Case ReportReverse vertical transmission of hepatitis B virus (HBV) infection from a transfusion-infected newborn to her mother

Background & AimsClinical cases of viral infections possibly involving the transfusion of blood components are systematically investigated.MethodsSerological and molecular markers of hepatitis B virus were used including HBsAg, anti-HBc, anti-HBs, HBV DNA, and viral load. Full genome sequencing and phylogenetic analyses were performed.ResultsAn acute HBV infection was diagnosed in the mother of a 16-month-old daughter who had been transfused at age three weeks with one quarter of a regular red cell concentrate (RCC). The repeat donor of the index donation was free of HBV markers in two previous donations but seroconverted to anti-HBc and anti-HBs 3 months post-donation of a unit containing only low level of HBV DNA. One other newborn recipient of the same RCC was asymptomatically HBV infected. A third newborn recipient whose mother had been HBV vaccinated and carried moderate level of anti-HBs was not infected. Full length nucleotide sequence identity between HBV strains from the mother and the two infected transfusion recipients provided evidence of the transfusion origin of all three infections in the absence of donor sequence.ConclusionsReverse vertical HBV transmission was likely the result of casual mother contact with a baby carrying extremely high viral load. The blood products intended to immunodeficient newborn should be submitted to more thorough viral testing considering their increased susceptibility to infections.