High prevalence of occult hepatitis B virus genotype H infection among children with clinical hepatitis in west Mexico

Studies on the prevalence of infection with hepatitis B virus (HBV) among children are scarce in Latin American countries, especially in Mexico. This study was aimed to investigate the prevalence of HBV infection, occult hepatitis B infection (OBI) and HBV genotypes among children with clinical hepatitis. In total, 215 children with clinical hepatitis were evaluated for HBV infection. HBV serological markers and HBV DNA were analysed. OBI diagnosis and HBV genotyping was performed. HBV infection was found in 11.2% of children with clinical hepatitis. Among these HBV DNA positive-infected children, OBI was identified in 87.5% (n = 21/24) of the cases and 12.5% (n = 3/24) were positive for both HBV DNA and hepatitis B surface antigen. OBI was more frequent among children who had not been vaccinated against hepatitis B (p < 0.05) than in those who had been vaccinated. HBV genotype H was prevalent in 71% of the children followed by genotype G (8%) and genotype A (4%). In conclusion, OBI is common among Mexican children with clinical hepatitis and is associated with HBV genotype H. The results show the importance of the molecular diagnosis of HBV infection in Mexican paediatric patients with clinical hepatitis and emphasise the necessity of reinforcing hepatitis B vaccination in children.     

A type-specific nested PCR assay established and applied for investigation of HBV genotype and subgenotype in Chinese patients with chronic HBV infection

ABSTRACT: BACKGROUND: Many studies have suggested that hepatitis B virus (HBV) genotypes show not only geographical distribution and race specificity, but also are associated with disease progression and response to interferon treatment. The objective of this study was to develop a nested polymerase chain reaction (nPCR) assay for genotypes A-D and subgenotypes B1, B2, C1 and C2 of hepatitis B virus (HBV) and to investigate the distribution characteristics of HBV genotypes/subgenotype in China. METHODS: After redesigning the primers and optimizing the reaction conditions using common Taq polymerase, the sensitivity, specificity and reproducibility of the method were evaluated using plasmids and serum samples. In total, 642 serum samples from patients with chronic HBV infection were applied to investigate the distribution of HBV genotype and subgenotype in China. RESULTS: The genotype and subgenotype could be identified when the HBV DNA load of a sample was ≥10(2.3) IU/mL. For the 639 successfully genotyped samples, the sequencing results of 130 randomly selected samples (20.3%, 130/639) were consistent with those of the nPCR method. The present study showed that HBV genotype B (11.2%, 72/642), C (68.2%, 438/642) and D (7.2%, 46/642) were circulating in China, while genotype C was the dominant strain except for western region where genotype D was the prevalent strain. The main subgenotypes of genotypes B and C were B2 (87.5%, 63/72) and C2 (92.9%, 407/438), respectively. CONCLUSIONS: The low-cost nPCR method would be a useful tool for clinical and epidemiological investigation in the regions where genotypes A-D are predominant.     

Research on Hepatitis B virus Genotypes and Subgenotypes among Bai Nationality in Dali, Yunnan Province

To investigate the distribution of hepatitis B virus （HBV） genotypes and subgenotypes among the Bai nationality in Dali, a total of 100 serum samples from patients with chronic HBV-infection were collected for the detection of HBV genotypes and subgenotypes by genotype-specific primers and restriction fragment length polymorphism （RLFP）, respectively. Among the 100 samples, the proportions of genotype B, C and mixed genotype （B＋C） were 41%, 25% and 34%, respectively. All the genotype B strains belonged to subgenotype Ba In genotype C, 84% were Subgenotype Cs and 12% were subgenotype Ce. The distribution of genotypes B, C and B＋C showed no significant difference between male and female patients （P=0.182） and among the age groups of patients （P=0.812）. The rates of HBeAg/HBeAg positivity were no significantly different among genotypes B, genotype C and mixed genotype （B＋C） （P=0.077/P=0.663）. In Dali, genotypes B, B＋C and C existed among Bai nationality with chronic HBV-infection, and genotype B was the major genotype. Subgenotypes Ba and Cs were the predominant strains in patients with HBV genotype B/C infection. The most prominent characteristic was the higher prevalent rate of mixed genotype （B＋C） in patients.     

