Infection with hepatitis B virus in infancy A longitudinal study of 8 cases

SUMMARY Eight infants who developed HBsAg aged between 1 and 5 months were identified in the greater Copenhagen area during the period 1970-76. 7 had acquired the infection from their mothers and one had received a HB,Ag-positive blood infusion. 3 infants had a transient infection lasting 2 to 8 months while the remaining cases developed persistent antigenaemia with evidence of minor liver dysfunction during a follow-up of one to 6 years. HBeAg was persistently present in 4 of 5 infants, indicating infectivity in these patients. Prematurity or administration of specific immuno-globulin at delivery apparently did not affect the course of infection. Infection with hepatitis B virus is a rare cause of the hepatitis syndrome in infancy (Mowat et al., 1976; Danks et al., 1977). However vertical transmission from an infectious mother to her newborn infant has been recognised as an important mechanism for the maintenance and dissemination of hepatitis B in many areas (Mazzur and Blumberg, 1974; Okada et al., 1975; Stevens et al., 1975), and this type of infection may account for most asymptomatic HBsAg carriers found in adults (Sevens et al., 1975). In the few series of neonatal infection reported, considerable differences have been observed regard-ing the infants ' mothers, the clinical features of the infection, and the incidence of persistent infection in the children (Dupuy et al., 1975; Schweitzer, 1975; Stevens et al., 1975). In order to delineate the course of this infection in infants, a prospective study of all recognised cases of hepatitis B in children aged less than one year between 1970 and 1976 in the greater Copenhagen area (population 1.5 million) is presented. Materials and methods All obstetric and paediatric departments, and the department of infectious diseases, in the greater Copenhagen area reported any case in which infection with hepatitis B virus was suspected in a pregnant woman or in an infant. By surveying dis-charge summaries in 1976 we confirmed that no further cases had occurred. The diagnosis of hepatitis B infection was base