Hepatitis B virus genotypes from European origin explains the high endemicity found in some areas from southern Brazil

Core Promoter and Pre-Core Variants of the Hepatitis B Virus (HBV) Are Frequent in Chronic Hepatitis B HBeAg-Negative Patients Infected by Genotypes A and D

In Brazil, hepatitis B virus endemicity is low, moderate, or high in some areas, such as Espírito Santo State in the southeast region. In this study, we intend to characterize the basal core promoter (BCP) and pre-core region (PC) variants and their association with clinical/epidemiological disease patterns in patients infected with genotypes A and D. The study included 116 chronic hepatitis B patients from Espírito Santo State, Southeast Brazil, infected with genotypes A and D. Basal core promoter (BCP) and pre-core mutations were analyzed in these patients. The frequency of BCP and PC mutations was compared with age, HBeAg status, HBV genotype and subgenotype, HBV-DNA level, clinical classification, and transmission route. HBeAg-negative status was found in 101 (87.1%) patients: 87 (75.0%) were infected with genotype A (A1 = 85; A2 = 2) and 29 (25.0%) were infected with genotype D (D3 = 24; D4 = 3; D2 = 2). BCP + PC variants altogether were more frequent (48.1%) in genotype D than in genotype A strains (6.0%) (p < 0.001). When this evaluation was performed considering the cases that presented only the A1762T and/or G1764A (BCP) mutations, it was observed that the frequency was higher in genotype A (67.5%) compared to genotype D (7.4%) (p < 0.001). On the other hand, considering the samples with mutations only in positions G1896A and/or G1899A (PC), the frequency was higher in genotype D (75.8%) than in genotype A (6.9%) (p < 0.001). Interestingly, HBV DNA was lower than 2000 IU/mL especially when both BCP/PC mutations were present (p < 0.001) or when only PC mutations were detected (p = 0.047), reinforcing their role in viral replication.

Phylogeography of hepatitis B virus: The role of Portugal in the early dissemination of HBV worldwide

In Portugal, the genetic diversity, origin of HBV and the Portuguese role in the dissemination of HBV worldwide were never investigated. In this work, we studied the epidemic history and transmission dynamics of HBV genotypes that are endemic in Portugal. HBV pol gene was sequenced from 130 patients followed in Lisbon. HBV genotype A was the most prevalent (n = 54, 41.5%), followed by D (n = 44, 33.8%), and E (n = 32, 24.6%). Spatio-temporal evolutionary dynamics was reconstructed in BEAST using a Bayesian Markov Chain Monte Carlo method, with a GTR nucleotide substitution model, an uncorrelated lognormal relaxed molecular clock model, a Bayesian skyline plot, and a continuous diffusion model. HBV subgenotype D4 was the first to be introduced in Portugal around 1857 (HPD 95% 1699-1931) followed by D3 and A2 a few decades later. HBV genotype E and subgenotype A1 were introduced in Portugal later, almost simultaneously. Our results indicate a very important role of Portugal in the exportation of subgenotypes D4 and A2 to Brazil and Cape Verde, respectively, in the beginning of the XX century. This work clarifies the epidemiological history of HBV in Portugal and provides new insights in the early and global epidemic history of this virus.

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.

Hepatotropic viruses (hepatitis A, B, C, D and E) in a rural Brazilian population: prevalence, genotypes, risk factors and vaccination

BACKGROUND

People living in settlement projects represent an emergent rural population in Brazil. Data on their health is scarce and there are no data on viral hepatitis in this population. This study investigated the epidemiology of viral hepatitis A-E in residents of settlement projects in central Brazil.

METHODS

During 2011 and 2012, 923 people living in rural settlements in central Brazil were interviewed and tested to estimate the prevalence of exposure to viral hepatitis A-E, to identify the circulating hepatitis B virus (HBV)/hepatitis C virus (HCV) genotypes and risk factors for HBV exposure and to evaluate adherence to the hepatitis B vaccination series.

RESULTS

Overall, 85.9, 3.9, 0.4 and 17.3% of individuals showed evidence of exposure to hepatitis A virus (HAV), hepatitis E virus, HCV and HBV, respectively. Among HBV-DNA positive samples (n=8), subgenotypes A1 (n=3) and A2 (n=1) and genotype D/subgenotype D3 (n=4) were identified. Hepatitis D virus superinfection was detected in 0/16 HBsAg-positive participants. A total of 229 individuals showed serological evidence of HBV vaccination. In total, 442 settlers were eligible for vaccination, but only 150 individuals completed the vaccine series. All anti-HCV-positive samples (n=4) were also HCV-RNA positive and identified as subtype 1a.

CONCLUSIONS

The intermediate endemicity of HAV, the higher prevalence of HBV exposure compared with urban areas and the low compliance with HBV vaccination requires preventive measures focused on rural populations, emphasizing the need for HAV and HBV vaccination.