Research on hepatitis B virus genotypes and subgenotypes among Bai nationality in Dali, Yunnan Province

To investigate the distribution of hepatitis B virus (HBV) genotypes and subgenotypes among the Bai nationality in Dali, a total of 100 serum samples from patients with chronic HBV-infection were collected for the detection of HBV genotypes and subgenotypes by genotype-specific primers and restriction fragment length polymorphism (RLFP), respectively. Among the 100 samples, the proportions of genotype B, C and mixed genotype (B C) were 41%, 25% and 34%, respectively. All the genotype B strains belonged to subgenotype Ba. In genotype C, 84% were Subgenotype Cs and 12% were subgenotype Ce. The distribution of genotypes B, C and B C showed no significant difference between male and female patients (P=0.182) and among the age groups of patients (P=0.812). The rates of HBeAg/HBeAg positivity were no significantly different among genotypes B, genotype C and mixed genotype (B C) (P=0.077/P=0.663). In Dali, genotypes B, B C and C existed among Bai nationality with chronic HBV-infection, and genotype B was the major genotype. Subgenotypes Ba and Cs were the predominant strains in patients with HBV genotype B/C infection. The most prominent characteristic was the higher prevalent rate of mixed genotype (B C) in patients.     

青海省同德地区藏族人群乙型肝炎病毒基因型的探讨

青海省同德地区藏族人群经1980年、1986年、2000年及2004年乙型肝炎(HBV)血清学检测,其阳性率分别为33·22%、23·84%、17·84%及16·95%。初步认定同德地区藏族人群为乙型肝炎的高流行区。为探索该流行区乙肝病毒的生物学特性,对其基因型进行分析,以期为该地区制定HBV防治方案     

Prevalence of HBV genotypes among Egyptian hepatitis patients

Phylogenetic analysis has led to the classification of hepatitis B virus into eight genotypes, designated A to H. The genotypes have differences in biological properties and show heterogeneity in their global distribution. These attributes of the genotypes may account not only for differences in the prevalence of hepatitis B virus mutants in various geographic regions, but also makes them responsible for differences in the clinical outcome and response to antiviral treatment in different population groups. Africa is one of the highly endemic regions of HBV with five genotypes (A–E) identified. Almost all patients in the Mediterranean area are infected with genotype D. However, there is little information of genotype distribution in Egypt. A total of 140 Egyptian patients with hepatitis B surface antigen (HBsAg) positive were enrolled in this study. Of the 140 patients, only 100 patients were HBV DNA positive and only these were included in the study. They were classified into 20 patients with acute hepatitis (AH), 75 patients with chronic active hepatitis (CAH) and 5 patients with hepatocellular carcinoma (HCC). HBV genotypes were determined using INNO-LiPA methodology which is based on the reversed hybridization principle. This study showed that genotype D constituted 87% of the total infections (75 CAH cases, 7 AH cases and 5 HCC cases). The other 13% showed mixed infections of D/F. These findings show that the most prevalent genotype in Egypt is genotype D especially in CAH and HCC patients while the mixed type D/F is only encountered in AH.     

Epidemiology,Risk Factors and Genotypes of HBV in HIV-Infected Patients in the Northeast Region of Colombia: High Prevalence of Occult Hepatitis B and F3 Subgenotype Dominance

Introduction

Chronic hepatitis B virus (HBV) infection is an increasing cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected individuals. HIV-positive patients are commonly co-infected with HBV due to shared routes of transmission.

Objectives

Our aim was to determine the risk factors, prevalence, genotypes, and mutations of the Surface S gene of HBV, and occult hepatitis B infection (OBI) among patients infected with HIV in a northeastern Colombian city.

