Seroprvalence of hepatitis B virus among primary and high school students in Songjiang district of Shanghai municipality

Objective To examine changes in serum markers of hepatitis B virus (HBV) infection among students in primary and high schools in Songjiang district of Shanghai municipality 23 years after the inclusion of HBV vaccine in the nationwide Expanded Program of Immunization.Methods A cluster sampling survey with questionnaires and blood collection was done among 2 280 students in primary and high schools in Songjiang district.All serum samples were detected for HBV markers with enzyme-linked immunosorbent assay (ELISA).Results The ages of the 2 280 students surveyed ranged between 6 and 20 years.The overall prevalence of hepatitis B surface antigen (HBsAg) was 0.57% (13/2 280),with a lower prevalence of 0.33% (5/1 503) among the students with registered residence in Shanghai municipality than that of 1.03% (8/777) among the students without registered local residence.The overall prevalence of hepatitis B surface antibody (HBsAb) and hepatitis B core antibody (HBcAb) were 26.67% and 9.39%,respectively.The prevalence of HBsAb decreased first and then increased with the increment of age of the students,with the lowest prevalence rate of 15.7% among the students aged 17 years.Conclusion The prevalence of HBV has been reduced significantly among primary and high school students in Shanghai municipality.