Hepatitis B virus seroprevalence, associated factors and vaccination status among children and adolescents in Black Sea Region of Turkey

The aim of this study was to determine the prevalence of hepatitis B virus (HBV) serologic markers in children and adolescents and the impact of the vaccination program over the last 9 years. The laboratory records of 10175 children were retrospectively evaluated in children who visited a tertiary hospital, between January 2009 and December 2017. The overall prevalence of HBsAg and anti-HBs were 2.0%, and 69.3%, respectively. HBsAg prevalence increased with age. The carriage rate was more prevalent  in rural areas and in cases born before the country-wide vaccination program. HBeAg positive cases were more common than anti-HBe Ag positive cases (67.6% vs. 32.4%). Anti-HBs was on a rising trend in the 1-23-month age group while it tended to decline after 2-6 years’ age group. There was a decrease in the prevalence of HBsAg in children due to ongoing vaccination efforts but the prevalence of HBsAg was still high during adolescence. The rates of anti-HBs positivity were lower in those living in rural areas and those born before the vaccination program.  Anti-HBs rates were decreasing as age progressed, but this decline was probably due to a natural reduction in anti-HBs concentration in successfully vaccinated individuals.