Evolutionary history of hepatitis B virus genotype H

Hepatitis B virus genotype H (HBV-H) molecular evolution was studied by comparing all published whole-genome sequences. Bayesian coalescent analysis was performed to estimate phylogenetic relationships, time to the most recent common ancestor (tMRCA), and viral population dynamics along the time. Phylogenetic tree demonstrated two main clades or lineages: HBV-H I (with sequences from Central and North America) and HBV-H II (with sequences from North and South America, and Asia). HBV-H II had more genome sequences (n = 26; 83.9%), including one specific subclade with all sequences outside of the Americas. Overall HBV-H tMRCA dated back to 1933 (95% highest posterior density interval [HPD 95%]: 1875-1957) with a very probable origin in Mexico and posterior dissemination to other American and Asian countries. The temporal analysis demonstrated that HBV-H I spread only in Mexico and the neighbor country of Nicaragua probably in the 1960s to the 1970s (1968; HPD 95%: 1908-1981), while HBV-II disseminated to other American and Asian countries around one decade later (1977; HPD 95%: 1925-1985). The phylogeographic analysis reinforced the Mexican origin of this genotype. The whole HBV-H population increased from the 1980s to the 2000s. In conclusion, HBV-H has two main lineages with a common origin in Mexico approximately nine decades ago.

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.

Hepatitis B: changes in epidemiological features of Afro-descendant communities in Central Brazil

Hepatitis B virus (HBV) infection is still a concern in vulnerable populations. In a study performed by our team in 1999–2003 in two Afro-Brazilian communities, Furnas dos Dionísios (FD) and São Benedito (SB), high prevalence rates of HBV exposure (42.7% and 16.0%, respectively), high susceptibility to HBV (55.3% and 63.0%) and low HBV vaccination like profile rates (2.0% and 21.0%) were observed. In 2015–2016, we reassessed HBV epidemiological and molecular features in these two communities to verify the impact of health actions adopted in the last years. The prevalence rate of HBV exposure among the enrolled 331 subjects was 35.3% in FD and 21.8% in SB. HBV chronic infection (5.8% in FD, 4.9% in SB) remained high. The rate of HBV vaccination like profile increased from 10.7% to 43.5% (2.0% to 45.9% in FD, 21.0% to 39.5% in SB) while susceptible subjects declined from 58.9% to 26.3% (55.3% to 18.8% in FD, 63.0% to 38.7% in SB). Among 18 HBsAg positive samples, 13 were successfully sequenced (pre-S/S region). Phylogenetic analyses showed that all isolates belong to HBV subgenotype A1, clustering within the Asian-American clade. Despite the maintenance of high prevalence rate of HBV exposure over these 13 years of surveillance, significant improvements were observed, reinforcing the importance of facilitated HBV vaccination to difficult-to-access population to close gaps in prevention.

Hepatitis B viremia in HIV-coinfected individuals under antiretroviral therapy

BACKGROUND

Antiretroviral therapy (ART) has decreased AIDS incidence and mortality, rendering comorbidities, such as hepatitis B more relevant for people living with human immunodeficiency virus (HIV). Since antiretroviral drugs may also inhibit hepatitis B virus (HBV) replication, analyzing the impact of ART on management of hepatitis B in this population is important.

OBJECTIVE

To assess HBV viremia among HIV/HBV coinfected individuals on ART and its associated factors.

METHOD

For this cross-sectional study, HIV/HBV-coinfected individuals, aged over 18 years, who were on ART for over six months and receiving care at an outpatient clinic in São Paulo were recruited. Sociodemographic characteristics, information about viral exposure, clinical and laboratory data, including evaluation of liver fibrosis were obtained. Plasma HBV DNA was measured by polymerase chain reaction. Viral genome sequencing was conducted for genotyping and identification of drug resistance-conferring mutations if viral load exceeded 900 IU/mL.

RESULTS

Out of 2,946 patients who attended the clinic in 2015, 83 were eligible and 56 evaluated. Plasma HBV DNA was detected in 16 (28.6%) (95% CI: 18.0-41.3%), all on lamivudine and tenofovir treatment. HBV DNA detection was associated with lower education (p = 0.015), higher international normalized ratios (p = 0.045), history of an AIDS-defining illness [OR: 3.43 (95% CI: 1.10-11.50)], and HBeAg detection [OR: 6.60 (95% CI: 1.84-23.6)]. In contrast, a last CD4+ count above 500 cells/mm3 in the year prior to inclusion [OR: 0.18 (95% CI: 0.04-0.71)] and detection of anti-HBe [OR: 0.21 (95% CI: 0.04-0.99)] were negatively associated. Patients with HBV DNA above 900 IU/mL were infected with subgenotypes A1 (n = 3) and D2 (n = 1), and exhibited viral mutations associated with total resistance to lamivudine and partial resistance to entecavir.

