Isolation and analysis of influenza virus during 2007-2008 epidemic season in Tai’an city, Shandong province

Objective　To isolate the influenza viruses and analyze the influenza activity in 2007 to 2008 epidemic season in Taian city, Shandong province. Methods　Influenza viruses were isolated from the throat swabs collected from the influenza-like cases by Madin-Darby canine kidney (MDCK) cells and identified by hemagglutination inhibition (HAI) assay. Results　From October, 2007 to March, 2008, a total of 281 throat swab samples from 2 surveillance hospitals were tested, and 94 strains of influenza viruses were isolated with the positive rate of 33.45%. By subtyping, 51 strains of A (H3N2) virus, 1 strain of A (H1N1) virus, 39 strains of B /Yamagata lineage virus, and 3 strains of B/Victoria lineage virus were detected. Conclusion　During 2007 to 2008 influenza season, the predominant strains were A (H3N2) and B/Yamagata lineage viruses in Tai'an, and A (H1N1) and B/Victoria lineage viruses were also in circulation.