Phylogenetic analysis of the B19V-NS1/VP1u region. (A) The phylogenetic tree has been inferred from the B19V-NS1/VP1u region (nt 2355 to nt 2690) of 39 B19V-samples. Topology was constructed by MEGA 5.0 software using the Neighbor-joining method with bootstrap values (in percent) indicating numbers from 1,000 replicates tested (values <40 were not shown). Major lineages of B19V are shown as branches. The two major B19V-subtypes 1A and 1B are shown . Scale bar at bottom indicates the number of nucleotide substitutions per site. Patient codes and the corresponding GenBank accession number are denoted (e.g., Af31m(KF309528)). Reference B19V-sequences were GenBank accession No. AB030694, AF113323, M13178 and AF162273 for B19V-genotype 1A, DQ357064, DQ357065, and KF417555 for B19V-genotype 1B, AY064476 and AY044266 for B19V-genotype 2, and AX003421 and AY083234 for B19V-genotype 3. (B) Genetic distance calculation (Kimura two-parameter model) of B19V-strains. Numbers at the left denote patient-specific B19V-strains and B19V-reference strains [Genbank numbers are denoted]:  M131178;  AB030694;  Af21s (KF309511);  Af13s (KF309513);  Af33s (KF309514);  Af34m;  Af41s (KF309516);  Af22m (KF309508);  DQ357064;  DQ357065;  AY064476;  AY044266;  Af2m (KF309519);  Af37s (KF3095021);  Af38s (KF3095020);  Af35s (KF3095027);  Af39s (KF3095022);  Af40s (KF3095026);  AY083234;  AX003421. B19V-reference strains are genotype 1: , , genotype 2: , , and genotype 3: , . Boxes represent data of the genetic distance calculation of the same genotype and sub-genotype.