CONCLUSIONS

Despite being on ART, a significant proportion of HIV/HBV-coinfected individuals present HBV viremia. Characterization of factors that are associated with this finding may help professionals provide better management to these patients.

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.

Reconstruction of the spatial and temporal dynamics of hepatitis B virus genotype D in the Americas

Hepatitis B virus (HBV) genotype D (HBV/D) is globally widespread, and ten subgenotypes (D1 to D10) showing distinct geographic distributions have been described to date. The evolutionary history of HBV/D and its subgenotypes, for which few complete genome sequences are available, in the Americas is not well understood. The main objective of the current study was to determine the full-length genomic sequences of HBV/D isolates from Brazil and frequency, origin and spread of HBV/D subgenotypes in the Americas. Complete HBV/D genomes isolated from 39 Brazilian patients infected with subgenotypes D1 (n = 1), D2 (n = 10), D3 (n = 27), and D4 (n = 1) were sequenced and analyzed together with reference sequences using the Bayesian coalescent and phylogeographic framework. A search for HBV/D sequences available in GenBank revealed 209 complete and 926 partial genomes from American countries (Argentina, Brazil, Canada, Chile, Colombia, Cuba, Haiti, Martinique, Mexico, USA and Venezuela), with the major circulating subgenotypes identified as D1 (26%), D2 (17%), D3 (36%), D4 (21%), and D7 (1%) within the continent. The detailed evolutionary history of HBV/D in the Americas was investigated by using different evolutionary time scales. Spatiotemporal reconstruction analyses using short-term substitution rates suggested times of the most recent common ancestor for the American HBV/D subgenotypes coincident with mass migratory movements to Americas during the 19^th and 20^th centuries. In particular, significant linkages between Argentina and Syria (D1), Brazil and Central/Eastern Europe (D2), USA and India (D2), and Brazil and Southern Europe (D3) were estimated, consistent with historical and epidemiological data.

Molecular epidemiology of hepatitis B virus in Paraguay

Hepatitis B virus (HBV) infection is a leading cause of severe chronic liver disease worldwide. The HBV epidemiology in Latin American countries is complex and the data is still scanty and fragmentary. The aim of this study was to investigate the distribution of HBV genotypes in Paraguay and to estimate the viral population dynamic and spread pattern of the main phylogenetic group. To this end, partial and complete genome sequences were obtained from 60 blood donor candidates and analysed by phylogenetic and Bayesian phylodynamic approaches. The phylogenetic analysis based on sequences of partial Polymerase/Pre-S1 overlapping region showed a predominance of the Native American subgenotype F4 (81.7%), the presence of the European subgenotypes A2 (1.7%) and D3 (8.3%), the African subgenotype A1 (3, 5%) and the Asian subgenotypes B2 (1.7%) and C2 (1.7%). The distribution of HBV genotypes was in accordance with the ethnic composition of the population. The phylogeographic analysis of subgenotype F4 complete genomes suggests that this lineage emerged and spread in the last 300 years. Paraguay was the most probable location of the common ancestor. The lineage diverged into two main clades and spread to neighbor regions, mainly Bolivia and Northwest Argentina, and Buenos Aires. The phylogeny showed a scanty geographical structure and a complex migratory pattern. In conclusion, the HBV genotypes circulating in Paraguay reflect the ethnic origin of the population. The distribution of genotypes and the phylogeographic reconstruction showed the impact of both global and local migrations in shaping the HBV molecular epidemiology in the region.

High Prevalence of Hepatitis B Subgenotype D4 in Northeast Brazil: an Ancient Relic from African Continent?

INTRODUCTION

Hepatitis B virus (HBV) infection leads to a chronic liver disease that is distributed worldwide. The characterization of HBV into genotypes/subgenotypes is not only a mere procedure for distinguishing different HBV strains around the world because determining their geographic distribution is crucial to understanding their spread across the world.

MATERIAL AND METHODS

We characterized different HBV genotypes and subgenotypes in five municipalities located in northeastern Maranhão, in the Brazilian north Atlantic coast. 92 HBsAg-positive individuals were submitted to PCR (polymerase chain reaction). Fifty samples were sequenced using automated Sanger sequencing and classified by phylogenetic methods.

RESULTS

Subgenotypes D4 and A1 were found in 42 (84%) and eight (16%) samples, respectively. To our knowledge, this is the first study to describe a high frequency of subgenotype D4 in any population. Subgenotype A1 is frequently found across Brazil, but D4 has been rarely detected and only in a few Brazilian states. This study shows the characterization of HBV subgenotypes from a population based study in the state of Maranhão, particularly in populations that do not have frequent contact with populations from other regions of the world.

CONCLUSION

Our findings showed a HBV subgenotype profile that probably reflect the viruses that were brought with the slave trade from Africa to Maranhão. This study also reinforces the need to evaluate the status of HBV dispersion not only in large urban centers, but also in the hinterland, to enable the implementation of effective control and treatment measures.

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.

