An investigation of perinatal hepatitis B virus infections among a high risk population: the delivery hospital as a safety net.

BACKGROUND: There was an increase in perinatal hepatitis B virus (HBV) infections in one Arkansas county that disproportionately affected Marshallese infants. METHODS: An estimated 6000 to 10,000 Marshallese, from the Pacific island nation of the Marshall Islands where HBV is highly endemic, live in one Arkansas county. We conducted a retrospective review of hospital and health department records from 2003 to 2005 in that county. We compared maternal screening for hepatitis B surface antigen (HBsAg) between Marshallese and non-Marshallese. We also reviewed birth and immunization records for infants born to HBsAg-positive mothers to evaluate postexposure prophylaxis (PEP). RESULTS: Ten percent (n = 41) of Marshallese births and 0.1% (n = 15) of non-Marshallese births were to HBsAg-positive women. Among those born to HBsAg-positive women, Marshallese and non-Marshallese infants were equally likely to receive PEP with hepatitis B vaccine (98% vs. 100%; P[r] = 0.98) and hepatitis B immune globulin (HBIG) 12 hours after birth was the only factor significantly associated with infection. CONCLUSIONS: Although HBV infection was more prevalent among Marshallese compared with non-Marshallese women, there were no differences in infant receipt of PEP and perinatal HBV infection. Delivery hospitals in this county had standing orders to administer hepatitis B vaccine to all newborns, which likely provided a safety net to prevent perinatal HBV transmission in this high-risk population.