Characteristics and outcome of acute infection with hepatitis B virus in children with cancer.

After an outbreak of hepatitis B virus (HBV) infection in a unit of pediatric oncology, the clinical outcome and HBV markers were followed in 1 child with chronic and 10 children with acute HBV infection for 12 months. Four children had acute hepatitis with jaundice whereas 7 of the infections were subclinical. Ten children had antecedent malignancies and 1 had aplastic anemia. Four patients died of causes unrelated to the hepatitis after periods of 2, 4, 8 and 10 months. All 3 children who were not immunosuppressed at the time of contracting the HBV infection quickly turned negative for hepatitis B surface antigen (HBsAg), whereas only 2 of 8 patients who were immunosuppressed by chemotherapy eventually became HBsAg-negative. The latter 8 patients were also hepatitis B e antigen (HBeAg)-positive. Two of them quickly cleared HBeAg, but 6 remained HBeAg-positive throughout the follow-up. In 6 of 9 patients HBsAg was also detected in saliva. These results suggest that children who are receiving anticancer chemotherapy have an increased risk of remaining HBeAg-positive and secreting HBsAg and possibly HBV in their saliva, which makes them particularly infective.