Methods

A cross-sectional study was conducted with 275 HIV-positive patients attending an outpatient clinic in Bucaramanga, Colombia during 2009–2010. Blood samples were collected and screened for serological markers of HBV (anti-HBs, anti-HBc and HBsAg) through ELISA assay. Regardless of their serological profile, all samples were tested for the HBV S gene by nested-PCR and HBV genotypes were determined by phylogenetic inference. Clinical records were used to examine demographic, clinical, virological, immunological and antiretroviral therapy (ART) variables of HIV infection.

Results

Participants were on average 37±11 years old and 65.1% male. The prevalence of HIV-HBV coinfection was 12% (95%CI 8.4–16.4) of which 3.3% had active HBV infection and 8.7% OBI. The prevalence of HIV-HBV coinfection was associated with AIDS stage and ART treatment. Sequence analysis identified genotype F, subgenotype F3 in 93.8% of patients and genotype A in 6.2% of patients. A C149R mutation, which may have resulted from failure in HBsAg detection, was found in one patient with OBI.

Conclusions

The present study found a high prevalence of HIV-HBV coinfection with an incidence of OBI 2.6-fold higher compared to active HBV infection. These findings suggest including HBV DNA testing to detect OBI in addition to screening for HBV serological markers in HIV patients.     

Genetic Diversity of the Hepatitis B Virus Strains in Cuba: Absence of West-African Genotypes despite the Transatlantic Slave Trade

Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV) strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutations of 172 Cuban HBsAg and HBV-DNA positive patients were determined by direct sequencing and phylogenetic analysis. Phylogenetic analysis of HBV S gene sequences showed a predominance of genotype A (92.4%), subgenotype A2 (84.9%) and A1 (7.6%). Genotype D (7.0%) and subgenotype C1 (0.6%) were also detected but typical (sub)genotypes of contemporary West-Africa (E, A3) were conspicuously absent. All genotype A, D, and C strains exhibited sequence characteristics of the adw2, ayw2, and adrq serotypes, respectively. Thirty-three (19.1%) patients showed single, double, or multiple point mutations inside the Major Hydrophilic domain associated with vaccine escape; eighteen (10.5%) patients had mutations in the T-cell epitope (amino acids 28-51), and there were another 111 point mutations downstream of the S gene. One patient had an HBV A1/A2 mixed infection. This first genetic study of Cuban HBV viruses revealed only strains that were interspersed with strains from particularly Europe, America, and Asia. The absence of genotype E supports previous hypotheses about an only recent introduction of this genotype into the general population in Africa. The presence of well-known vaccine escape (3.5%) and viral resistance mutants (2.9%) warrants strain surveillance to guide vaccination and treatment strategies.     

内蒙古地区乙型肝炎病毒的基因分型及临床意义

为了探讨乙型肝炎病毒在内蒙古地区的基因分型,为本地区乙型肝炎的临床治疗、病情进展和发病机制等方面研究提供有益的实验依据。2013年7月至2014年7月本研究在内蒙古自治区人民医院、内蒙古医科大学第一附属医院、通辽市医院的门诊及住院病例中随机选取已感染乙型肝炎病毒的253例。以荧光定量PCR法检测HBV基因分型和HBV病毒基因载量,Elisa法检测血清标志物HBeAg,全自动生化分析仪检测ALT、AST、TBA、TBIL和ALB。实验发现,内蒙古地区253例患者HBV基因分型结果以B型(49例,19.37%)、C型(188例,74.31%)为主,且C基因型显著多于B基因型(p<0.05);HBeAg阳性率为67.59%,且C基因型HBeAg阳性率高于B基因型;高载量病例中B型占31例(63.27%),而C型占162例(86.17%),C基因型组中HBV DNA载量显著高于B基因型组(p<0.01);B基因型与C基因型TBA、TBIL和ALB结果比较差异无统计学意义(p>0.05),但C基因型的ALT和AST这两项生化指标均显著高于B基因型组(p<0.05)。本研究结果初步说明,内蒙古地区HBV感染以B型和C型为主,尤以C型居多;且C型病毒的复制较活跃,致病力较强,HBV感染者更易转成严重肝病。     

