Epidemiology, Genetic Characterization, and Pathogenesis of Avian Influenza H5N8 Viruses Circulating in Northern and Southern Parts of Egypt, 2017-2019

Mohamed Tarek; Mahmoud M Naguib; Abdel-Sattar Arafa; Laila A Tantawy; Karim M Selim; Shaimaa Talaat; Hesham A Sultan

doi:10.3390/ani11082208

Epidemiology, Genetic Characterization, and Pathogenesis of Avian Influenza H5N8 Viruses Circulating in Northern and Southern Parts of Egypt, 2017-2019

Animals (Basel). 2021 Jul 26;11(8):2208. doi: 10.3390/ani11082208.

Authors

Mohamed Tarek¹, Mahmoud M Naguib^{1

2}, Abdel-Sattar Arafa¹, Laila A Tantawy³, Karim M Selim¹, Shaimaa Talaat⁴, Hesham A Sultan⁴

Affiliations

¹ Reference Laboratory for Veterinary Quality Control on Poultry Production, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt.
² Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75237 Uppsala, Sweden.
³ Department of Poultry Disease, Animal Health Research Institute, Agriculture Research Center, Giza 12618, Egypt.
⁴ Department of Birds and Rabbits Medicine, University of Sadat City, Sadat 32511, Egypt.

Abstract

Highly pathogenic avian influenza (HPAI) viruses of subtype H5N8 continue to circulate, causing huge economic losses and serious impact on poultry production worldwide. Recently, HPAIV H5N8 has been spreading rapidly, and a large number of HPAI H5N8 outbreaks have been reported in Eurasia 2020-2021. In this study, we conducted an epidemiological survey of HPAI H5N8 virus at different geographical locations in Egypt from 2017 to 2019. This was followed by genetic and pathogenic studies. Our findings highlight the wide spread of HPAI H5N8 viruses in Egypt, including in 22 governorates. The genetic analyses of the hemagglutinin (HA) and neuraminidase (NA) gene segments emphasized a phylogenetic relatedness between the Egyptian HPAI H5N8 viruses and viruses of clade 2.3.4.4b recently isolated in Europe. These findings suggest that a potential back transmission of Egyptian HPAI H5N8 virus has occurred from domestic poultry in Egypt to migratory wild birds, followed by further spread to different countries. This highlights the importance of continuous epidemiological and genetic studies of AIVs at the domestic-wild bird interface.

Keywords: Egypt; influenza; pathogenicity; phylogenetic relatedness; poultry.