Identification of Novel Recombinant Forms of Hepatitis B Virus Generated from Genotypes Ae and G in HIV-1-Positive Japanese Men Who Have Sex with Men

High Frequency of Antiviral Resistance Mutations in HBV Genotypes A2 and H: Multidrug Resistance Strains in Mexico

Background and Aims

Lamivudine (3TC), telbivudine (LdT), entecavir (ETV), adefovir (ADF), and tenofovir (TFV) are drugs used to treat hepatitis B virus (HBV) infection, but specific mutations allow some viruses to become resistant to antiviral drugs or to acquire immune escape capacities. These mutations have not been thoroughly investigated in Mexico. This study aimed to estimate the prevalence of HBV antiviral resistance and escape mutations.

Methods

This cross-sectional study analyzed 158 samples. HBV DNA was extracted, amplified, and sequenced in serum samples using the spin column method, PCR assay, and Sanger's sequencing, respectively. HBV genotypes were determined, and HBV mutations were tested using the Geno2pheno tool.

Results

Overall, 68.4% (108/158) of HBV patients were infected with genotype H, followed by G (11.4%, 18/158), A2 (10.8%, 17/158), F1b (6.9.0%, 11/158), D (1.9%, 3/158), and E (0.6%, 1/158), and 5.1% (8/158) had evidence of recombination. The prevalence of resistance mutations was 8.2% (13/158) and the most common combined mutation was rt180M+rt204V. Notably, we found the combinations rt180M+rt204V+rt173L (n=2) and rt180M+rt204V+rt202G (n=1) that confer multidrug resistance to 3TC, LdT, and ETV. Resistance mutations were found in genotypes A2 (11.8%, 2/17), and H (10.2%, 11/108), and escape mutations were detected in HBV genotypes A2 (11.8%, 2/17), H (10.2%, 11/108), F1b (9.1%, 1/11) and G (5.6%, 1/18).

Conclusions

The highest prevalence of antiviral resistance mutations or escape mutations was detected in HBV genotypes A2 and H. The earliest cases of HBV multidrug resistance were detected in Mexico.

Hepatitis B Virus (HBV) Genotype Mixtures, Viral Load, and Liver Damage in HBV Patients Co-infected With Human Immunodeficiency Virus

Hepatitis B virus (HBV) co-infection is possible in patients who are positive for human immunodeficiency virus (HIV) since both share similar transmission routes. Furthermore, through the continuous risk of exposure, they potentially can be infected by mixtures of distinct HBV genotypes which can result in the presence of two or more genotypes in a single patient. This study aimed to specify the frequency of mixtures of HBV genotypes and their potential clinic importance in HIV-infected Mexican patients. HBV infection was assessed by serological testing and molecular diagnostics. HBV mixtures were detected by multiplex PCR and DNA sequencing. Liver fibrosis was evaluated using transitional elastography, the Aspartate aminotransferase to Platelets Ratio Index score, and Fibrosis-4 score. Among 228 HIV-infected patients, 67 were positive for HBsAg. In 25 HBV/HIV co-infected patients, 44 HBV genotypes were found: H (50.0%, 22/44), G (22.7%, 10/44), D (15.9%, 6/44), A (9.1%, 4/44), and F (2.3%, 1/44). Among these, 44.0% (11/25) were single genotype, 36.0% (9/25) were dual and 20.0% (5/25) were triple genotype. The most frequent dual combination was G/H (44.4%, 4/9), while triple-mixtures were H/G/D (60.0%, 3/5). The increase in the number of genotypes correlated positively with age (Spearman’s Rho = 0.53, p = 0.0069) and negatively with platelet levels (Spearman’s Rho = − 0.416, p = 0.039). HBV viral load was higher in triply-infected than dually infected (31623.0 IU/mL vs. 1479.0 IU/mL, p = 0.029) patients. Triple-mixed infection was associated with significant liver fibrosis (OR = 15.0 95%CI = 1.29 – 174.38, p = 0.027). In conclusion, infection with mixtures of HBV genotypes is frequent in HIV patients causing significant hepatic fibrosis related to high viral load, especially in triple genotype mixtures.

Prevalence and burden of HBV co-infection among people living with HIV: A global systematic review and meta-analysis

Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV.

