Analysis on influenza monitoring results in Yunnan Province from 2002 to 2004

Objective This study was designed to rind out the antibody level for influenza among healthy people at the monitoring site through epidemic trend monitoring for influenza．Methods Tbe chick embryo and MDCK cell were used for separation of virus．And the isolated strain was typed and serum antibody measured through hemagglutination inhibition (HI) test，Resttlts in the recent three years，the influenza stains of A3 type and B type were prevalent among people in our province．And the total positive rate of all influenza strain antibodies among healthy people was 15.33％-99.33％．Conclusion Different types of Strains predominated alternatively，and the rise and fall of influenza antibody level among people conformed to the type of dominant strain