Risk of vertical transmission of hepatitis B virus in Tunisia

The risk of vertical transmission of hepatitis B virus (HBV) varies with type of viral endemicity, degree of maternal infection and genomic characteristics of the virus. The aim of this study is to estimate this risk in Tunisia using serological and molecular methods to evaluate HBV replication, to determine viral genotypes and to detect presence of occult hepatitis in 2709 pregnant women. Serological markers were detected by ELISA methods, Genotype was determined by PCR-RFLP and occult hepatitis by nested-PCR. Four percent of women were positive for HBsAg; only 3% of them were also positive for HBeAg. Viral replication, over than 10(3) copies/ml, was detected in 61% of positive HBsAg patients. Three viral genotypes were detected: D (95%), B (3%) and A (3%). Occult hepatitis was detected in 4% of sera with "anti-HBc isolated" profile. In conclusion, the risk of vertical transmission of HBV exists in Tunisia. It increases by frequency of precore mutants, predominance of the genotype previously associated with high levels of replication and possibility of occult hepatitis B. These results show the importance of screening by serological HBV markers systematically during pregnancy with evaluation of viral replication in order to prevent vertical risk by efficient tools.     

黑龙江地区400例乙型肝炎病毒基因分型与耐药突变研究

目的:运用基因芯片技术分析黑龙江地区乙型肝炎病毒(HBV)基因型分布特征及基因耐药变异情况。方法:随机选择2012年11月至2015年11月本医院乙型肝炎患者血清样本400例,应用PCR-反向点杂交的基因芯片技术对样本血清中HBV基因型及常见4类抗病毒药物耐药相关的多个位点进行检测,并进行数据分析。结果:400例样本中基因型分布以C型为主占83.25%(333例),B型7.25%(29例)、D型0.25%(1例)及混合基因型2.75%(11例);耐药突变位点检出188例,总耐药率为45.19%,其中突变位点236T(4.61%)提示阿德福韦酯单项耐药,耐药率为5.82%(10例),与拉米夫定耐药相关的为126例,突变位点以rt204I和(rt180M+rt240V)为主,显著高于其他抗病毒类药物,耐药风险较高。结论:黑龙江地区乙型肝炎基因分型以C为主,B型和其它混合型较少,且更容易对拉米夫定产生耐药。     

Hepatitis B virus infection profile in hemodialysis patients in Central Brazil: prevalence, risk factors, and genotypes

Hemodialysis patients are at high risk for hepatitis B virus (HBV) infection. A survey was conducted in the hemodialysis population of the state of Goiás, Central Brazil, aiming to assess the prevalence of HBV infection, to analyse associated risk factors, and also to investigate HBV genotypes distribution. A total of 1095 patients were interviewed in 15 dialysis units. Serum samples were screened for HBV serological markers by enzyme-linked immunosorbent assay. Hepatitis B surface antigen (HBsAg) positive samples were tested for HBV DNA by polymerase chain reaction and genotyped by restriction fragment length polymorphism. Global HBV infection prevalence was 29.8% (95% CI: 27.1-32.5). Multivariate analysis of risk factors showed that male gender, length of time on hemodialysis, and blood transfusion before 1993 were associated with HBV positivity. HBV DNA was detected in 65.4% (17/26) of the HBsAg-positive samples. Thirteen of 17 HBV DNA positive samples were genotyped. Genotype D (61.5%) was predominant, followed by A (30.8%), while genotype F was detected in only one (7.7%) sample.     

