Département des agents transmissibles par le sang, Institut national de la transfusion sanguine, 6, rue Alexandre-Cabanel, 75015 Paris
Sequence analysis of human erythroviruses shows an organization into three genotypes; genotype 1 with B19 Parvovirus (B19V) and 2 new genotypes with a genetic diversity markedly distinct from that of B19V. The frequency of each genotype depends on geographic origin and population. Human erythroviruses infection can be transmitted by transfusion. In immunocompetent recipients, B19V exposure is generally inconsequential, since a large proportion is immunized. However, such a contamination may have severe clinical outcome in not immunized patients with shortened red cell survival, in seronegative pregnant women and in immunocompromised patients. No prevention of blood transmission is currently performed, but a preventive strategy could be discussed for at-risk recipients. In plasma derivatives, B19V-DNA screening is done with a threshold of 10
4 IU/mL. With recent data of a new classification on the human erythroviruses genotypes, DNA testing assays would be validated in accordance with genetic variability, in order to guarantee optimal safety.