Occult hepatitis B infection in children born to HBeAg-positive women confers a low long-term risk for HBsAg-positive infection.

ABSTRACT

PURPOSE: Mother-to-child transmission (MTCT) has been the main cause of chronic hepatitis B virus (HBV) infection, particularly in East Asia. Hepatitis B immunoglobulin (HBIG) and vaccination given directly after birth effectively prevents hepatitis B surface antigen (HBsAg)-positive (overt) HBV infection, but occult hepatitis B infection (OBI) may develop despite adequate prophylaxis. The aim of this study was to investigate the long-term outcome in children born to mothers with very high HBV DNA levels with special focus on children discovered in early childhood with OBI. METHODS: One-year and long-term outcome regarding overt and occult HBV infection were analysed in 66 children born to hepatitis B e antigen (HBeAg)-positive mothers, and were compared with one-year outcome in 69 children born to HBeAg-negative mothers. The children were born between 1998 and 2018. RESULTS: Six children born to HBeAg-positive mothers developed overt chronic HBV infection, in two cases after normal pregnancies and despite HBIG and vaccination, but never when nucleotide analogue treatment was given during pregnancy. OBI with HBV DNA detected in serum in the absence of surface antigen (HBsAg) was observed in four children at the age of 1 year. One of them was transiently HBsAg-positive at the age of 7 years. At long-term follow-up, six children had overt chronic infection, one had OBI and six had previous OBI or positive anti-HBc suggesting resolved unidentified infections. CONCLUSION: The results indicate that children born to mothers with high HBV DNA levels have approximately 10% risk to develop OBI despite antiviral treatment, vaccination and HBIG, but that such OBI confers a minimal long-term risk for overt infection, at least in immunocompetent children.