A retrospective serological survey of hepatitis B virus infection in Northeast China.

Though universal hepatitis B vaccination of infants has significantly reduced HBsAg prevalence in children, the number of most adults who have been infected with HBV remains steady. Extra care and resources should be provided to HBV-infected middle-aged males to stop the progression of chronic hepatitis B, and HBsAg positive females of childbearing age to block vertical HBV transmission.