The release of B19 DNA-positive blood products with a concentration of less than 105 IU per mL is thought to be safe due to the high level of neutralizing VP2 antibodies and is currently examined in a donor recipient infectivity study. In contrast, blood products with a high B19 DNA concentration (> or =10(5) IU/mL), some of which did not contain neutralizing antibodies, were discarded to protect at risk individuals.

B19 transmission by cellular blood products correlates with the virus concentration and the concentration of neutralizing antibodies. Thus, blood donor screening for B19 by minipool NAT should be done to supply at-risk patients (e.g., immunosuppressed patients) with B19-negative blood components.