Analysis on the positive rate of HBsAg and anti-HBs level among students of a voluntary school in Zhengzhou City

Objective This study aimed To understand the positive rate of HBsAg and anti-HBs level among students of a voluntary school in Zhengzhou City in recent years after widespread inoculation of hepatitis B vaccine(HBV)．Methods A seroimmunity test(HBsAg and anti—HBs) was conducted for 465 students aged 5 to 15 years，who were newly enrolled in a Voluntary Little Harvard Bilingual School in Zhengzhou City from 2003 to 2004．Results The positive rate of HBsAg was O.4％(2/465)，which was greatly lower than that of 1992，and no positive case was found in the group aged 0 tO 6 years from 2003 to 2004．The positive rate of anti—HBs was 58.5％(272/465)．Which was significantly higher than that obmined from the investigation in Henan Province in 1992．Conclusion The positive rate of anti-HBs decreased with increase of age，while that of HBsAg increased with age，which showed the importance of strengthening vaccination