly pathogenic avian influenza A(H5N1) virus clade 2.3.4.4b in wild birds and live bird markets, Egypt. Pathogens. 2022 Dec 26;12(1):36. - PMC - PubMed
    1. Kandeil A, El-Shesheny R, Maatouq AM, et al. . Genetic and antigenic evolution of H9N2 avian influenza viruses circulating in Egypt between 2011 and 2013. Arch Virol. 2014 Nov;159(11):2861–2876. - PMC - PubMed
    1. Naguib MM, Arafa AS, El-Kady MF, et al. . Evolutionary trajectories and diagnostic challenges of potentially zoonotic avian influenza viruses H5N1 and H9N2 co-circulating in Egypt. Infection, Genetics and Evolution: Journal of Molecular Epidemiology and Evolutionary Genetics in Infectious Diseases. 2015 Aug;34:278–291. - PubMed
    1. Kayali G, Kandeil A, El-Shesheny R, et al. . Avian influenza A(H5N1) virus in Egypt. Emerg Infect Dis. 2016 Mar;22(3):379–388. - PMC - PubMed
    1. Hassan KE, King J, El-Kady M, et al. . Novel reassortant highly pathogenic avian influenza A(H5N2) virus in broiler chickens, Egypt. Emerg Infect Dis. 2020 Jan;26(1):129–133. - PMC - PubMed

MeSH terms