Hepatitis B Elimination in Children of Slovenian Origin Born in Slovenia After the Introduction of Preventive Strategies: the Results of a National Study

INTRODUCTION: In Slovenia national strategies to prevent hepatitis B virus (HBV) infection in children were introduced in the mid-nineties. The aim of the present study was to analyze the epidemiological characteristics of chronic hepatitis B infection in children in Slovenia after the introduction of mandatory HBV vaccination of children and mandatory screening of pregnant women for HBV surface antigen (HBsAg) with consecutive active and passive immunization of newborns of HBsAg-positive mothers. METHODS: Children from all regions of Slovenia whose blood samples tested positive for HBsAg at the national reference laboratory for viral hepatitis between January 1997 and December 2010 were included. Demographic, epidemiological and virological data were reviewed retrospectively. Statistical evaluation of the patients’ characteristics was performed and possible trends during the observation period determined. RESULTS: Among 52 HBsAg-positive children, there were 22 (42.3%) girls and 30 (57.7%) boys. Among 40 children tested for HBeAg, 17 were positive (42.5%). The most frequent risk factor for acquiring HBV infection was “presence of HBV infection within the family” (24/35; 68.8%). A significant association between the presence of HBeAg and a viral load of >20,000 IU/ml was found (p=0.001). The difference in the proportion of children of Slovenian origin born before 1994 and after was statistically significant (p=0.039). A statistically significant negative linear trend of the number of diagnosed children in the observed period was found (p=0.006). CONCLUSIONS: Prevention strategies adopted in the mid-nineties have resulted in the elimination of chronic hepatitis B in children of Slovenian origin born in Slovenia.