Seroprevalence of HBV in immigrant pregnant women and coverage of HBIG vaccine for neonates born to chronically infected immigrant mothers in Hsin-Chu County, Taiwan.

This study was carried out to assess the prevalence of HBsAg positivity and coverage rate of antenatal HBV screening among immigrant women. In addition, the extent of administration of HBIG plus HB vaccine #1 to neonates born to chronically infected (HBeAg-positive/HBsAg-positive) mothers was assessed. All pregnant women residing in Hsin-Chu County, Taiwan and giving birth during 2004-2006 were recruited. Among all 16926 cases, the prevalence of HBsAg positivity according to their ethnicities was Mainland Chinese, 11.0% (68/616); Indonesian, 3.5% (15/426); Vietnamese, 7.4% (42/568); aboriginal Taiwanese, 20.6% (109/530); and non-aboriginal Taiwanese 11.5% (1536/13368). Among the HBsAg carriers, the prevalence of HBeAg positivity was Mainland Chinese, 52.9% (36/68); Indonesian, 53.3% (8/15); Vietnamese, 45.2% (19/42); aboriginal Taiwanese, 47.7% (52/109); and non-aboriginal Taiwanese, 26.8% (411/1534). With non-aboriginal Taiwanese as the reference category, results of multiple logistic regression revealed the healthy immigrant phenomenon in the HBsAg carriage state among pregnant women from Indonesia (OR 0.30; CI 95%: 0.18-0.50) and Vietnam (OR 0.68; CI 95%: 0.49-0.93). On the contrary, among chronically infected mothers, Mainland Chinese showed the highest risk for HBeAg positivity (OR 2.79; CI 95%: 1.7-4.58). More efforts should be made to improve HBV infection among aboriginal Taiwanese pregnant women who were more vulnerable to HBsAg positivity (OR 2.15; CI 95%: 1.72-2.68) and HBeAg positivity (OR 1.93; CI 95%: 1.28-2.90). Age was another independent predictor for HBsAg positivity (OR 1.02; CI 95%: 1.01-1.03) and for HBeAg positivity among chronically infected mothers (OR 0.93; CI 95%: 0.91-0.96). The coverage rates of antenatal HBV screening and HBIG plus HB vaccine #1 showed no difference among these multiple ethnic subgroups. In 2006, the overall coverage rate of antenatal HBV screening was 98.7% (5546/5639), with the individual rate being Mainland Chinese, 100% (267/267); Indonesian, 97.2% (106/109); Vietnamese, 99.5% (201/202); aboriginal Taiwanese, 97.0% (196/202); and non-aboriginal Taiwanese, 99.8% (4776/4785). The administration rate of HBIG plus HB vaccine #1 was 100% for all ethnic subgroups.