A 1:1 matched case-control study was conducted to identify risk factors for avian influenza subtype H9N2 infection on commercial poultry farms in 16 districts of Punjab, and 1 administrative unit of Pakistan. One hundred and thirty-three laboratory confirmed positive case farms were matched on the date of sample submission with 133 negative control farms. The association between a series of far...

Background and Aims: Influenza A virus subtype H9N2 have continued to circulate in domestic poultry farms in Asia since 1998. The virus circulates in live bird markets, missing link in epidemiology of avian influenza. Regarding previous studies on H9N2 viruses of Iran and having no data on this subject in Iranian live bird markets this study was conducted to analyze genetically hemagglutinin pr...

Background and Aims: Avian Influenza (AI) H9N2 subtype was first reported to infect turkeys in the United States in 1966 and has been panzootic in Eurasia. In Iran, the H9N2 virus was first isolated from broiler chickens in 1998 in Ghazvin province and it is the most prevalent subtype of influenza virus in poultry industry in Iran at the present time. Materials and Methods: In this study, we se...

Influenza A viruses of subtype H9N2 are wide spread among poultry and other mammalian species. Crossing the species barrier from poultry to human occurred in recent years creating a pandemic of H9N2 virus. It is known that the pathogenicity of H9N2 is lower than H5N1. Nonetheless, it is important to establish the molecular functions of H9N2 viral proteins. We studied mutations in the polymerase...

Avian influenza virus subtype H9N2 (H9N2) and Chlamydia psittaci (C. psittaci) are frequently isolated in chickens with respiratory disease. However, their roles in co-infection remain unclear. We tested the hypothesis that C. psittaci enhances H9N2 infection through suppression of host immunity. Thus, 10-day-old SPF chickens were inoculated intra-tracheally with a high or low virulence C. psit...

objectives the aim of this was to indentify the presence of a/h9n2 virus among different high risk occupational groups, in tehran and qazvin provinces in seasonal outbreak in iran. background in the last decade h9n2 avian influenza viruses had caused outbreaks in poultry in many parts of the world. this subtype could infect other animals such as human and pig. avian h9n2 virus has acquired rece...

background and aims: avian influenza (ai) h9n2 subtype was first reported to infect turkeys in the united states in 1966 and has been panzootic in europe and asia. the impact of avian influenza caused by h9n2 viruses in iran is now significantly more severe than in previous years. methods: sequence analysis and phylogenetic study of the complete coding region polymerase a (pa) gene of h9n2 subt...

conclusions after seven consecutive passages of both cell cultures, the h9n2 virus showed similar antigenicity, also no change on viral titer level and virus replication behavior in adaptation was found. the results highlighted the use of a549 cells for efficient virus isolation. results the influenza virus infectivity was not significant difference in these cells in the presence of trypsin. th...

Background and Aims: Avian Influenza (AI) H9N2 subtype was first reported to infect turkeys in the United States in 1966 and has been panzootic in Europe and Asia. The impact of avian influenza caused by H9N2 viruses in Iran is now significantly more severe than in previous years. Methods: Sequence analysis and phylogenetic study of the complete coding region Polymerase A (PA) gene of H9N2 subt...

BACKGROUND Influenza A subtype H9N2 is widespread and prevalent in poultry. It has repeatedly transmitted zoonotically to cause mild influenza-like illness in humans and is regarded as a potential pandemic candidate. In additon, the six internal genes of H7N9 and H10N8 viruses which caused infection in human in China as well as some of the highly pathogenic H5N1 strains are origined from H9N2. ...