Distribution of HBV subgenotypes in Ribeirão Preto, Southeastern Brazil: a region with history of intense Italian immigration

Genetic diversity of hepatitis B virus quasispecies in different biological compartments reveals distinct genotypes

The selection pressure imposed by the host immune system impacts hepatitis B virus (HBV) quasispecies variability. This study evaluates HBV genetic diversity in different biological fluids. Twenty paired serum, oral fluid, and DBS samples from chronic HBV carriers were analyzed using both Sanger and next generation sequencing (NGS). The mean HBV viral load in serum was 5.19 ± 4.3 log IU/mL (median 5.29, IQR 3.01-7.93). Genotype distribution was: HBV/A1 55% (11/20), A2 15% (3/20), D3 10% (2/20), F2 15% (3/20), and F4 5% (1/20). Genotype agreement between serum and oral fluid was 100% (genetic distances 0.0-0.006), while that between serum and DBS was 80% (genetic distances 0.0-0.115). Two individuals presented discordant genotypes in serum and DBS. Minor population analysis revealed a mixed population. All samples displayed mutations in polymerase and/or surface genes. Major population analysis of the polymerase pointed to positions H122 and M129 as the most polymorphic (≥ 75% variability), followed by V163 (55%) and I253 (50%). Neither Sanger nor NGS detected any antiviral primary resistance mutations in the major populations. Minor population analysis, however, demonstrated the rtM204I resistance mutation in all individuals, ranging from 2.8 to 7.5% in serum, 2.5 to 6.3% in oral fluid, and 3.6 to 7.2% in DBS. This study demonstrated that different fluids can be used to assess HBV diversity, nonetheless, genotypic differences according to biological compartments can be observed.

Molecular Characterization of Hepatitis B Virus Infection in a Patient with Cutaneous Lupus Erythematosus

Hepatitis B virus (HBV) infection is a serious global health problem. Patients with autoimmune diseases, such as Lupus Erythematosus, are exposed to a higher risk of acquiring infections. In this study, a molecular characterization, genomic investigation of the Hepatitis B virus, polymerase (P) and surface (S) genes, from a patient affected by Cutaneous Lupus Erythematosus (CLE), was presented. Viral DNA was extracted from 200 μL of serum, and the HBV-DNA was amplified by real-time polymerase chain reaction (PCR) with the Platinum Taq DNA Polymerase. The PCR products were purified and sequencing reactions were performed. A phylogenetic analysis was performed through maximum likelihood and Bayesian approaches. The HBV CLE isolate was classified as sub-genotype D3 and related to other Italian HBV D3 genomes, and some from foreign countries. No drug resistant mutations were identified. One mutation (a.a. 168 M) was located in the last part of the major hydrophilic region (MHR) of the surface antigen (HBsAg). Moreover, three sites (351G, 526Y, 578C) in the polymerase were exclusively present in the CLE patient. The mutations identified exclusively in the HBsAg of our CLE patient may have been selected because of the Lupus autoantibodies, which are characteristic in the Lupus autoimmune disease, using a possible molecular mimicry mechanism.

Genetic Diversity and Possible Origins of the Hepatitis B Virus in Siberian Natives

A total of 381 hepatitis B virus (HBV) DNA sequences collected from nine groups of Siberian native populations were phylogenetically analyzed along with 179 HBV strains sampled in different urban populations of former western USSR republics and 50 strains from Central Asian republics and Mongolia. Different HBV subgenotypes predominated in various native Siberian populations. Subgenotype D1 was dominant in Altaian Kazakhs (100%), Tuvans (100%), and Teleuts (100%) of southern Siberia as well as in Dolgans and Nganasans (69%), who inhabit the polar Taimyr Peninsula. D2 was the most prevalent subgenotype in the combined group of Nenets, Komi, and Khants of the northern Yamalo-Nenets Autonomous Region (71%) and in Yakuts (36%) from northeastern Siberia. D3 was the main subgenotype in South Altaians (76%) and Buryats (40%) of southeastern Siberia, and in Chukchi (51%) of the Russian Far East. Subgenotype C2 was found in Taimyr (19%) and Chukchi (27%), while subgenotype A2 was common in Yakuts (33%). In contrast, D2 was dominant (56%) in urban populations of the former western USSR, and D1 (62%) in Central Asian republics and Mongolia. Statistical analysis demonstrated that the studied groups are epidemiologically isolated from each other and might have contracted HBV from different sources during the settlement of Siberia.

Hepatitis B virus genotypes and subgenotypes and the natural history and epidemiology of hepatitis B

INTRODUCTION AND OBJECTIVES

Espírito Santo state is considered a region with a higher frequency of hepatitis B virus infection. This study characterized demographic, epidemiological, laboratory, virological and clinical aspects of 587 chronic HBV carriers followed up at the University of Espírito Santo Hospital.

