Use of Chromatographic Immune Assay for the Quantitative Detection of H9N2 Avian Influenza Virus


Between January 2004 and February 2005,Twenty cases of Avian Influenza Virus infected broilers and layers were diagnosed.The symptoms included anorexia, ruffled feathers and swollen head with cyanotic comb and wattles, congestion of the shanks.The necropsied birds showed general congestion especially in breast region, there was accumulation of mucous, fibrinous and caseated materials in trachea which in some cases was severally congested and hemorrhage were seen in proventriculus. The virus was isolated by inoculating nine –day-old embryonated eggs via the allantoic sac . The embryos died within 3-4 days and the allantoic fluid contained heamagglutination activity to a titer 128. The virus neutralized by H9N2 hyperimmuneserum in heamagglutination inhibition but not neutralized by ND virus antibody.Agar gel immuno diffusion test were performed on antiserum with specific hyper immune serum against H9N2 virus, in positive results demonstrated the presence of virus in allantoic fluid. A rapid avian influenza virus antigen test kit which is a chromatographic immunoassay for the quantitative detection of the virus were used. The positive results demonstrated by the presence of two purple color bands Negative results were noticed with Newcastle disease virus and H5 influenza virus test kits.