Hepatitis B Virus in Gabonese Non-Human Primate: Potential Zoonotic Circulation and Long-Term Strain Persistence

Orthohepanaviruses are viruses that infect a number of mammals, including humans and non-human primates. However, previous studies in great apes in Gabon in 2001 found one strain of hepadnavirus (HBV ChBassi strain) displaying genetic recombination between human, gorilla and chimpanzee strains, suggesting cross-species transmissions among primates. The aim of this study was to evaluate the presence of HBV DNA in non-human primates (NHPs) and to compare it with human HBV strains in order to assess the zoonotic potential. We analyzed feces from 1891 NHPs, collected in forests in Gabon, to find human HBV-related hepadnaviruses by amplifying a portion of the S gene using hemi-nested techniques, followed by sequencing. A total of 51 samples were PCR-positive. Thirteen of the fourteen sequences obtained after sequencing were phylogenetically more closely related to chimpanzee HBV strains, while the fourteenth sequence was associated with the ChBassi HBV strain. This study shows that HBV infection is endemic in wild-born great apes in Gabon. The detection of a strain genetically close to the Bassi strain (a potential zoonotic strain) highlights the need for more in-depth studies to provide an effective response as part of the 'One Health' initiative.