Introduction Parvovirus B19 (B19V) has been found in asymptomatic blood donors. This prospective study tested linked blood donor–recipient samples from patients transfused at the National Institutes of Health (NIH) and affiliated hospitals for the presence of B19V DNA and anti-B19 immunoglobulin G (IgG) antibodies to assess the risk of B19V transmission by transfusion. Materials and methods Post-transfusion recipient plasma samples collected during 2002–2020 were tested for B19V DNA at 1, 2, 4, and/or 8 weeks by nested polymerase chain reaction (PCR), and for anti-B19 IgG at 12 and ≥24 weeks by enzyme immunoassay (EIA). To confirm B19V DNA-positive recipients, pre-transfusion and linked donation samples were tested for B19V DNA, anti-B19 IgG, and/or IgM. Tested samples included 1,352 subjects tested for DNA and anti-B19V IgG, or both. Results No new transfusion-transmitted B19V infections were identified. Only one confirmed transfusion-transmitted infection (TTI) was identified overall. A total of 19 of 1,314 subjects tested for B19V DNA (1.4%, 95% confidence interval CI: 0.014 0.009, 0.021) had a positive result in their post-transfusion sample. A total of 876 of 1,290 tested subjects were positive for anti-B19V IgG antibody (68%, 95% CI: 0.679 0.65, 0.70). Antibody detection fluctuated among some recipients from 12 to 24 weeks. Discussion The B19V DNA-positive rate in recipients was very low. All B19V DNA-positive recipients had pre-existing antibodies, indicating prior exposure. Although these data may not provide enough evidence to consider revising current B19V testing strategies, other pooled plasma testing data from around the world suggest that more widespread B19V monitoring of blood products could be indicated to prevent B19V infection in immunosuppressed or otherwise susceptible recipients (e.g., individuals with chronic hematological diseases, pregnant women less than 20 weeks gestation).
Miller et al. (2026) studied this question.