Mapping Genetic Markers Associated with Antigenicity and Host Range in H9N2 Influenza A Viruses Infecting Poultry in Pakistan.

The aim of the current study was to map the genetic diversity in the haemagglutinin (HA) glycoprotein of influenza A viruses (IAVs) of the H9N2 subtype. Twenty-five H9N2 IAVs were isolated from broiler chickens from March to July 2019. The HA gene was amplified, and phylogenetic analysis was performed to determine the evolutionary relationship.

Rate of Multiple Viral and Bacterial CoInfection(s) in Influenza A/H9N2-Infected Broiler Flocks.

Repeated cases of low pathogenic influenza A/H9N2 virus (IAV/H9N2) have been reported in commercial chickens since its emergence in 1998 in Pakistan. However, recently increased mortality and severe respiratory complications under field conditions have been noticed, suggesting concomitant influenza infections with respiratory viral and/or bacterial pathogens. Therefore, the present study aimed to investigate the presence of IAV/H9N2 coinfecting with multiple viral and bacterial pathogens in broiler chicken flocks.