Figure 3: Phylogenetic trees based on the surface gene in hepatitis B virus (HBV) strains isolated from 3 children in this study, and 45 reference strains. Numbers in the tree indicate bootstrap reliability. The lengths of horizontal bars indicate the number of nucleotide substitutions per site. Isolates from the database are indicated by their accession number, and relevant country names have been added to each HBV/B, HBV/C, and HBV/D strain.