Complex Genotype Mixtures Analyzed by Deep Sequencing in Two Different Regions of Hepatitis B Virus

This study assesses the presence and outcome of genotype mixtures in the polymerase/surface and X/preCore regions of the HBV genome in patients with chronic hepatitis B virus (HBV) infection. Thirty samples from ten chronic hepatitis B patients were included. The polymerase/surface and X/preCore regions were analyzed by deep sequencing (UDPS) in the first available sample at diagnosis, a pre-treatment sample, and a sample while under treatment. HBV genotype was determined by phylogenesis. Quasispecies complexity was evaluated by mutation frequency and nucleotide diversity. The polymerase/surface and X/preCore regions were validated for genotyping from 113 GenBank reference sequences. UDPS yielded a median of 10,960 sequences per sample (IQR 16,645) in the polymerase/surface region and 11_,595 sequences per sample (IQR 14,682) in X/preCore. Genotype mixtures were more common in X/preCore (90%) than in polymerase/surface (30%) (p<0.001). On X/preCore genotyping, all samples were genotype A, whereas polymerase/surface yielded genotypes A (80%), D (16.7%), and F (3.3%) (p = 0.036). Genotype changes in polymerase/surface were observed in four patients during natural quasispecies dynamics and in two patients during treatment. There were no genotype changes in X/preCore. Quasispecies complexity was higher in X/preCore than in polymerase/surface (p = 0.004).The results provide evidence of genotype mixtures and differential genotype proportions in the polymerase/surface and X/preCore regions. The genotype dynamics in HBV infection and the different patterns of quasispecies complexity in the HBV genome suggest a new paradigm for HBV genotype classification.     

Mutations and CpG islands among hepatitis B virus genotypes in Europe

Background

Hepatitis B virus (HBV) genotypes have a distinct geographical distribution and influence disease progression and treatment outcomes. The purpose of this study was to investigate the distribution of HBV genotypes in Europe, the impact of mutation of different genotypes on HBV gene abnormalities, the features of CpG islands in each genotype and their potential role in epigenetic regulation.

Results

Of 383 HBV isolates from European patients, HBV genotypes A-G were identified, with the most frequent being genotype D (51.96%) in 12 countries, followed by A (39.16%) in 7 countries, and then E (3.66%), G (2.87%), B (1.57%), F (0.52%) and C (0.26%). A higher rate of mutant isolates were identified in those with genotype D (46.7%) followed by G (45.5%), and mutations were associated with structural and functional abnormalities of HBV genes. Conventional CpG island I was observed in genotypes A, B, C, D and E. Conventional islands II and III were detected in all A-G genotypes. A novel CpG island IV was found in genotypes A, D and E, and island V was only observed in genotype F. The A-G genotypes lacked the novel CpG island VI. “Split” CpG island I in genotypes D and E and “split” island II in genotypes A, D, E, F and G were observed. Two mutant isolates from genotype D and one from E were found to lack both CpG islands I and III.

Conclusions

HBV genotypes A-G were identified in European patients. Structural and functional abnormalities of HBV genes were caused by mutations leading to the association of genotypes D and G with increased severity of liver disease. The distribution, length and genetic traits of CpG islands were different between genotypes and their biological and clinical significances warrant further study, which will help us better understand the potential role of CpG islands in epigenetic regulation of the HBV genome.     

Characterization of Acute and Chronic Hepatitis B Virus Genotypes in Canada

Objective

The prevalence and distribution of hepatitis B virus (HBV) genotypes in Canada is not known. Genotypic analysis may contribute to a better understanding of HBV strain distribution and transmission risk.

Methods

HBV surface antigen (HBsAg) positive samples of acute (n = 152) and chronic (n = 1533) HBV submitted for strain analysis or reference genotype testing between 2006 and 2012 were analyzed. The HBsAg coding region was amplified to determine the HBV genotype by INNO-LiPA assay or sequence analysis. Single and multivariate analyses were used to describe genotypes’ associations with known demographic and behavioral risk factors for 126 linked cases of acute HBV.

Results

Nine genotypes were detected (A to I), including mixed infections. Genotype C (HBV/C) dominated within chronic infections while HBV/D and A prevailed among acute HBV cases. History of incarceration and residing with a chronic HBV carrier or injection drug user were the most frequently reported risks for acute HBV infection. Over time, HBV/A increased among both acute and chronic infections, and HBV/C and HBV/D decreased among chronic infections.

