RESUMEN
The epidemic upsurge of influenza morbidity in the 2006-2007 season in Russia was caused by the active circulation of influenza A(H1N1), A(H3N2) and B viruses. The Center for Ecology and Epidemiology of Influenza studied 259 epidemic strains; All the strains were isolated on MDCK cell cultures. Influenza A(H1N1) viruses (n = 101) were antigenic variants of the references A/New Caledonia/20/99 and A/Solomon Islands/3/06. Influenza A(H3N2) viruses (n = 98) were antigenic variants of the references A/California/7/07 and A/Wisconsin/67/05. Twenty four influenza B virus strains were drift variants of the reference BI Shanghai/361/02 - lineage B/Yamagata/16188 and 36 were related to A/Malaysia/2506/05 - lineage B/Victoria/2/87). All the isolated strains actively interacted with human erythrocytes of the blood groups 0(I) and A(II) and very slightly with chicken ones. Twenty-two (48%) A(H1N1) strains and 19 (35%) A(H3N2) strains which were resistant to rimantafine were revealed. Studies of the donor sera collected in Moscow and the Moscow Region, the Jewish Autonomous Region, and Primorye revealed antibodies to today's strains; the level of antibodies in the preepidemic period depended on the region and strain. A study of changes in antibody formation in different periods of an epidemic process showed a rise in antibodies mainly to influenza A and B virus strains circulating in this period.
Asunto(s)
Anticuerpos Antivirales/sangre , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/inmunología , Virus de la Influenza B/inmunología , Gripe Humana/epidemiología , Gripe Humana/inmunología , Adulto , Animales , Antígenos Virales/genética , Antígenos Virales/inmunología , Antivirales/farmacología , Perros , Flujo Genético , Hemaglutinación , Humanos , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/efectos de los fármacos , Subtipo H3N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza B/efectos de los fármacos , Virus de la Influenza B/genética , Virus de la Influenza B/aislamiento & purificación , Gripe Humana/virología , Epidemiología Molecular , Rimantadina/farmacología , Federación de Rusia/epidemiología , Estudios Seroepidemiológicos , Adulto JovenRESUMEN
Investigations indicated that the epidemic upsurge of influenza morbidity in the 2005-2006 season in Russia was caused by the active circulation of influenza viruses A and B. The Center for Ecology and Epidemiology of Influenza, D. I. Ivanovsky Institute of Virology, Russian Academy of Medical Sciences, studied 182 epidemic strains. A hundred and thirteen influenza viruses A(H3N2) were similar to the reference A/California/07/2004 or were its antigenic variants. Thirteen influenza virus A(H1N1) strains that were antigenic variants of the reference A/New Caledonia/20/99 were isolated in sporadic cases. Influenza viruses B were similar to B/Malaysia/2506/2004--lineage B/Victoria/2/87). All the strains were isolated in the MDCK cell culture. Comparative study of the sensitivity of the chicken embryo (CE) and MDCK isolation system to the 1999-2006 epidemic strains showed that CE tropism was least pronounced in influenza viruses A(H3N2). Analysis of the 2002-2006 strains demonstrated that influenza viruses A reacted actively with human erythrocytes of the blood groups 0(I) and A(II) and very slightly with chicken ones. Eighty-five influenza virus A(H3N2) strains from the 2005-2006 epidemic season were investigated for rimantadine susceptibility. The frequency of rimantadine-resistant influenza virus A(H3N2) strains was 38.0%. Studies of 79 paired sera from patients revealed a rise of antibodies to influenza viruses A(H3N2) and B in 25.9-33.3 and 20.7-23.8% of cases, respectively. There was an increase in antibodies to influenza viruses A and B in the sera collected from donors in Moscow and its region in September 2005 to June 2006.