Investigation on Common Influenza Viruses Affecting Chickens and Ducks in Egypt

Ali, Ahmed A. H.; Mansour, Shimaa M.G.; Hefny, Sozun M.; Sultan, Serageldeen

doi:10.21608/scvmj.2023.310673

Investigation on Common Influenza Viruses Affecting Chickens and Ducks in Egypt

Document Type : Review Article

Authors

¹ Department of Virology, Faculty of Veterinary Medicine, 44511, Zagazig University, Zagazig, Egypt

² Department of Microbiology, Virology Division, Faculty of South Valley University, Qena 83523, Egypt

10.21608/scvmj.2023.310673

Abstract

Influenza viruses (IVs) consist of Alphainfluenzavirus (Influenzavirus A), Betainfluenzavirus (Influenzavirus B), Gammainfluenzavirus (Influenzavirus C), Deltainfluenzavirus (Influenzavirus D), Isavirus, Mykissvirus, Sardinovirus, Quarajavirus and Thogotovirus genera in the family Orthomyxoviridae. Owing to their surface glycoproteins, hemagglutinin (HA), and neuraminidase (NA), diversity in poultry influenza A virus is further categorized into 16 HA (H1–H16) and 9 NA (N1–N9) subtypes. However, these glycoprotein subtypes are 20 HA and 11 NA in mammals. The pathogenicity of avian IVs (AIVs) in birds exhibits a high pathogenic (HP) form of AIV which causes severe deaths among birds or a low pathogenic (LP) form of AIV where birds look normal. The H5 subtype is a considerable risk to the human population even if it is a low pathogenic one. The co-circulation of HPAIV and LPAIV subtypes among different avian species in Egypt detrimental effect on the national economy. H5N1, H5N2, H5N8, and H9N2 viruses will be addressed in this review as the predominant subtypes in Egypt. The contribution of migratory wild birds in maintaining the endemicity of AIV LPAIV or HPAIV among domesticated poultry will also be clarified.

Keywords