Impact of HBV Vaccination on Prevalence of Hepatitis B Virus Infection Among Volunteer Blood Donors in Tehran-Iran

Abstract

Background: Hepatitis B (HB) vaccination is the most effective measure for preventing hepatitis B virus (HBV) infection and its consequences. HB vaccination has been a part of the Expanded Program on Immunization (EPI) of Iran since 1993. To extend HBV immunization, mass HBV vaccination was planned for adolescents born during 1989-1992. Objectives: The aim of the present study was to assess the prevalence of HBV infection in Tehran blood donors after implementing national HB vaccination program. Patients and Methods: Prevalence of HBV infection was determined in all of Tehran blood donors born during 1989-1993 as cases and the ones born during 1986-1988 as controls. All the participants were recruited after medical interviews. Serum samples taken from the participants as well as other blood donors were tested according to the IBTO standards for hepatitis B surface antigen (HBsAg). Initially, positive samples were tested with appropriate confirmation methods. Statistical comparisons were performed using chi-square test. Prevalence estimates were age-adjusted by the direct method for comparisons across subgroups. Results: The prevalence of HBV infection was 57/100 000, 350/100 000, and 265/100 000 among accepted blood donors born during 1989-1993 (cases), 1986-1988 (nonconcurrent controls), and 1989-1993 (concurrent controls), respectively. The prevalence of HCV infection in the same group of blood donors was 28/100 000, 38/100 000, and 31/100 000, respectively. Conclusions: HBV prevalence was significantly lower among blood donors born during 1989-1993, which reflected the positive impact of EPI program and extended mass vaccination against HBV.