Transfusion-transmitted human parvovirus B19 infections during a “fifth disease” epidemic: 1-year follow-up of adults with malignant haematological diseases

Background We characterized transfusion-associated human parvovirus B19 (PVB19) infections among adults with malignant haematological diseases during a fifth-disease epidemic. Methods We conducted a prospective observational cohort study at a tertiary centre in Budapest, Hungary. Consecutive adults with malignant haematological disease or HSCT, and transfusion-associated infection were included, confirmed by two peripheral blood qPCR tests within 7 days. Patients underwent weekly qPCR monitoring, and received IVIG, with cidofovir in selected cases. Follow-up continued until 1-year, last visit or death. Outcomes were overall survival and PVB19-associated complications. Results Forty transfused blood products were PVB19-contaminated (0.91%), and 15/40 exposed recipients developed infection (37.5%; median age 58 years; 46.7% male). Seven developed complications (46.7%), including haemophagocytic lymphohistiocytosis (n=3), ongoing aplasia (n=4), acute liver failure, pneumonitis and pure red cell aplasia (n=1 each). All patients received IVIG, three received cidofovir. Baseline PVB19 DNA was ≥10⁴ copies/mL in seven patients (46.7%), and within 60 days, 40.0% achieved ≥1-log₁₀ PVB19 DNA reduction. Nine (60.0%) patients showed a day-3 reticulocyte decline, followed by recovery. Overall survival was 73.3% at 60 days, and 53.3% at 1-year. Conclusions Transfusion-associated PVB19 infection affected over one-third of exposed recipients and was associated with a clinically relevant morbidity burden.