Molecular Characterization of Highly Pathogenic Avian Influenza H5Nx in Upper Egypt during 2023 | ||
| Journal of Current Veterinary Research | ||
| Volume 7, Issue 2, October 2025, Pages 14-27 PDF (1.18 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jcvr.2025.462631 | ||
| Authors | ||
| Hayam Rabie Abu Talib; Ahmed S. Kamal; Alaa A. Gaballah; Mahmoud Ibrahim* | ||
| Abstract | ||
| The highly pathogenic avian influenza (HPAI) H5Nx viruses circulate worldwide causing high economic losses and infecting some species of mammals including humans. Epidemiological investigations for respiratory viruses of poultry in Upper Egypt are limited so, this study investigated them in 20 chicken farms in Assiut, Sohag, and Qena Governorates during 2023. Two farms from Assiut were positive for H5N1 (10%) while the other two farms from Sohag were positive for H5N8 (10%), while 4 farms were tested positive for H9N2 AIV (20%). Two HPAI H5N8 and H5N1 have been isolated, and HA gene was sequenced with PLREKRRKRGLF sequence in cleavage site indicating a virus of high pathogenicity. Three amino acids (aa) conserved mutations observed between H5N8 and H5N1 strains; T140A/S in antigenic site A, N189K in the antigenic site B, and N236D close to the receptor binding domain (RBD) compared to A/North shoveler/Egypt/MB-D-819OP/2016 H5N8 strain. Antigenically all strains tested from clade 2.3.4.4b including H5N1 or H5N8 subtypes were similar but antigenically different from H5N1 clade 2.2.1 virus. Therefore, using vaccines with seed strains from clade 2.3.4.4b is recommended to give a specific immune response and efficient protection and this would help in disease control and reduce the evolution of H5Nx viruses in Egypt. | ||
| Keywords | ||
| HPAI; LPAI; Egypt; H5N8; H5N1 | ||
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