Circulation of Distinct Treponema pallidum Strains in Individuals with Heterosexual Orientation and Men Who Have Sex with Men

Human treponematosis is caused by various pathogenic Treponema pallidum subspecies, including T. pallidum subsp. pallidum, T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and Treponema carateum The global prevalence of syphilis has been increasing since the 2000s. Men account for more than 90% of the cases, with the majority being men who have sex with men (MSM). In Japan, the increase in the number of syphilis patients began in 2011, a 10-year delay from the global trend. In 2017, a total of 5,829 syphilis cases (3,934 men and 1,895 women) were reported, with an outstanding increase in cases among young adult women; the number reported for women age 15 to 20 years was 1,100. Hence, a molecular epidemiological study was conducted on circulating T. pallidum strains using two strain typing methods, the enhanced CDC method and sequencing-based molecular typing. Clinical specimens from 95 adults suspected of syphilis were collected from September 2013 to August 2017 in Osaka, Japan. T. pallidum DNA was detected in specimens from 25 males and 11 females, including seven MSM. The majority of the heterosexual patients (66.7% and 90.9% of males and females, respectively) were positive for 14d/f-SSR8. In contrast, the genotypes identified in the MSM group were significantly divergent. T. pallidum subsp. endemicum was notably identified in two MSM patients. Macrolide-sensitive or Nichols-like strains were significantly associated with the MSM group. These data suggest that distinct T. pallidum strains were circulating in the heterosexual and MSM groups. Our findings imply that independent factors may contribute to the increased syphilis prevalence in heterosexual and MSM populations.

Human immunodeficiency virus and hepatitis B genotype G/A2 recombinant co-infection: a case study

Background

Hepatitis B virus (HBV) genotypes have distinct geographical distributions and are associated with different clinical courses. HBV genotype G (HBV/G) is extremely rare among Human immunodeficiency virus (HIV) infected populations in Japan. Genetic analysis and clinical course of recombinant forms with HBV/G infection are seldom reported in the literature.

Case presentation

A 36-year old homosexual man with HIV infection was referred to a general hospital for assessment of chronic HBV infection. We cloned full-length HBV isolates and determined the complete genome sequences of 2 obtained clones, although mixture of multiple variant with different length is detected by HBV-DNA genotyping. The Bootscaning analysis using a full-length HBV genome revealed the clones represented as the HBV/A2 and the HBV/G/A2 recombinant strain. The HBV-DNA decreased from >9.1 to 2.5 log copies/mL after 24 months of antiretroviral therapy.

Conclusions

This patient was co-infected with HBV/A2 and HBV/G/A2 recombinant strain. This recombinant strain was not identical to HBV/G/A2 strains previously reported from Japan. Recombination with other genotypes could alter the clinical manifestations of chronic hepatitis B in people living with HIV.

Virological characteristics of hepatitis B genotype G/A2 recombination virus in Japan

AIM

We identified four cases of infection with hepatitis B virus genotype G and A2 recombinant (HBV/G/A2) strains, which were initially overlooked by enzyme immunoassay-based genotyping. The patients were all men who have sex with men (MSM) and inhabited several metropolitan areas of Japan, suggesting that the recombinant strains may be circulating among high-risk groups such as MSM. Here, we investigated the genomic structure and virological properties of the HBV/G/A2 strains.

METHODS

Complete genome sequences of the isolates were determined and phylogenetically analyzed. Replication efficiency of HBV/G/A2 was investigated by transfecting plasmids containing 1.24-fold viral genome. The in vivo viral kinetics of HBV/G/A2 were investigated using chimeric mice with humanized livers.

RESULTS

Phylogenetic analysis revealed that the four strains were almost identical (>99.7% homologous). The preS2/S region of these strains was highly homologous to that of genotype A2 and the remaining region was almost identical to that of genotype G, reflecting inter-genotypic recombination. Interestingly, in all four cases, genotype A was co-infected as a minor population. In vitro analysis revealed that HBV/G/A2 had a low replication rate. Although detectable viremia was not measurable following the inoculation of HBV/G/A2 into chimeric mice, subsequent superinfection of HBV genotype A greatly enhanced HBV/G/A2 replication and viral spread.

CONCLUSION

We found that four cases of HBV/G/A2 recombinant among MSM patients in the metropolitan areas of Japan, and HBV/A co-infections are required for its efficient replication. High-risk groups such as MSM should be carefully tested for infection of genotype G-derived variants.