The infant and hepatitis B virus infection.

HBV has been shown to be responsible for a broad spectrum of disease in infants although most are asymptomatic carriers with mild transaminase elevation and unresolved hepatitis on liver biopsy. Maternal-infant transmission is responsible for most infections. Blood product infusion should become less significant. Acute maternal hepatitis in the perinatal period results in asymptomatic infant infections at rates far exceeding transmission from asymptomatic carrier mothers. Carrier mothers with the e-antigen or HBV-associated DNA polymerase transmit infection more readily than do carrier mothers without these HBV markers. The presence of maternal anti-e may be protective. Intrapartum and postpartum transmission occurs more often than transplacental infection. For this reason attempts at prophylaxis with immune serum globulin administered in the newborn period should be further evaluated.