Hepatitis D infection in Brazil: Prevalence and geographical distribution of anti-Delta antibody

In Brazil, the Amazon Basin is endemic for hepatitis D virus (HDV) infection; however, studies in other regions of the country are scarce. This study aims to map the seroepidemiological situation of anti-Delta antibodies in chronic hepatitis B carriers in all five Brazilian geographic regions. Serum samples from 1240 HBsAg positive individuals (55.4% men; mean age 43.1 ± 13.4 years) from 24 of 26 Brazilian states were tested for the presence of anti-Delta antibodies using a commercial immunoassay. Anti-Delta antibodies were detected in 40 samples (3.2%; 52.5% female; mean age of 38.1 ± 13.8 years). Age less than 20 years was significantly associated with anti-HDV positivity (P < 0.001). The distribution of anti-Delta differed markedly in the diverse regions of the country. The highest prevalence of anti-HDV was found in the North (8.5%; P < 0.001), followed by Central West (2.5%), Southeast (1.7%), Northeast (0.8%), and South (0.0%). Anti-Delta antibodies were detected in 12 states, but more than 60% of the positive cases were observed in two states, Amazonas and Acre, located in the western portion of the Amazon region. The overall HDV prevalence of 3.2% emphasizes that HDV is far from being a disease under control in Brazil. Despite the low HDV prevalence in non-endemic regions, this infection persists as a major concern in two states (Acre and Amazonas) in the north of the country, indicating that a continuous epidemiological surveillance program should be implemented in all Brazilian regions.

Prevalence of occult hepatitis B in a population from the Brazilian Amazon region

In the present study, we evaluated the prevalence of occult hepatitis B (OBI) in a population from the Brazilian Amazon region, identify circulating genotypes, and mutations in the S gene. One hundred eighty-one patients with negative serology for HBsAg and anti-HBs and positive serology for anti-HBc participated in the study. Detection of viral DNA, genotyping by sequencing, and analysis of nucleotide sequences to detect possible mutations were performed. HBV DNA was detected in 14.36% of the patients. Genotyping revealed genotype A in 88.46% of HBV DNA-positive subjects, with subgenotype A1 being the most prevalent (78.26%) followed by subgenotype A2 (21.74%). Genotype F was detected in 11.54% (all of them subgenotype F2). Amino acid substitutions were observed in the amplified S gene in individuals with OBI compared to HBsAg-positive individuals (evident infection). In conclusion, the results show a high prevalence of OBI in the population studied, with a pattern of genotypes A and F that circulate in the Brazilian Amazon region. Amino acid substitutions were detected in part of the S gene in patients with OBI. Further studies on the molecular epidemiology of HBV in this region are important to identify patients considered healthy but who are potential transmitters of the disease.

Risk factors for hepatitis B transmission in South Brazil

BACKGROUND

Hepatitis B virus (HBV) infection is a major public health problem in Brazil. Several risk factors are involved in HBV infection and their identification by a rational and essential approach is required to prevent the transmission of this infection in Brazil.

OBJECTIVES

To evaluate risk factors associated with HBV infection in South Brazil.

METHODS

A total of 260 patients with HBV and 260 controls from Caxias do Sul (state of Rio Grande do Sul, Brazil) participated in this study. All participants were given a standard questionnaire to yield the sociodemographic information and to identify HBV risk factors. HBV infection was detected by HBsAg test in all participants.

FINDINGS

HBV infection in these cases was strongly associated with history of a family member HBV-infected, mainly mother [odds ratio (OR) = 4.86; 95% confidence intervals (CI): 1.69-13.91], father (OR = 5.28; 95% CI: 1.58-17.71), and/or siblings (OR = 22.16; 95% CI: 9.39-52.25); sharing personal objects (OR = 1.40; 95% CI: 1.37-2.38); and having history of blood transfusion (OR = 2.05; 95% CI: 1.10-2.84).

CONCLUSIONS

HBV infection was strongly associated with having a family member infected with hepatitis B, sharing personal objects, and having history of blood transfusion.

Epidemiological and molecular analysis of hepatitis B virus infection in manicurists in Central Brazil

The aim of this study was to investigate the serological and molecular prevalence of hepatitis B virus (HBV) infection in 514 manicurists/pedicurists and identify the risk factors related with this infection. Samples were tested for HBV serological markers, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA). Anti-HBc-positive samples were tested to investigate occult hepatitis B by PCR. HBsAg-positive samples were genotyped and the viral loads of HBV-DNA positive samples were quantified. The overall HBV prevalence was 5.6% (29/514) and of HBsAg was 0.4% (2/514). One case of occult hepatitis B was found. The genotypes A1 and F2 were identified in two HBsAg-positive samples. Low level of education, not being born in the State of Mato Grosso do Sul and working in the central region of the city were associated with the HBV infection. No single manicurist/pedicurist was infected by HCV or HIV. These findings suggest that despite the exposure to blood contact, this occupation was not associated to an increased risk of acquiring HBV, HCV, and HIV infections.

