AU - Vasfi Marandi, Mehdi AU - Bozorgmehri Fard, Mohammad Hassan TI - Isolation of H9N2 Subtype of Avian Influenza Viruses during an Outbreak in Chickens in Iran PT - JOURNAL ARTICLE TA - انستیتو-پاستور-ایران JN - انستیتو-پاستور-ایران VO - 6 VI - 1 IP - 1 4099 - http://ibj.pasteur.ac.ir/article-1-570-en.html 4100 - http://ibj.pasteur.ac.ir/article-1-570-en.pdf SO - انستیتو-پاستور-ایران 1 AB  - Avian influenza is an important disease of poultry with the potential to cause major epidemics resulting in significant economic losses. The presence of avian influenza viruses (AIV) in chickens in Iran has not been previously reported. An avian influenza outbreak in broiler, layer and breeder farms occurred during a very hot summer in July 1998. Three AIV isolates designated as 101, 102 and 103 were isolated from lung, tracheal cloacal samples of layer, breeder and broiler chickens, in embryonated chicken eggs. The presence of AIV in allantoic fluid cells was confirmed by indirect immunofluorescence assay using a monoclonal antibody against type A nucleoprotein. The viruses were further classified as H9N2 subtype in hemagglutination inhibition and neuraminidase inhibition tests using 15 hemagglutinin and 9 neuraminidase subtype specific antisera. The pathogenicity of AIV isolates was carried out in 4-6-wk-old chickens. No birds died within 10 days after inoculation of infectious allantoic fluids. Therefore, the representative Iranian layer, breeder and broiler AIV strains were classified as non-highly pathogenic avian influenza viruses pathotype. Isolation of the same subtype and pathotype of AIV from different flocks suggested that the H9N2 AIV subtype is a common pathogen involved in poultry industry respiratory disease outbreak. CP - IRAN IN - LG - eng PB - انستیتو-پاستور-ایران PG - 13 PT - Full Length/Original Article YR - 2002