Characterization of Hepatitis B virus based complete genome analysis improves molecular surveillance and enables identification of a recombinant C/D strain in the Netherlands

Hepatitis B Virus (HBV) is classified into 10 HBV genotypes (A-J) based a >7.5 % divergence within the complete genome or a >4 % divergence in the S-gene. In addition, recombinant strains with common breakpoints at the gene boundaries of the preS1/preS2/S- and preC/C-gene are often identified. Analysis of HBV based on the complete genome is essential for public health surveillance as it provides higher genetic resolution to conduct accurate characterization and phylogenetic analysis of circulating strains and identify possible recombinants. Currently two separate assays are used for HBV-surveillance; the S-gene for typing, and due to the higher genetic variation, the C-gene to gain insight in transmission patterns.The aim of the study was to develop a complete genome PCR-assay and evaluate the characterization and circulation of HBV strains through the use of the S-gene, C-gene and complete genome. For this HBV positive samples collected in the period 2017 through 2019 were selected.Analysis of the complete genome showed that complete genome analysis portrays a high genetic resolution that provided accurate characterization and analysis of the different circulating types in the Netherlands and enabled identification and characterization of a recombinant CD strain.