The need for more aggressive follow-up of children born to hepatitis B surface antigen-positive mothers: Lessons from the Louisiana perinatal hepatitis B immunization program

Background. Preventing perinatal transmission of hepatitis B virus (HBV) is an important part of strategies to prevent HBV-related disease. To help prevent perinatal transmission the Louisiana Office of Public Health began in 1990 a statewide program to track children of hepatitis B surface antigen (HBsAg)-positive mothers. We examined data from this program to evaluate the effectiveness of the program and to assess the value of serologic testing in the program. Methods. We examined vaccination and testing records for all children listed in the program database who were old enough to have been tested, according to program recommendations, as of July, 1993. Results. Of 426 children 269 (63%) had been completely vaccinated. Also of these 426 children 194 (46%) were tested for hepatitis B surface antibody (anti-HBs) and 163 (38%) were tested for HBsAg. Among tested children 6 (4%) were HB-sAg-positive and 22 (11%) were anti HBs-negative. Incompletely vaccinated children were more likely than completely vaccinated children to be HBsAg-positive (risk ratio, 7.9; 95% confidence interval, 1.5 to 41.2) and less likely to be positive for anti-HBs (risk ratio, 0.5, confidence interval, 0.3 to 0.7). Children tested greater than or equal to 18 months after the last vaccine dose were more likely than children tested earlier to be anti-HBs-negative (risk ratio, 0.8; 95% confidence interval, 0.7 to 1.1). Conclusions. Rates of vaccination completion and postvaccination serologic testing were low for children in this program. Even with these low vaccination rates, however, we estimate that the program prevented 74% of HBV infection and 87% of HBV carriage in this group of high risk children, suggesting that failure to vaccinate rather than vaccine failure was the major obstacle to prevention of perinatal HBV transmission. Serologic testing was useful in that it identified children with chronic HBV infection and children who may have needed additional doses of vaccine, but it should be performed <18 months after the last dose of vaccine. is given. More aggressive follow-up of these children for both vaccination and serologic testing is needed.