Human Parvovirus 4 in Kidney Transplant Patients, France

To the Editor: Human parvovirus 4 (PARV4) is a recently identified virus, distantly related to already known members of the family Parvoviridae that affect humans and animals. Initially, PARV4 was characterized in the blood of a North American patient who had acute viral syndrome; a sequence-independent amplification approach was used (1). Molecular analysis of the viral prototype genome (5,268 nt) identified 2 large, nonoverlapping open reading frames (ORFs) and showed limited homology with human parvovirus B19 (<30% aa similarity). Subsequent phylogenetic analyses have shown that at least 2 genotypes are identifiable, differing by ≈8% at the nucleotide level (2).