Abstract
BACKGROUND AND OBJECT: The risk of occult HBV infection (OBI) in children whose mothers are HBV carriers has received more widespread attention, but there were few reports to focus on the children with HBsAg-positive parents. In this study, we aimed to investigate the prevalence of OBI in immunized children with HBsAg-positive parents. METHODS: HBV-vaccinated Chinese hospitalized children with HBsAg-positive parents were analyzed in our investigation. Eligible subjects were tested using a standard nested PCR for all HBV genes, and analyzed by direct sequencing. RESULTS: There were 327 HBsAg-negative children included in the study out of about 9800 involved HBV-vaccinated hospitalized children. The positive rate of OBI was 3.1% (10/327) in the eligible children and 14.1% (46/327) with HBV DNA detectable. No significant differences were found between one and at least two regions positive groups (p > 0.05). The proportions of HBV DNA detectable in children with HBV father-carriers and mother-carriers were similar. The risk factors for HBV DNA-positive children could be male, anti-HBs levels, and anti-HBc positive. CONCLUSION: There are 3.1% of OBIs and 14.1% of suspected OBI in vaccinated children with HBsAg-positive parents. The potential risk of suspected OBI in children with HBsAg-positive father should not be ignored. Anti-HBc positivity may be a useful seromarker for suspected OBI screening in vaccinated children. To prevent HBV breakthrough infection, accurate and convenient method is needed to detect OBI timely and exhaustively.