Exposure of hematologic patients to parvovirus B19 as a contaminant of blood cell preparations and blood products.

BACKGROUND: Patients with hematologic malignancies often require blood products, and parvovirus B19 is known to be transmitted by this route. Primary infection with parvovirus B19 shows a wide variety of disease manifestation. In immunocompromised patients, symptoms are severe and viral clearance is delayed or missing.

STUDY DESIGN AND METHODS: A total of 2123 blood products given to all patients of a hematologic ward over a period of 6 months were retrospectively examined for the presence of parvovirus B19 DNA by an in-house real-time polymerase chain reaction (PCR; TaqMan). Patients who had received B19 DNA-positive blood products were further investigated serologically and by PCR for the presence of parvovirus B19 antibodies and DNA.

RESULTS: Twenty-one (1%) of 2123 blood products tested positive for the presence of B19 DNA (2% of pooled products, 0.7% of single-donor products, and 17.6% of allogeneic peripheral blood progenitor cells), the median viral load was 700 genome equivalents per mL. During the study period, 114 patients were treated on the ward, and 14 (12%) of them received B19 DNA-positive blood components. None of them developed symptoms of an acute B19 infection, although one had a short low-level viremia.

CONCLUSIONS: Although B19 DNA was detected in 1 percent of blood products given to hematologic patients, the exposure of 12 percent of patients did not result in symptomatic infections.