Clinical course and duration of viremia in vertically transmitted hepatitis E virus (HEV) infection in babies born to HEV-infected mothers

Summary.  Infection with the hepatitis E virus (HEV) causes a self-limiting acute hepatitis. However, prolonged viremia and chronic hepatitis has been reported in organ transplant recipients. Vertically transmitted HEV infection is known to cause acute hepatitis in newborn babies. The clinical course and duration of viremia in vertically transmitted HEV infection in neonates in not known. We studied 19 babies born to HEV infected mothers. Babies were studied at birth and on a monthly basis to evaluate clinical profile, pattern of antibody response and duration of viremia in those infected with HEV. Fifteen (78.9%) babies had evidence of vertically transmitted HEV infection at birth (IgM anti-HEV positive in 12 and HEV RNA reactive in 10) and three had short-lasting IgG anti-HEV positivity because of trans-placental antibody transmission. Seven HEV-infected babies had icteric hepatitis, five had anicteric hepatitis and three had high serum bilirubin with normal liver enzymes. Seven babies died in first week of birth (prematurity 1, icteric HEV 3, anicteric HEV 2 and hyperbilirubinemia 1). Nine babies survived and were followed up for clinical, biochemical, serological course and duration of viremia. Five of 9 babies who survived were HEV RNA positive. HEV RNA was not detectable by 4 weeks of birth in three babies, by 8 weeks in one and by 32 weeks in one. All surviving babies had self-limiting disease and none had prolonged viremia. Thus HEV infection is commonly transmitted from mother-to-foetus and causes high neonatal mortality. HEV infection in survivors is self-limiting with short lasting viremia.