The methods for detection and study of influenza viruses, antibodies to them in Russia

Session III – Trushakova, Svetlana V., YI Applicant, Poster Only

Title of Contribution: The methods for detection and study of influenza viruses, antibodies to them in Russia.
Author(s): Trushakova S.V., Ivanova V.T., *Yatsyshina S.B., Oskerko T.A., Shevchenko E.S., Burtseva E.I.
Affiliation(s): D.I.Ivanovsky Research Institute of Virology RAMS, * Central Research Institute of Epidemiology of the Russian Health Ministry.
Abstract:
The influenza A and B viruses cause the epidemics among people every year. Russian commercial PCR test-systems (Real-time PCR and electrophoresis) were developed for monitoring of influenza viruses based on different fragments of influenza internal genes (NP or M1, NS). The electrophoresis system Narvak based on conserved fragment NP gene of influenza A virus was developed for bird viruses and manufactured in D.I.Ivanovsky Research Institute of Virology RAMS. The two Real-time PCR systems AmpliSens “Influenza virus A/H5N1” and “Influenza virus A/B” based on conserved fragments of M1 and NS genes were developed in Central Research Institute of Epidemiology of the Russian health ministry. All systems have been checked with 20 reference strains influenza A/H1N1, A/H3N2 and B viruses isolated in 1977-2007 and some epidemic strains (n=23) with known antigenic structure from influenza virus collections of the Influenza Ecology and Epidemiology Center (IEEC). It was established that all systems could be used for virus detection in samples to determine aetiological agents of epidemics in Russia. The nasal swabs (n=62) collected in period 2003-2008 were analyzed with the test-system Narvak. The percent of PCR results and virus isolation coincidence was 70%. The nasal swabs (n=29) and (n=74) analyzed with two systems AmpliSens showed the coincidence 100% and 80% correspondingly. It is established all these commercial systems could be used for detection human influenza A and B viruses in influenza surveillance. We took part in development of new test-systems AmpliSens “Influenza virus A/H1N1” and “Influenza virus A/H3N2” contained conserved fragments of hemagglutinin H1 and H3 genes. The testing with the known reference and epidemic strains of influenza A/H1N1, A/H3N2 viruses (n=15) isolated in 1977-2008 from virus collection of IEEC has been shown 100% coincidence with HI tests. Now these systems are in the stage of licensing. The HI tests were used for antigenic analysis of strains isolated in two last seasons 2006-2007, 2007-2008 in Russia. It was shown that the epidemics were caused by co-circulation of influenza A/H1N1, A/H3N2 and B viruses. The peculiarity of these seasons was the intensive variety of HA of influenza A/H1N1 viruses. The evolution of viruses occurred in direction for A/H1N1 viruses–A/New Calidonia/20/99, A/Solomon Islands/3/06, A/Brisbane/59/07; for A/H3N2 viruses–A/Wisconsin/67/05, А/Brisbane/10/07. Influenza B viruses belonged to B/Victoria/2/87-lineage in 2006-2007; B/Yamagata/16/88-lineage in 2007-2008. The HI tests of donor sera collected during these two seasons (n=424) in Moscow region have revealed the increase of the antibody levels to modern strains of influenza viruses А/H1N1, A/H3N2 and B to the end of epidemic seasons. So, the data of human population immunity confirmed the virological data. The studies were carried out in cooperation with CDC&P, Atlanta, USA. This work was supported in part ISTC grant #3070.