Molecular methods for the detection of avian influenza type A viruses

Two RT-PCR methods with primers aimed at NP and M genes for the detection of avian influenza virus (AIV) in allantoic fluids of SPF embryonated eggs as well as in tissues of SPF chickens infected experimentally are described. Both methods proved to be equally specific but RT-PCR aimed at M gene seemed to be more sensitive (10 EID50) than the second one (100 EID50). To detect AIV in chicken tissues, SPF chickens were inoculated intraocularly with 10 6 EID50 of A/African starling/England/983/79 reference strains (H7N1) and 5 d after inoculation. various tissue samples were aseptically collected, examined with PCR-based methods and subjected to virus isolation on SPF embryos. The results showed high concordance between the used methods, but some discrepancies were also noted.