Mutations associated with drug resistance and prevalence of vaccine escape mutations in patients with chronic hepatitis B infection

The Brazilian public health system (SUS) has provided antiviral drugs for chronic hepatitis B treatment for over 10 years, but a system for monitoring for drug-related resistance mutations is not available. Determine the presence of HBV mutations associated with resistance to nucleos(t)ide analogs among 81 patients with chronic HBV infection in Salvador-BA-Brazil. HBV-DNA was PCR amplified with primers deduced from the rt domain at the HBV P gene, the sequence extended 1032 bp (from amino acid 1 to 344-rt domain). Those sequences were submitted to the HBV drug resistance database to retrieve each mutation according to the genotype. HBV genotype A1 (85.2%) was the most prevalent, followed by genotype A2 (4.9%), F (6.2%), and C1, D2, and D4 (1.2% each). Six patients (7%) exhibited resistance mutations to LAM, ETV, and TDF: two with patterns L180M + M204V and four with other different patterns: L80I + L180M + M204I; L80V + L180M + M204V; M204I; A194T. All of these mutations were present in patients with genotype A (four A1 and two A2). In addition, four mutations in gene S (three cases with the sI195M mutation and one with the W196L mutation), were detected, corresponding to a rate of 6% of vaccine escape mutations. Althougth the small sample size, an association was found between the occurrence of HBV resistance mutations and HBeAg positivity, co-infection with HIV and a history of treatment for HBV and/or HIV.

Nationwide overview of the distribution of hepatitis B virus genotypes in Brazil: a 1000-sample multicentre study

The influence of hepatitis B virus (HBV) genotypes in the natural history of the disease and its response to antiviral treatment have been addressed in many studies. In Brazil, studies on HBV genotype circulation have been restricted to specific population groups and states. Here, we have conducted a nationwide multicentre study with an unprecedented sample size representing all Brazilian regions in an effort to better understand the viral variants of HBV circulating among chronic carriers. Seven HBV genotypes were found circulating in Brazil. Overall, HBV/A was the most prevalent, identified in 589 (58.7 %) samples, followed by HBV/D (23.4 %) and HBV/F (11.3 %). Genotypes E, G, C and B were found in a minor proportion. The distribution of the genotypes differed markedly from the north to the south of the country. While HBV/A was the most prevalent in the North (71.6 %) and Northeast (65.0 %) regions, HBV/D was found in 78.9 % of the specimens analysed in the South region. HBV/F was the second most prevalent genotype in the Northeast region (23.5 %). It was detected in low proportions (7 to 10 %) in the North, Central-West and Southeast regions, and in only one sample in the South region. HBV/E was detected in all regions except in the South, while monoinfection with HBV/G was found countrywide, with the exception of Central-West states. Our sampling covered 24 of the 26 Brazilian states and the Federal District and is the first report of genotype distribution in seven states. This nationwide study provides the most complete overview of HBV genotype distribution in Brazil to date and reflects the origin and plurality of the Brazilian population.

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

Hepatitis B virus (HBV) is distributed worldwide, with geographical variations regarding prevalence of the different genotypes. The aim of this study was to determine the HBV genotypes and subgenotypes circulating in Southeast Brazil and compare the genetic sequences found with HBV sequences previously described in the world. Sequences from 166 chronic HBV carriers were analyzed using the fragment constituted by 1306 base pairs comprising surface and polymerase regions of the HBV genome. The sequences obtained were submitted to phylogenetic analysis. HBV subgenotypes A1, A2, D1-D4, F2a, and F4 were found. HBV genotype D was the most frequent, found in 99 patients (58.4%). Within this group, subgenotype D3 was the most prevalent, in 73 patients (42.9%). HBV genotype A was identified in 58 (36%) patients, subgenotype A1, in 48 (29.8%) subjects. Genotype F was identified in 9 (5.4%). According to the phylogenetic analysis, the sequences found were grouped with sequences from Europe, Asia and Middle East (subgenotypes D1, D2, D3) and sequences from Latin America and Africa (subgenotype A1). HBV D3 grouped in different clusters inside D3 clade, several of them with sequences isolated in Italy. We also identified eight families whose relatives were infected with the same HBV subgenotype, most with high similarity between sequences. In conclusion, the distribution of the HBV sequences obtained interweaved with sequences from other continents, corresponding to regions from where many immigrants came to this region, in accordance to the hypothesis that the HBV detected over there were brought during the colonization times.

