Molecular evolutionary analysis of the complete nucleotide sequence of hepatitis B virus (HBV) in a case of HBV infection acquired through a needlestick accident

To elucidate needlestick transmission of hepatitis B virus (HBV), strains i solated from 1 physician who acquired HBV infection through a needlestick a ccident and 3 patients with chronic hepatitis B (donor patients A, B, and C ) were tested using molecular evolutionary analysis based on full-length HB V genomic sequences. Nucleotide sequences of these isolates were aligned wi th 55 previously reported full-length genomic sequences. Genetic distances were estimated using the 6-parameter method, and phylogenetic trees were co nstructed using the neighbor-joining method. Strains isolated from patient A and the recipient pair were clustered within a closer range of evolutiona ry distances than were strains recovered from the recipient pair and patien ts B and C, Furthermore, strains from patient A and the recipient were also clustered on the S gene sequences of HBV, These results demonstrated that patient A alone was the source of direct transmission to the recipient. Thi s approach can be used to investigate the transmission route of HBV.