Type Identification and Characteristic Analysis on Influenza Virus for 43 Strains

Objective\] To investigate the type characteristics of influenza virus of 43 strains in Fuzhou in 2002 Influenza viruses were isolated by MDCK and egg inoculation method The types were identified by the test of hemagglutination activity (HA) and hemagglutination inhibition (HI) 43 strains of influenza virus were isolated from 806 pharynx swab in which 41 strains were separated by MDCK method 21 strains were ”O” phase virus in 22 strains of Type A3 and the titer of HI test was over 1∶320 in which the titer of “02411” strain was 1∶640 4 strains were similar to “B/shanghai/20/2001” and 16 strains similar to “B/zhejiang/2/2001” in 20 strains of Type B and the titer of HI were ≥1∶640 \[Conclusion\] The main influenza virus is Type A3, then is Type B in Fuzhou in 2002 and the antigenicity of Type A3 varied a lot In Oct 2003, ”02411” strain of Type A3 (”A3/Fujian viruses strains/411/02”) is identified as representative strains by WHO for the component of influenza vaccine in the southern hemisphere in 2004