An Investigation of Perinatal Hepatitis B Virus Infections Among a High Risk Population

Abstract

There was an increase in perinatal hepatitis B virus (HBV) infections in one Arkansas county that disproportionately affected Marshallese infants. 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). 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) <or=12 hours after birth (88% vs. 87%; P = 0.91). Approximately 57% (n = 32) of all infants born to HBsAg-positive women were tested for perinatal HBV infection. The proportion of Marshallese (17%) and non-Marshallese (13%) infants who tested positive for HBsAg at ages 9 to 25 months was similar (P = 0.78). Receiving HBIG >12 hours after birth was the only factor significantly associated with infection. 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.