Hepatitis B--potential of perinatal transmission in India.

To estimate the frequency of perinatal hepatitis B virus (HBV) infection, 850 pregnant females were tested for HBsAg and HBeAg using RPHA kits. Frequency of HBsAg positivity was 4.6% by RPHA and 6.34% by micro-ELISA. HBeAg was detected in 18% of the HBsAg positive pregnant females. Presuming a perinatal HBV infection rate of 90% amongst infants born to HBsAg and HBeAg positive pregnant females and 17% amongst infant born to HBsAg positive but HBeAg negative mothers, we estimated that 1.17% to 1.64% infants out of 24 million births occurring annually in this country would be infected with HBV. In other words every year 2.8 to 3.9 lakh infants are being infected by HBV perinatally, 90% of whom will eventually develop chronic HBV infection. Urgent control measures are necessary to circumvent this problem.