Hepatitis B virus genotype G epidemiology and co-infection with genotype A in Canada

1 Bloodborne Pathogens and Hepatitis, National Microbiology Laboratory, Winnipeg, MB, Canada 2 Section of Hepatology, Department of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada 3 Hôpital Saint Luc du Centre Hospitalier, Universitaire de Montréal, Montréal, QC, Canada Correspondence Carla Osiowy carla_osiowy{at}phac-aspc.gc.ca Hepatitis B virus (HBV) genotype G (HBV/G) is an unusual variant, and little is known about its epidemiology and natural history, particularly the requirement for a co-infecting HBV genotype and their relationship during infection. This study investigated the quasispecies nature of co-infecting genotypes in 39 samples collected over a 6 year period from 13 HBV/G-infected patients. HBV/G infections were found to occur predominantly in males (92 %) and were primarily associated with male homosexual sex (67 %). All patients were infected with HBV/G and HBV/A, or a recombinant HBV/A/G strain. Co-infecting genotypic prevalence was often observed to fluctuate over time, with periods of HBV/G monoinfection in some patients. The average sequence divergence among Canadian HBV/G strains was 1.57±0.62 %. Thus, all HBV/G infections in Canada occur in the context of co-infection or recombination with HBV/A, and strains display increased sequence divergence compared with all known HBV/G sequences described to date. Present address: Applied Biosafety Research Program, National Microbiology Laboratory, Winnipeg, MB, Canada. The GenBank/EMBL/DDBJ accession numbers for the sequences reported in this paper are EU833889, EU833890 and EU833892–EU833930. A supplementary figure is available with the online version of this paper.