Molecular characterization of h9n2 avian influenza viruses isolated from commercial broiler chickens in Egypt during 2014-2015

Abstract EN

Avian influenza virus H9N2 is a panzootic pathogen that affects poultry causing mild to moderate respiratory distress but has been associated with high morbidity and considerable mortality.

In this study, one hundred and twenty cloacal and tracheal swabs and organs (trachea, lung and spleen) were collected from broiler chicken flocks in 8 Egyptian governorates from summer 2014 to spring 2015.

Results of RT-PCR revealed that 36 flocks were positive out of 120 flocks for H9N2 (30%) of which 24 infected with H9 only (66.7%) and 12 co-infected with H5N1 (19.4), NDV (11.1%) or IBV (8.3%).

Seasonal distribution of positive flocks was as follow: 0.8% in summer of 2014, 5.8% in autumn of 2014, 19.2% in winter of 2014 and 4.1% in spring of 2015.

Sequencing of HA gene and phylogenetic analysis of 7 selected H9N2 isolates representative of different governorates indicated that all isolates belong to G1-like lineage and are closely related to other Middle East H9N2 isolates.