MATERIALS AND METHODS

Demographic, epidemiological, laboratory and clinical data were extracted from medical records during the entire follow-up period. Classification of the evolutionary phases of chronic hepatitis B was defined as immunotolerant; inactive carrier; chronic active hepatitis HBeAg (+)  and HBeAg (-). Characterization of HBV genotypes/subgenotypes was performed by sequencing of overlapping surface antigens and HBV DNA polymerase genes. Phylogenetic relationships were determined using BEAST 1.8.3 software.

RESULTS

and Conclusions: Genotypes found were A (132/65.3%) [A1 = 129 (63.9%) and A2 = 3 (1.5%)], D (66/32.7%) [D3 = 56 (27.7%), D4 = 8 (4.0%) and D2 = 2 (1.0%)] and F (4/2.0%) - all F2a. Subgenotypes A1 or D3 were not associated with age, sex, HIV/HCV co-infection, viral load, antiviral usage, HBeAg status or clinical stages of chronic hepatitis B. Mother -to-child-transmission (MTCT) was associated with the subgenotype A1 and intrafamilial transmission with subgenotype D3. Subgenotype A1 was more frequent than D3 among individuals born outside ES compared to those born in ES.

CONCLUSIONS

The most predominant clinical phases were HBeAg (-), inactive carrier and chronic active hepatitis HBeAg (-). Subgenotypes A1 and D3 were most frequent and were associated were MTCT and intrafamilial transmission of HBV, respectively.

Hepatitis B in the Northwestern region of Sao Paulo State: genotypes and resistance mutations

In Brazil, few studies on the molecular aspects of hepatitis B virus (HBV) infection have been conducted in the interior regions of Sao Paulo State. This study aimed to identify HBV genotypes and evaluate strains with resistance mutations for nucleoside analogues in the Administrative Region (AR) of the municipality of Sao Jose do Rio Preto. We performed nested PCRs of 127 samples from the Health Care Services of the AR to amplify, sequence and analyze fragments of the HBV DNA, in order to identify genotypes and resistance mutations. The HBV S/Pol regions of 126 samples were successfully amplified and sequenced. Five different genotypes were found, and the main ones were A, D and F; a greater number of samples contained the subgenotypes A1 (n = 51; 40.5%), D3 (n = 36; 28.6%), A2 (n = 14; 11.1%) and F2a (n = 9; 7.1%). Resistance mutations (rtM204V/I/S) associated or not with compensatory mutations (rtL180M, rtV173L) were identified in 13.9% (5/36) of patients undergoing viral treatment and 1.1% (1/90) of naïve patients. The diversity of genotypes/subgenotypes found is probably due to the intense migration occurring in the region. These data can complement epidemiological and clinical surveillance, and can be used for a more effective management of chronic HBV patients.

Temporal and geographic spreading of hepatitis B virus genotype A (HBV-A) in Brazil and the Americas

Hepatitis B virus genotype A (HBV-A) is disseminated in different countries around the world. It presents a high genetic diversity and is classified into seven subgenotypes (A1-A7). HBV-A1 and HBV-A2 are the most frequent and spread in almost all American countries. This study aimed to evaluate the molecular epidemiology of these two subgenotypes, with a special focus on the temporal and geographic spreading in the Americas and Brazil. Bayesian coalescent analyses with HBV-A1 and HBV-A2 whole-genome sequences were performed to study viral phylodynamic and phylogeography. HBV-A1 evolutionary history demonstrated that it was initially disseminated from Africa to other continents probably after the 1400s and mainly in the 17th-18th centuries. The whole viral population grew between the 1700s-1900s and then reached a stationary phase. In Brazil, HBV-A1 common ancestors dated back to the 1600s with successive introductions between the 17th-18th centuries. In contrast, HBV-A2 spread from Europe to other continents after the 1800s, with an increase in the viral population over decades. It was introduced in the 20th century in America and between the 1950s-1970s in Brazil, presenting a high increase in the viral population from the 1970s to the 1980s. The circulation continents for HBV-A1 are Africa and America, while for HBV-A2 are Europe and America. HBV-A is one of the predominant genotypes in America (including Brazil) because of the early introduction by human migration processes of the subgenotypes A1 and A2 between the 16th and 20th centuries and the continuous spreading inside the continent over time.

