FGBI "ARRIAH" took part in international comparative tests to detect RNA of avian influenza and Newcastle disease viruses

In the period from April to August 2021, the Reference Laboratory for Viral Diseases of Birds of the Federal State Budgetary Institution "Federal Center for Animal Health" subordinate to ROSSELKHOZNADZOR took part in comparative tests organized by the Reference Laboratory of the European Union and the World Organization for Animal HEALTH for avian influenza and Newcastle disease (Istituto Zooprofilattico Sperimentale delle Venezie, IZSVe), Padova, Italy.

The test program included three diagnostic panels designed respectively to test samples using molecular methods (viral genome detection), virological (viral antigen detection) and serological (antibody detection) methods.

For molecular studies, the Reference Laboratory for Avian Viral Diseases received 15 encrypted freeze-dried inactivated isolates of avian influenza virus, avian paramyxovirus serotype 1, and samples that did not contain RNA of these viruses. The diagnostic panel consisted of eight avian influenza viruses isolated in Europe, Asia and Africa, five avian paramyxoviruses serotype 1 of European and American origin, and two negative samples.

As part of the molecular round, it was necessary to identify the RNA of avian influenza virus and avian paramyxovirus serotype 1 and identify subtypes H5, H7, N1, N2, N6, N8 of avian influenza viruses by RT-PCR, as well as characterize the potential virulence of identified avian influenza viruses of subtypes H5, H7 and avian paramyxovirus serotype 1 by cutting site sequencing.

As a result of the studies, RNA of avian influenza virus and avian paramyxovirus serotype 1 was correctly identified in all samples. Subtypes H5, H7, N1, N2, N6, N8 of avian influenza viruses were correctly identified and the potential virulence of viruses was correctly characterized.

During the virological round, participating laboratories were asked to test a panel of samples for the presence of a hemagglutinating agent with the determination of the titer in the hemagglutination test (HAT) and to further differentiate subtypes of AIV A/H5, A/H7, A/H9 and avian paramyxovirus serotype 1 using the test inhibition of hemagglutination (RTGA).

The serological round included testing encrypted samples of chicken blood sera for the presence of antibodies to AIV type A in the enzyme-linked immunosorbent assay (ELISA) reaction and to AIV subtypes H5, H7, H9 and APMV-1 in RTGA.

Samples for virology were 12 lyophilized samples, one of which was negative (PBS solution), 9 samples contained AIV antigens of Eurasian and African origin of subtypes H5N1, H5N2, H5N8, H5N5, H7N3, H7N7, H9N2 and 2 samples - APMV serotypes 1 and four.

The serological panel consisted of 10 samples of chicken blood sera taken at different times after immunization with APMV strains of serotypes 6 and 1 and AIV subtypes H5N1, H5N2, H5N5, H7N1, H9N2, as well as two negative samples.

Virological and serological studies were carried out in accordance with the Guidelines for the identification of avian influenza and Newcastle disease viruses in the hemagglutination inhibition reaction developed at the Federal State Budgetary Institution "ARRIAH". RTGA was performed using reference antigens and blood sera, as well as commercial kits of our own production for the detection of antibodies to AIV subtypes H5 and H9. For the detection of antibodies to AIV type A, a kit based on an indirect ELISA variant manufactured by the Federal State Budgetary Institution "ARRIAH" was used.

According to the final report of the provider, during the qualification check, the Reference Laboratory for Viral Diseases of Birds of the Federal State Budgetary Institution “ARRIAH” showed 100% convergence of the research results with the characteristics of the samples provided in the panels of each round.

Thus, the competence of FGBI “ARRIAH” in diagnosing especially dangerous and economically significant infectious diseases of birds was confirmed.

Press service of the FGBI "ARRIAH"