Human parvovirus infection in haemophiliacs first infused with treated clotting factor concentrates

A group of 27 first infused haemophiliacs was studied for association between heat-treated clotting factor concentrates and transmission of human parvovirus B19. The prevalence rate of B19 antibody, detected by the Immunoelectroosmophoresis (IEOP) reaction, was 55.5% in this group of first infused subjects, significantly higher than the 29.3% of the control group of 58 healthy blood donors but lower than the 93.3% of antibody positive subjects in a group of 30 haemophiliacs multitreated with unheated products. Five of 17 B19 antibody negative patients produced human parvovirus IgM, detectable by radioimmunoassay, after the first treatment with heated concentrates; two of them developed viraemia 6 and 10 days, respectively, after the first infusion dose. These results lead to the conclusion that human parvovirus is transmissible by blood derivatives even when they have been exposed to steam- or dry-heat treatment.