Identification of a new hepatitis B virus recombinant D2/D3 in the city of São Paulo, Brazil

Two hundred forty million people are chronically infected with hepatitis B virus (HBV) worldwide. The rise of globalization has facilitated the emergence of novel HBV recombinants and genotypes. We evaluated HBV genotypes and recombinants, mutations associated with resistance to antivirals (AVs), progression of hepatic illness, and inefficient hepatitis B vaccination responses in chronically infected individuals in the city of São Paulo, Brazil. Forty-five full-length and 24 partial-length sequences were obtained. The genotype distribution was as follows: A (66.7%), D (15.9%), F (11.6%) and C (4.3%). We describe a new recombinant (D2/D3), confirmed through next-generation sequencing (NGS) and reconstruction of the quasispecies sequences in silico. Primary resistance and major vaccine escape mutations were not found. We did, however, find mutations in the S region that might may be related to HBV antigenicity changes, as well as Pre-S deletions. The precore/core mutations A1762T + G1764A (40.9%) were found mostly in genotypes A and D, and G1896A (29.55%) was more frequent in genotype D than in genotype A. The genotypic distribution reflects the history of Brazilian immigration. This is the first description of recombination between genotypes D2 and D3 in Brazil. It is also the first confirmation through NGS and reconstruction of the quasispecies in silico. However, little is known about the response to treatment of recombinants. This demonstrates the need for molecular epidemiology studies involving the analysis of full-length HBV sequences.

Molecular epidemiology of hepatitis B virus in Misiones, Argentina

Hepatitis B virus (HBV) infection is a major public health problem worldwide. The aims of this study were to describe the molecular epidemiology of HBV in the Province of Misiones, Argentina and estimate the phylodynamic of the main groups in a Bayesian coalescent framework. To this end, partial or complete genome sequences were obtained from 52 blood donor candidates. The phylogenetic analysis based on partial sequences of S/P region showed a predominance of genotype D (65.4%), followed by genotype F (30.8%) and genotype A as a minority (3.8%). At subgenotype level, the circulation of subgenotypes D3 (42.3%), D2 (13.5%), F1b (11.5%) and F4 (9.6%) was mainly identified. The Bayesian coalescent analysis of 29 complete genome sequences for the main groups revealed that the subgenotypes D2 and D3 had several introductions to the region, with ancestors dating back from 1921 to 1969 and diversification events until the late '70s. The genotype F in Misiones has a more recent history; subgenotype F4 isolates were intermixed with sequences from Argentina and neighboring countries and only one significant cluster dated back in 1994 was observed. Subgenotype F1b isolates exhibited low genetic distance and formed a closely related monophyletic cluster, suggesting a very recent introduction. In conclusion, the phylogenetic and coalescent analyses showed that the European genotype D has a higher circulation, a longer history of diversification and may be responsible for the largest proportion of chronic HBV infections in the Province of Misiones. Genotype F, especially subgenotype F1b, had a more recent introduction and its diversification in the last 20years might be related to its involvement in new transmission events.

High prevalence of HBV/A1 subgenotype in native south Americans may be explained by recent economic developments in the Amazon

Native American populations present the highest prevalence of Hepatitis B Virus (HBV) infection in the Americas, which may be associated to severe disease outcomes. Ten HBV genotypes (A–J) have been described, displaying a remarkable geographic structure, which most likely reflects historic patterns of human migrations. In this study, we characterize the HBV strains circulating in a historical sample of Native South Americans to characterize the historical viral dynamics in this population. The sample consisted of 1070 individuals belonging to 38 populations collected between 1965 and 1997. Presence of HBV DNA was checked by quantitative real-time PCR, and determination of HBV genotypes and subgenotypes was performed through sequencing and phylogenetic analysis of a fragment including part of HBsAg and Pol coding regions (S/Pol). A Bayesian Skyline Plot analysis was performed to compare the viral population dynamics of HBV/A1 strains found in Native Americans and in the general Brazilian population. A total of 109 individuals were positive for HBV DNA (~ 10%), and 70 samples were successfully sequenced and genotyped. Subgenotype A1 (HBV/A1), related to African populations and the African slave trade, was the most prevalent (66–94%). The Skyline Plot analysis showed a marked population expansion of HBV/A1 in Native Americans occurring more recently (1945–1965) than in the general Brazilian population. Our results suggest that historic processes that contributed to formation of HBV/A1 circulating in Native American are related with more recent migratory waves towards the Amazon basin, which generated a different viral dynamics in this region.

Hepatitis B Virus Genotype D Isolates Circulating in Chapecó, Southern Brazil, Originate from Italy