Hepatitis B virus genotypes in Brazil: Introduction and dissemination

Hepatitis B is a viral infectious disease highly spread worldwide with a long evolutionary history associated with human migrations through the continents and countries. Hepatitis B virus (HBV) was disseminated probably from Africa and diverged into ten genotypes (HBV-A to HBV-J) distributed around the world. In Brazil, almost all HBV genotypes were already reported, with a predominance of three ones: A (52.1%), D (36.8%), and F (7.7%). This review aimed to evaluate the introduction and dissemination of the main HBV genotypes and subgenotypes in Brazil over the last centuries to explain the current epidemic scenario. The highest frequency of HBV-A is a consequence of the introduction and spreading of HBV-A1 in the 16th to 19th centuries due to the African slave trade, but the more recent introduction of HBV-A2 from Europe also contributed to the current situation. HBV-D is the second most frequent genotype because it was consecutively introduced by migrations from Europe (mainly subgenotype D3, but also D2) and the Middle East (D1) in the 19th to 20th centuries. On contrary, HBV-F (F1a, F1b, F2a, F2b, F3, and F4) was disseminated by the Amerindians in all South American countries, including Brazil, by migrations inside the continent for more than three centuries ago. Other HBV genotypes are rare and eventually frequent in some human groups because of the dissemination by very specific epidemiological routes. In conclusion, the current scenario of the HBV epidemics is a consequence of the introduction and dissemination of some subgenotypes from the three main genotypes A, D, and F over the last five centuries.

Tracing back hepatitis B virus genotype D introduction and dissemination in South Brazil

Hepatitis B virus (HBV) infection is widespread and it is considered a major health problem in the world. HBV is classified into genotypes and subgenotypes. HBV genotype D (HBV-D) has been detected worldwide with high prevalence in some specific regions from Europe and South America. In Brazil, this genotype is very frequent in the South region and its introduction and dissemination have been associated with European immigration (mainly Italian). The present study aimed to trace back the introduction and dissemination of HBV-D in South Brazil. Fifty-two chronic hepatitis B patients from two cities with an early history of Italian immigration in South Brazil were selected for the present study. HBV-DNA was detected, quantified and a partial genomic region (S/P overlapped genes) was amplified by PCR and sequenced for the determination of HBV genotypes/subgenotypes. HBV complete genome sequences of some selected samples were further obtained. Bayesian coalescent analyses were performed to estimate the HBV-D evolutionary dynamics. Phylogenetic analysis demonstrated the occurrence of three genotypes according the tree topology: HBV-D (n = 49; 94.2%), HBV-A (n = 2; 3.9%) and HBV-G (n = 1; 1.9%). In addition, HBV-D presented three subgenotypes: HBV-D3 (n = 39; 79.6%), HBV-D2 (n = 8; 16.3%), and HBV-D1 (n = 2; 4.1%). The Bayesian coalescent analysis demonstrated that the HBV-D was introduced in the 20th century. HBV-D3 was the first to be introduced in South Brazil, probably between 1904 and 1942. HBV-D2 and HBV-D1 were introduced later; HBV-D2 between 1946 and 1953 and HBV-D1 between 1954 and 1969. HBV-D3 spread at a high rate from the 1920s to the 1980s, while HBV-D2 showed a slower growth from the 1960s to the 1990s and HBV-D1 infections demonstrated low and constant population size across time. After the 2000s, a stationary growth was detected for all these three-D subgenotypes. HBV-D showed a high prevalence in South Brazil and this is possibly associated with the first introduction and dissemination of HBV-D3 at the beginning of the 20th century.

Molecular Epidemiology of Hepatitis B Virus in Turkish Cypriot

There is an increased demand for molecular and epidemiological information regarding Hepatitis B Virus (HBV) infection as the disease severity depends on these specifications. We have aimed to analyze nucleos(t)ide analogues (NA) resistance and typical HBsAg escape mutations with the dispersion of HBV genotype/subgenotype/HBsAg serotypes on overlapping pol/S gene regions in the Turkish population. Samples were collected in Northern Cyprus. Reverse transcriptase (rt) region between 80–250 amino acids were amplified. Typical HBsAg escape mutations were determined as HBIg escape (6.48%), vaccine escape (8.34%), HBsAg misdiagnosis (9.25%), and immune escape mutations (8.34%). NAs resistances were determined as primary (2.78%), partial (2.78%), and compensatory mutations (26.85%) in overlapping pol/S gene region. The study patients were predominantly infected with HBV genotype D/D1 (98%). However, the predominant HBsAg serotype was ayw2 (99%). The most common NA resistance mutation was rtQ215H/P/S (16.67%), however, for S gene the misdiagnosis mutations were observed most frequently (9.25%). We can conclude that HBV D/D1 is the dominant strain and ayw2 is the dominant serotype in the Turkish Cypriot. Cyprus is an island located in the Eastern Mediterranean region, and it is, therefore, a key location for human trafficking and immigration; as a result of this reputation, it is necessary to analyze HBV phylogenetically for local dynamics, and our results indicate that treatment naïve population is prone to these pol/S gene mutations. However, if HBV strains were also analyzed among Greek Cypriots too, this would enable a complete island survey. With this work, we believe that we have enlightened this subject for further research.

