Seroepidemiology of Hepatitis B Virus Infection in Istanbul: A 20-year Survey

Objective: Turkey is an intermediate endemic country for hepatitis B virus (HBV) infection, with the prevalence rates showing regional differences. The aim of this study was to determine the recent prevalence of HBV infection among adults in Istanbul and to evaluate the impact of national vaccination program that started in 1998. Materials and Methods: Data of three healthcare centers from 3 different districts in Istanbul between 1995 and 2015 were obtained. HBV status of the participants was evaluated according to their hepatitis B surface antigen (HBsAg) and anti-HBs results. The change in HBV prevalence was evaluated by dividing the time included in the study into three periods: 1995-2002, 2003-2009 and 2010-2015. Statistical comparison between groups studied in each period was performed. To evaluate the impact of vaccination, the patients of 15-17 years of age were compared with the rest of the last study group. Results: Totally, 26001 adult patients were included in the study. HBsAg and anti-HBs tested positive in 4.24% and 16.81% of patients, respectively. When the 20 years included in the study were divided into three periods and each studied separately, the positive results for HBsAg decreased from 5.34% to 4.8% and 3.08%, and positive anti-HBs results increased from 14.24% to 15.45% and 19.57%, the difference between the groups being statistically significant (p<0.001). In vaccinated group (n=287), no one tested positive for HBsAg and 30.3% of patients tested positive for anti-HBs, being statistically different from the rest of the group (p<0.001). Conclusion: Despite the positive effects of vaccination, chronic HB remains a serious health problem.