Hepatitis B virus genotype A1 (HBV/A1), of African origin, is the most prevalent genotype in Brazil, while HBV/F predominates in the other South American countries. However, HBV/D is the most common in the three states of southern Brazil, where ‘islands’ of elevated prevalence, as Chapecó and other cities, have been described. In this study, 202 HBV chronic carriers attending in 2013 the viral hepatitis ambulatory of Chapecó, were investigated. In comparison with previous studies performed in the same ambulatory, a rapid aging of the HBV infected population was observed (mean age of the newly diagnosed patients increasing from 29.9 ± 10.3 years in 1996 to 44.4 ± 13.3 years in 2013), probably due to a singular vaccination schedule at Chapecó that included not only children but also adolescents. Phylogenetic and BLAST analyses (S region) classified 91 HBV isolates into genotypes A (n = 3) and D (n = 88). The majority of HBV/D isolates were closely related to D3 sequences. To understand the reasons for the absence or near absence of genotypes A and F, and how HBV/D was introduced in the south of Brazil, HBV/D infected patients were inquired about their genealogical and geographical origins. Forty-three (52%) patients have their four grandparents of Italian origin, vs. seven (8%) who have their four grandparents of Brazilian origin. At all, 65 out of 83 (78%) patients had at least one grandparent originating from Italy. Taking into consideration the fact that Italy is one of the few countries where subgenotype D3 is predominant, the results strongly suggested that HBV/D was introduced in Brazil through Italian immigration which culminated between 1870 and 1920.

Full-genome sequences of hepatitis B virus subgenotype D3 isolates from the Brazilian Amazon Region

The Brazilian Amazon Region is a highly endemic area for hepatitis B virus (HBV). However, little is known regarding the genetic variability of the strains circulating in this geographical region. Here, we describe the first full-length genomes of HBV isolated in the Brazilian Amazon Region; these genomes are also the first complete HBV subgenotype D3 genomes reported for Brazil. The genomes of the five Brazilian isolates were all 3,182 base pairs in length and the isolates were classified as belonging to subgenotype D3, subtypes ayw2 (n = 3) and ayw3 (n = 2). Phylogenetic analysis suggested that the Brazilian sequences are not likely to be closely related to European D3 sequences. Such results will contribute to further epidemiological and evolutionary studies of HBV.

Hepatitis B virus subgenotype A1: evolutionary relationships between Brazilian, African and Asian isolates

Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

Hepatitis B virus infection in Latin America: A genomic medicine approach

Hepatitis B virus (HBV) infection is the leading cause of severe chronic liver disease. This article provides a critical view of the importance of genomic medicine for the study of HBV infection and its clinical outcomes in Latin America. Three levels of evolutionary adaptation may correlate with the clinical outcomes of HBV infection. Infections in Latin America are predominantly of genotype H in Mexico and genotype F in Central and South America; these strains have historically circulated among the indigenous population. Both genotypes appear to be linked to a benign course of disease among the native and mestizo Mexicans and native South Americans. In contrast, genotypes F, A and D are common in acute and chronic infections among mestizos with Caucasian ancestry. Hepatocellular carcinoma is rare in Mexicans, but it has been associated with genotype F1b among Argentineans. This observation illustrates the significance of ascertaining the genetic and environmental factors involved in the development of HBV-related liver disease in Latin America, which contrast with those reported in other regions of the world.

Seroprevalence of Hepatitis B and C markers at the population level in the municipality of Caxias do Sul, southern Brazil

Chronic viral hepatitis are main public health problems worldwide. Data about the seroprevalence to Hepatitis B and C viruses (HBV e HCV) at the population level are scarce on Brazil and especially for the Southern region of the country. The seroprevalence to HBV and HBC antigens was evaluated on a large portion of the population of the municipality of Caxias do Sul (427,858 inhabitants), Brazil. A total of 60,604 individual serum samples collected from 2008 to 2011 were screened for HBV surface antigen (HBsAg) and for antibodies against HBsAg; anti HCV antibodies were measured by ELISA (Enzyme Linked Immunosorbent Assay). Overall, 1.63% of the individuals were positive for HBsAg and 1.43% showed seropositivity to HCV. From the total, 31,749 samples were analyzed for HBsAg and 28,855 for HCV. For HBsAg, 519 samples showed positive (1.63%) while the results for 37 patients (0.12%) remained inconclusive. For the anti-HCV test, 412 individuals (1.43%) showed positive. From the positive samples for HBsAg 216 (50.6%) were from male individuals whereas for anti-HCV the seroprevalence was slightly higher for females 216 (52.4%). The higher prevalence for both hepatitis viruses were found among individuals at the age group of 40 to 59 years and the lower levels of positivity for both HBV and HBC were among children and teenagers.

Occult hepatitis B virus infection among blood donors from the Brazilian Amazon: implications for transfusion policy

BACKGROUND

Brazil requires the performance of both a test for hepatitis B surface antigen (HBsAg) and a test for antibodies to the core of hepatitis B for blood donor screening. Blood centres in regions of high HBV endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-HBc reactivity. We evaluated the potential infectivity of donations positive for anti-HBc in search of a rational approach for the handling of these collections.

STUDY DESIGN AND METHODS

We tested anti-HBc reactive blood donations from the state of Amazonas for the presence of HBV DNA and for titres of anti-HBs. The study population consists of village-based donors from the interior of Amazonas state.

