Continuing evolution of H9 influenza viruses in Korean poultry

Abstract

We analyzed the evolution of H9 influenza viruses isolated from Korean chicken farms from 2002 to 2004. Korean H9 viruses formed two antigenically distinct groups: those isolated from 1996 to mid-2003, and those isolated from late 2003 through 2004. Most of the 2004 isolates showed greater cross-reactivity with the second group than with the first group. Phylogenetic analysis of the 12 viruses studied revealed three genotypes of H9N2 viruses and showed that reassortment had occurred. One isolate, Ck/Kor/164/04, belonged to the H9N8 subtype. Its HA and PB1 genes were similar to those of the H9N2 viruses, but its other genes were closely related to H3N8 viruses. This report is the first (to our knowledge) of H9N8 infection in this host. The pathogenicity of the early isolates altered due to antigenic drift and reassortment, leading to H9 avian influenza viruses in Korea that potentially can expand their host range to mammalians.

Evaluation of the effect of simultaneous infection with E. coli O2 and H9N2 influenza virus on inflammatory factors in broiler chickens

“…26 Elevation in human cytokines was observed after infection with H1N1 influenza virus. 27 The first stage of infection with swine influenza does not lead to interferon production. Increase in γ-interferon is observed 14 days post inoculation.…”

Highly Pathogenic Avian Influenza Virus (H5N1) in Domestic Poultry and Relationship with Migratory Birds, South Korea

“…Two subtype H5N1 strains were isolated in embryonated eggs that had been inoculated with fecal specimens obtained from migratory bird habitats by Chungbuk National University and Chungnam National University. Viral genes were sequenced and analyzed as described (9). The full-length sequences for each segment were used in phylogenetic analyses.…”

Vaccine Efficacy of Inactivated, Chimeric Hemagglutinin H9/H5N2 Avian Influenza Virus and Its Suitability for the Marker Vaccine Strategy

“…Of the numerous influenza virus subtypes, LPAI H9N2 viruses have been circulating in multiple avian species in Eurasia, resulting in great economic losses to the poultry industry due to decreased egg production and moderate to high mortality rates (5,7). In addition, H9N2 influenza viruses have become panzootic in Eurasia during the past decade and have been isolated from terrestrial poultry worldwide.…”