Jenni Laidman
March 26, 2012 — A greater percentage of infants at risk for hepatitis B are being successfully vaccinated against the virus, but almost half of all at-risk infants slip through the healthcare system unnoticed. This puts them at risk for chronic liver disease and premature death, according to an article published online March 26 in Pediatrics.
Despite a 33% increase in the number of infants at risk for hepatitis B (from 19,208 in 1994 to 25,600 in 2008; P < .001) the percentage of infants managed for hepatitis B risk increased even more (from 40.8% to 50.5%; P < .001) in those years.
Emily A. Smith, MPH, from the Division of Viral Hepatitis, National Center for HIV, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, and colleagues examined data from 1994 to 2008 to determine the success of the National Perinatal Hepatitis B Prevention Program (PHBPP), established in 1990 by the CDC to decrease perinatal hepatitis B virus (HBV) transmission.
Although CDC guidelines call for hepatitis B (HepB) vaccination before hospital discharge for all newborns, infants born to mothers who test positive for the hepatitis B surface antigen (HBsAG) are to receive HepB, as well as hepatitis B immune globulin (HBIG), within 12 hours of birth, followed by 2 to 3 more HepB doses during infancy, with a goal of 90% series completion by 6 to 8 months of age. PHBPP protocol calls for these at-risk infants to be tested for the infection after the vaccination series is complete.
At-risk infants who fail to complete the vaccine series or who delay completion have a significantly higher risk for chronic HBV. In a study of 426 children at risk for HBV, incomplete vaccination increased risk for chronic infection almost 8-fold. Another study showed that receiving HBIG more than 12 hours after birth was associated with increased risk for HBV infection among at-risk infants.
The new analysis covered 49 states (excluding Alaska), as well as Chicago, Illinois; Houston, Texas; New York City; Philadelphia, Pennsylvania; San Antonio, Texas; and Washington, DC. "The PHBPP achieved substantial progress in preventing perinatal hepatitis B virus infection in the United States," the authors note.
Among the case-managed infants, 94.4% received HepB and HBIG within a day of birth, and a smaller proportion of children completed the vaccine series within a year, falling from 86.0% to 77.7% (P = .004). However, testing for HBV increased among children who completed the vaccination series, rising from 25.1% to 56.0% (P < .001). This testing showed a decline in chronic HBV infections, from 2.1% in 1999 to 0.8% in 2008 (P = .001).
However, the authors acknowledge, "Significant gaps remain in identifying HBsAG-positive pregnant women, and completing management and assessment of their infants to ensure prevention of perinatal hepatitis B virus transformation."
Children born to mothers with the hepatitis B surface antigen have a 90% risk of developing chronic hepatitis, which could lead to liver failure or liver cancer. However, proper prophylaxis prevents 85% to 95% of infections.
Although fewer infants were lost to follow-up in 2008 (13.0%) than in 2004 (26.4%), the difference was not significant (P = .126) The most common reason for lack of follow-up was failure to locate the child, at 33.1%, followed by "moved out of country," at 24.4%. Family refusal was a growing reason children did not complete testing, rising from 10.8% in 2005 to 17.9% in 2008 (P = .020). The authors termed this "problematic."
Even with timely vaccines, risks remain for some portion of at-risk children. An estimated 1% to 10% of infants born to hepatitis-positive mothers develop chronic or breakthrough hepatitis infection. Breakthrough infection is strongly associated with the mother's viral load, with transmission rates as high as 32% for mothers with HBV DNA concentrations greater than 108 copies/mL.
The authors have disclosed no relevant financial relationships.
Pediatrics. 2012;129:609-616.
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