Paired chimpanzee hepatitis B virus (ChHBV) and mtDNA sequences suggest different ChHBV genetic variants are found in geographically distinct chimpanzee subspecies.

The surface antigen gene region from five chronic hepatitis B virus (HBV) infected chimpanzees was amplified by PCR and the sequence determined. Sequence comparison confirmed that all of the sequences were chimpanzee hepatitis B virus (chHBV) and they appeared to represent three distinct clusters or branches. To address the question of whether the three branches represented recently identified subspecies of chimpanzees, we determined the sequence of the mitochondrial DNA hypervariable D loop from hair samples obtained from these five chimpanzees. The results indicated that the three chHBV branches reflected three distinct subspecies of chimpanzees that are from different geographic regions in West Africa. The complete HBV sequence from members of the Pan troglodytes troglodytes cluster and the Pan troglodytes verus cluster are in the published literature; we determined the complete genome sequence for the third branch of HBV present in Pan troglodytes vellerosus.