High prevalence of hepatitis B virus dual infection with genotypes A and G in HIV-1 infected men in Amsterdam, the Netherlands, during 2000-2011

Abstract

Background: Hepatitis B virus (HBV) is divided into 8 definite (A-H) and 2 putative (I, J) genotypes that show a geographical distribution. HBV genotype G, however, is an aberrant genotype of unknown origin that demonstrates severe replication deficiencies and very little genetic variation. It is often found in co-infections with another HBV genotype and infection has been associated with certain risk groups such as intravenous drug users and men having sex with men (MSM). We aimed to estimate the prevalence of HBV-G in the Netherlands by analysing samples from HBV-positive patients visiting the Academic Medical Center in Amsterdam.

Methods: Ninety-six HBV-infected patients, genotyped as HBV-A or HBV-G infected, were retrieved from the clinical database. Blood plasma samples were analysed with a newly-developed real-time PCR assay that detects HBV-A and HBV-G. For three patients, the HBV plasma viral load (pVL) of both genotypes was followed longitudinally. In addition, three complete genomes of HBV-G were sequenced to determine their relationship to global HBV-G strains.

Results: Ten HBV-G infections were found in the selected Dutch patients. All concerned HIV-1 infected males with HBV-A co-infection. Dutch HBV-G strains were phylogenetically closely related to reference HBV-G strains.

Conclusions: In this study, HBV-G infection in the Netherlands is found exclusively in HIV-1 infected men as co-infection with HBV-A. A considerable percentage (37%) of men infected with HBV and HIV-1 are actually co- infected with two HBV genotypes.

Figure 1

Percentages of HBV genotypes A-G in HBV-infected patients from Amsterdam. HBV genotypes were determined by the Laboratory of Clinical Virology of the AMC (Amsterdam, the Netherlands) during 2000-2011.

Figure 2

Phylogenetic analysis of full-length HBV sequences. The neighbour-joining tree was generated with the MEGA5 software package [38] and shows the relationship between three novel, full-length HBV-G strains from the Netherlands (indicated by red circles) and reference sequences of HBV genotypes A1, A2, C, D1, D2 and G obtained from the NCBI nucleotide database [35]. Distances were estimated with the Kimura 2-parameter method, and bootstrap resampling was done with 1000 replicates. The accession number of the reference sequences is indicated together with the HBV genotype.

Figure 3

Longitudinal analysis of the HBV-A and -G pVL in three male HIV-1 infected patients. Panel A = patient 7; panel B = patient 12; panel C = patient 23. The HIV-1 pVL is indicated with red bars; numbers in red are HIV-1 copies/ml. ART regimens are shown below the graphs. Abbreviations: 3TC = lamivudine; ABC = abacavir; ATV = atazanavir; d4T = stavidine; DRV = darunavir (boosted with RTV); EFV = efavirenz; FTC = emtricitabine; IDV = indiniavir; NVP = nevirapine; RTV = ritonavir; TDF = tenofovir. 3TC and TDF are also effective against HBV.