National project on the prevention of mother-to-infant infection by hepatitis B virus in Japan.

In Japan, a nationwide prevention program against mother-to-infant infection by hepatitis B virus (HBV) started in 1985. This program consists of double screenings of pregnant women and prophylactic treatment to the infants born to both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive mothers. These infants are treated with two injections of hepatitis B immune globulin (HBIG) and at least three injections of plasma derived hepatitis B vaccine. We sent questionnaires about the numbers of each procedure or examination during nine months of investigation period to each local government in 1986 and 1987. 93.4% pregnant women had the chance to be examined for HBsAg, and the positive rate was 1.4 to 1.5%. The HBeAg positive rate in HBsAg positive was 23 to 26%. The HBsAg positive rate in neonates and in infants before two months were 3% and 2% respectively. Some problems may arise, because 27 to 30% of infants need the fourth vaccination in some restricted areas.