ارزيابي مقايسه اي روش هاي ايمونوهيستو شيميايي در تشخيص بيماري آنفلوآنزاي طيور

Comparative and evaluation of immunohistochemical methods for detection of avian Influenza disease.

The immunohistochemical techniques related to clinical diagnosis tests, has been used for rapid diagnosis of avian viral diseases by the poultry laboratory diagnosticians. Avian influenza (AI) is an important viral disease of poultry worldwide and causes by avian influenza virus (AIV). This disease caused high economic losses in Iranian poultry industry. In this study, the indirect immunoflurescence (IIF) and indirect immunoperoxidase (IIP) assays were compared with the standard virus isolation procedure on tissue samples prepared from chickens experimentally infected as well as clinical specimens. These techniques were optimized in broiler chickens inoculated with local H9N2 AI viruses. The trachea, lung and kidney tissue samples from experimentally infected and clinical samples were embedded into OCT (Optimum Cutting Temperature) and put primarily at -196 ¢?C and then after at -70 ¢?C in order to prepare frozen tissue sections. The IIF and IIP assays carried out on frozen tissue sections. The sensitivity and specificity values of IIF and IIP assays analyzed vis a vis virus isolation were respectively 86, 81 % and 93, 81 % for clinical specimens. The positive and negative predictive values of IIF and IIP assays were 76, 89 % and 77, 94 % respectively. There was a substaintial agreement between virus isolation and IIF, IIP assays for knowing of infection in chickens (by Kappa statistic 92 and 95% respectively). The application of IIP assay for diagnosis of H9N2 subtype antigens in frozen tissue sections is for the first time in Iran. According of results, for immunohistochemical monitoring of chicken flocks, the IIP assay particularly in kidney tissue samples has been recommended.