RESULTS

Among 3600 donations, 799 were anti-HBc reactive (22·2%). We were able to perform real-time PCR for the HBV S gene on specimens from 291 of these donors. Eight of these samples were negative for HBsAg and positive for HBV DNA and were defined as occult B virus infections (2·7%). Six of those eight specimens had anti-HBs titres above 100 mIU/ml, indicating the concomitant presence of the virus with high antibody titres.

CONCLUSION

A small proportion of anti-HBc reactive donors carry HBV DNA and anti-HBs testing is not useful for predicting viremia on them. This finding indicates the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. Sensitive HBV DNA nucleic acid testing may provide another level of safety, allowing eventual use of anti-HBc reactive units in critical situations.

Phylogeography and evolutionary history of hepatitis B virus genotype F in Brazil

Background

Hepatitis B virus (HBV) genotype F (HBV/F) is considered to be indigenous to the Americas, but its emergence and spread in the continent remain unknown. Previously, only two HBV/F complete genome sequences from Brazil were available, limiting the contribution of Brazilian isolates to the phylogenetic studies of HBV/F. The present study was carried out to assess the proportion and geographic distributions of HBV/F subgenotypes in Brazil, to determine the full-length genomic sequences of HBV/F isolates from different Brazilian geographic regions, and to investigate the detailed evolutionary history and phylogeography of HBV/F in Brazil.

Methods

Complete HBV/F genomes isolated from 12 Brazilian patients, representing the HBV/F subgenotypes circulating in Brazil, were sequenced and analyzed together with sequences retrieved from GenBank, using the Bayesian coalescent and phylogeographic framework.

Results

Phylogenetic analysis using all Brazilian HBV/F S-gene sequences available in GenBank showed that HBV/F2a is found at higher frequencies countrywide and corresponds to all sequences isolated in the Brazilian Amazon Basin. In addition, the evolutionary analysis using complete genome sequences estimated an older median ancestral age for the Brazilian HBV/F2a compared to the Brazilian HBV/F1b and HBV/F4 subgenotypes, suggesting that HBV/F2a represents the original native HBV of Brazil. The phylogeographic patterns suggested a north-to-south flow of HBV/F2a from Venezuela to Brazil, whereas HBV/F1b and HBV/F4 strains appeared to have spread from Argentina to Brazil.

Conclusions

This study suggests a plausible route of introduction of HBV/F subgenotypes in Brazil and demonstrates the usefulness of recently developed computational tools for investigating the evolutionary history of HBV.

Distribution of HBV genotypes in Latin America

Approximately 2 billion people worldwide are infected with HBV, and 350 million people are chronic carriers. HBV is classified into nine genotypes (A to I). Genotype F is the most prevalent in the Spanish-speaking countries and in the Amerindian population in South America. HBV genotype F was primarily found in indigenous populations from South America and is divided into four subgenotypes (F1 to F4). Subgenotype F1 is further divided into F1a (found in Costa Rica and El Salvador) and F1b (found in in Alaska, Argentina and Chile). Subgenotypes F2 and F3 cocirculate in the north of South America: F2a is found in Brazil and Venezuela, F2b is described only in Venezuela, F3 is frequent in Colombia, Venezuela and Panama, and F4 is reported from the central and south areas of South America, including Bolivia, Argentina and southern Brazil. HBV genotypes and subgenotypes have distinct geographical distributions. It is currently under discussion whether they are associated with different prognoses, considering the patterns of severity of liver diseases in various populations. Furthermore, global human migrations affect the pattern of genotype distribution, introducing genotypes differing from those found in the original inhabitants.

Phylogenetic analysis and subgenotypic distribution of the hepatitis B virus in Recife, Brazil

The analysis of the genomes of the hepatitis B virus in human hosts identifies phylogenetic variants called viral genotypes. Indeed, clinical and epidemiological observations suggest that differences in viral genotypes lead to distinct biological and clinical behaviors. The aim of this study was to evaluate the subgenotypic distribution and to conduct a phylogenetic analysis by Bayesian method of the hepatitis B virus (HBV) in patients from Recife, Brazil. From July 2009 to December 2010, 60 HBV infected patients were examined, 39 (65%) were males, whose mean age was 50years old. 33 (55%) were genotyped by obtaining and amplifying a 1306bp fragment comprising part of the DNA polymerase and the surface antigen of the HBV. The sequencing was performed on an ABI 3500 Automatic Sequencer and the consensus sequences were obtained by aligning both the sequenced strands (clockwise and anti-clockwise) using SEQUENCHER software. Phylogenetic analysis was conducted using the Markov Chain Monte Carlo simulation implemented by Bayesian evolutionary method by sampling trees. The following subgenotypic distribution was observed: A1 (79%), F2a (12%), A2 (6%) and F4 (3%) as was that those identified as subgenotype A1 were in the same cluster in the phylogenetic tree. In this study, the majority of patients presented the A1 subgenotype from the same viral strain. As per the distribution in the phylogenetic tree by Bayesian method, possibly this subgenotype was in the genetic make-up of Africans brought in centuries past to Brazil as slaves.