Influenza surveillance in Russia conducted by Center of Influenza Ecology and Epidemiology

The Center of Influenza Ecology and Epidemiology (IEEC, Moscow) has shown the cocirculation of influenza A/H1N1, A/H3N2 and B viruses in humans during the 2002-2003 season. All strains were isolated in MDCK system, but A/H1N1 viruses still had the propensity to propagate in embryonated eggs. The epidemic A/H1N1 strains were related to the reference strain A/New Caledonia/20/99. The population of A/H3N2 strains included A/Moscow/10/99, A/Panama/2007/99 and a new reference strain A/Fujian/411/02-like. Reemergence of influenza B/Victoria/2/87 lineage viruses absent in Russia for more than 10 years were discovered. Hemagglutinin (HA) of influenza B strains was related to that of B/long Kong/22/01; neuraminidase (NA) was more related to that of either B/Victoria/2/87 or B/Yamagata/16/88-like viruses. Serological data confirmed the circulation of all isolated strains. Different sensitivities of influenza A and B viruses to treatment by proteolytic enzyme bromelain were revealed; the most sensitive was B virus, and less sensitive were A/H3N2 and A/H1N1 viruses. Specific activities of the two bromelain preparations used were tested in relation to the high specific chromogenic substrate for thiol proteinase assay (L-pyroglutamyl-Lphenylalanyl-L-alanine-p-nitroanilide). (C) 2004 Elsevier B.V. All rights reserved.