Maternal-child hepatitis B virus transmission in Singapore.

A study of maternal-infant transmission of hepatitis B virus (HBV) was conducted in Singapore between June 1980 and June 1982. HBsAg carrier rate was highest among Chinese (6.2%) followed by Malay (2.3%) and Indian (0.6%) mothers. The presence of HBeAg in maternal sera correlated well with high titre HBsAg (p = 7.34 X 10(-5)). Overall HBV transmission occurred in 27/56 (48.2%) infants from carrier mothers. The majority of the transmission was perinatal. There was a very strong correlation between transmission and HBeAg status of the mother (p = 1.85 X 10(-9); odds ratio = 68.44) and to a lesser extent with high titre HBsAg (p = 0.002; odds ratio = 6.38). A strong negative correlation was seen between transmission and anti-HBeAg (p = 8.19 X 10(-7); odds ratio = 0.04). At one year 19 (70.4%) infants were still HBsAg positive while seven (25.9%) lost the antigenemia and acquired anti-HBsAg and one developed HBsAg after one year. It could be calculated that perinatal HBV transmission contributed about 18% to the total pool of HBsAg positive infants of one year of age.