Immuno-prophylaxis of babies borne to hepatitis B carrier mothers
K Tse, SLY Siu, KT Yip, SM Chan, TL Que, WYS Lui, PS Chan
Department of Paediatrics and Adolescent Medicine, Tuen Mun Hospital, Tsing Chung Koon Road, Tuen Mun, Hong Kong
OBJECTIVES. To examine the efficacy of current hepatitis B immuno-prophylaxis and estimate the prevalence of S-mutant infections among local newborn babies.
DESIGN. Prospective study.
SETTING. Regional hospital, Hong Kong.
PATIENTS. A total of 137 newborn babies delivered between the period of November 2000 and 30 June 2001 inclusive, whose mothers were chronic hepatitis B surface antigen carriers.
RESULTS. Of the 121 infants who were followed up for 12 months, three were found to be chronic hepatitis B virus carriers, giving a vertical transmission rate of 2.5%. One (0.8%) was suspected to be infected by the S-mutant. All the three hepatitis B virus carrier babies were born to mothers with hepatitis B e antigen, but none to the eight mothers suspected to have S-mutants. Of 119 (98.3%) infants who developed hepatitis B surface antibody upon follow-up at 12 months, 35 were found to have hepatitis B e antigen at birth. All were born to hepatitis B e antigen;ndash;positive mothers. Only three of the 35 babies were found to be hepatitis B virus carriers. Most babies lost the hepatitis B e antigen by 6 months of age; only the infected babies had the antigen persisting at 1 year of age. The non-infected infants' hepatitis B e antigen is likely transplacental.
CONCLUSIONS. Our hepatitis B virus prophylaxis programme was effective at preventing perinatal infection and the non-infected infants' hepatitis B e antigen was likely transplacental.
Hong Kong Med J 2006;12:368-74
Key words: Hepatitis B e antigens; Hepatitis B surface
antigens; Hepatitis B vaccines; Infant, newborn