Conclusion

Chronic and acute HBV genotypes in Canada differ in the relative distribution and their associations with known risk factors, suggesting different routes of transmission and clinical progression of infection.     

Comparison and significance of specific and non-specific cellular immunity in patients with chronic hepatitis B caused by infection with genotypes B or C of hepatitis B virus

The present study was designed to investigate possible relationships between the genotypes of hepa-titis B virus (HBV) and the HBV-specific cytotoxic T lymphocyte (CTL) responses. HBV genotypes, HBV specific CTL HBV DNA and other markers of HBV infection were determined in 138 patients with chronic hepatitis B. The results showed that the patients infected with genotype C (n=62) had a significantly lower HBV-specific CTL response than those who were infected with HBV genotype B (P<0.01). HBV DNA titer was higher in patients infected with HBV genotype C than in those infected with HBV geno-type B (P<0.01). Both alanine aminotransferase (ALT) and total bilirubin (TBIL) were higher in HBV genotype C infected patients than in those infected with genotype B (P<0.01 and <0.05, respectively). These results suggest that compared with CHB patients infected with HBV genotype B, the higher HBV DNA level and more severe liver damages in the patients infected with genotype C of HBV may be as-sociated with genotype C of the virus.     

Occult hepatitis B virus infection among injecting drug users in the Central-West Region of Brazil

The prevalence of occult hepatitis B virus (HBV) infection was investigated in 149 hepatitis B surface antigen (HBsAg) negative injecting drug users (IDUs) in the Central-West Region of Brazil. Of these individuals, 19 were positive for HBV DNA, resulting in an occult HBV infection prevalence of 12.7% (19/149); six of these 19 individuals had anti-HBV core and/or anti-HBV surface antibodies and 13 were negative for HBV markers. All IDUs with occult hepatitis B reported sexual and/or parenteral risk behaviours. All HBV DNA-positive samples were successfully genotyped. Genotype D was the most common (17/19), followed by genotype A (2/19). These findings reveal a high prevalence of occult HBV infection and the predominance of genotype D among IDUs in Brazil''s Central-West Region.     

Molecular Epidemiology and Genotyping of Hepatitis B Virus of HBsAg-Positive Patients in Oman

Background

Hepatitis B virus (HBV) infection is a major global health burden with distinct geographic public health significance. Oman is a country with intermediate HBV carrier prevalence; however, little is known about the incidence of HBV variants in circulation. We investigated the HBV genotype distribution, the occurrence of antiviral resistance, and HBV surface antigen (HBsAg) escape mutations in HBsAg-positive patients in Oman.

Methods

Serum samples were collected from 179 chronically HBV-infected patients enrolled in various gastroenterology clinics in Oman. HBV genotypes were determined by sequencing and phylogenetic analysis. Mutations in the HBV polymerase and the HBsAg gene were characterized by mutational analysis.

Results

HBV genotypes D (130/170; 76.47%) and A (32/170; 18.28%) are predominant in Oman. The HBV genotypes C and E were less frequent (each 1.18%), while the HBV genotypes B, G, F, and H were not detected. Four patients revealed HBV genotype mixtures (HBV-A/D and D/C). The analyses of vaccine escape mutations yield that 148/170 (87.06%) HBV sequences were wild type. 22/170 (12.94%) HBV sequences showed mutations in the “a” determinant of the HBsAg domain. Two patients showed the described HBV vaccine escape mutation sP120T. 8/146 (5.48%) HBV isolates harbored mutations in the HBV polymerase known to confer resistance against antiviral therapy. Especially the lamivudine resistance mutations rtL180M/rtM204V and rtM204I were detected.

Conclusion

This study shows the distribution of HBV genotypes, therapy resistance, and vaccine escape mutations in HBV-infected patients in Oman. Our findings will have a major impact on therapy management and diagnostics of chronic HBV infections in Oman to control HBV infection in this intermediate HBV-endemic country.