ANALYSIS ON ISOLATION OF INFLUENZA VIRUS IN NANSHAN DISTRICT OF SHENZHEN FROM 2005 TO 2007

[Objective] To understand the variation of influenza virus and its epidemic rules in Nanshan District of Shenzhen City in past three years for further prevention and control of influenza.[Methods] Madin-Darby Canine Kidney(MDCK) cell was used to isolate and identify the influenza virus strains.[Results] In 2005,a total of 64 influenza viruses strains were isolated,of which 9 strains were influenza A(H1N1) virus,44 influenza A(H3N2) virus and 11 influenza B virus;in 2006,48 influenza viruses strains were isolated,of which 18 strains were influenza A(H2N2) virus,2 influenza A(H3N2) virus and 28 influenza B virus;in 2007,69 in fluenza viruses strains were isolated,of which 2 strains were influenza A(H2N2) virus,57 influenza A(H3N2) virus and 10 influenza B virus.The positive rate of isolation over that three years was 13.3%,12.0% and 22.6% respectively.[Conclusion] During the 3-year period of influenza pathogenic surveillance,although no new mutated strain has been found,the prevalence of influenza virus has changed its type every year.The influenza A(H3N2) virus is the dominant strain prevailed in 2005,influenza A H3N2 and B(Victoria) viruses are the dominant strains prevailed in 2006,and the influenza A(H3N2) virus is the dominant strain prevailed again in 2007.