Genetic Diversity of the Hepatitis B Virus Subgenotypes in Brazil

Hepatitis B virus (HBV) subgenotypes may be related to clinical outcomes and response to antiviral therapy. Most Brazilian studies on HBV subgenotypes are restricted to some regions and to specific population groups. Here, we provide an insight about genetic diversity of HBV subgenotypes in 321 serum samples from all five geographical regions, providing a representative overview of their circulation among chronic carriers. Overall, HBV/A1 was the most prevalent subgenotype, being found as the major one in all regions except in South Brazil. Among HBV/D samples, subgenotype D3 was the most prevalent, found in 51.5%, followed by D2 (27.3%) and D4 (21.2%). D2 and D3 were the most prevalent subgenotypes in South region, with high similarity with European strains. D4 was found in North and Northeast region and clustered with strains from Cape Verde and India. For HBV/F, the most frequent subgenotype was F2 (84.1%), followed by F4 (10.1%) and F1 (5.8%), closely related with strains from Venezuela, Argentina and Chile, respectively. Phylogeographic analyses were performed using an HBV full-length genome obtained from samples infected with genotypes rarely found in Brazil (B, C, and E). According to Bayesian inference, HBV/B2 and HBV/C2 were probably introduced in Brazil through China, and HBV/E from Guinea, all of them mostly linked to recent events of human migration. In conclusion, this study provided a comprehensive overview of the current circulation of HBV subgenotypes in Brazil. Our findings might contribute to a better understand of the dynamics of viral variants, to establish a permanent molecular surveillance on the introduction and dispersion patterns of new strains and, thus, to support public policies to control HBV dissemination in Brazil.

HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil

Background

Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil.

Objective

To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence.

Methods

A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients.

Results

The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each.

Conclusions

These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

Evidências científicas sobre a hepatite Delta no Brasil: revisão integrativa da literatura

Resumo Objetivo: Descrever o nível de evidência científica sobre a infecção por vírus da hepatite Delta (VHD) no Brasil. Métodos: Revisão integrativa da literatura, com buscas realizadas nas bases de dados do Medical Literature Analysis and Retrieval System Online, Literatura Latino-americana e do Caribe em Ciências da Saúde, Scientific Eletronic Library Online e Scopus, com análise centrada no nivelamento do rigor metodológico de acordo com o modelo de Melnyk e Fineout-Overholt. Resultados: A busca revelou uma média de duas publicações por ano no intervalo entre 1987 e 2017. Foram selecionados 33 artigos, tendo a maioria (91%) apresentado nível de evidência VI. As publicações ficaram concentradas em periódicos da área de medicina tropical (46%) e virologia (15%). Dos trabalhos, 85% tinha profissional médico com autor e o delineamento mais encontrado foi o descritivo/transversal (69,6%). Conclusão: A produção científica sobre a infecção por VHD no Brasil está centrada em estudos de prevalência, mostrando-se incipiente quanto à produção de estudos com delineamentos mais rígidos como ensaios clínicos.

Basal core promoter and precore mutations among hepatitis B virus circulating in Brazil and its association with severe forms of hepatic diseases

BACKGROUND

In Brazil, few studies have investigated the prevalence of infection with the precore (PC) and basal core promoter (BCP) mutants of the hepatitis B virus (HBV).

OBJECTIVES

This study aimed to analyse the frequency of PC and BCP mutations among patients infected with HBV and to evaluate the association between the variants and advanced hepatic disease.

METHODS

A total of 161 patients infected with HBV were studied. To identify PC and BCP mutations, a 501-bp fragment of HBV DNA was amplified and sequenced.

FINDINGS

PC and BCP regions from HBV strains were successfully amplified and sequenced in 129 and 118 cases, respectively. PC and BCP mutations were detected in 61.0% and 80.6% of the cases, respectively. The A1762T/G1764A variant was identified in 36.7% of the patients with grade 1 and 2 liver fibrosis (29/79) and in 81.8% of the patients with grade 3 and 4 liver fibrosis (9/11) (p < 0.01); in 76.9% of the patients with cirrhosis (10/13) and in 38.1% of the patients without cirrhosis (40/105) (p = 0.01); and in 77.8% of the patients with hepatocellular carcinoma (HCC) (7/9) and in 39.4% of the patients without HCC (43/109) (p = 0.03).

MAIN CONCLUSIONS

A high prevalence of HBV PC and BCP mutants was found. The A1762T/G1764A variant was independently associated with advanced forms of liver fibrosis, hepatic cirrhosis, and HCC.