• Humans
• High-Throughput Nucleotide Sequencing/methods
• Hepatitis B virus/genetics
• Hepatitis B virus/drug effects
• Hepatitis B, Chronic/virology
• Hepatitis B, Chronic/drug therapy
• Genotype
• Genotyping Techniques/methods
• Drug Resistance, Viral/genetics
• Antiviral Agents/pharmacology
• Microbial Sensitivity Tests/methods
• Automation, Laboratory/methods
• DNA, Viral/genetics

• Hepatitis B virus
• Hepatitis B surface antigen
• Mutational analysis
• Vaccine escape

• C-gene
• Complete genome
• Hepatitis B virus
• Phylogenetic analysis
• Recombinants
• S-gene

The hepatitis B virus (HBV), belonging to the Hepadnaviridae family, is responsible for a global health concern still in the 21st century. The virus is divided into 10 genotypes, which differ in geographical distribution and in their effect on disease progression and transmission, susceptibility to mutations, and response to treatment. There are many methods for diagnostics of HBV and differentiating its genotypes. Various commercial kits based on real-time polymerase chain reaction (RT PCR) and hybridization available, as well as whole genome sequencing or the sequencing of only individual parts of the genomes. We compared a commercial kit AmpliSens HBV-genotype-FRT, based on RT PCR, with an adapted method of amplification of the surface genomic region combined with Sanger sequencing. In the examined samples we identified the A, B, C, D, and E genotypes. By PCR with Sanger sequencing, the genotypes were determined in all 103 samples, while by using the commercial kit we successfully genotyped only 95 samples, including combined genotypes, which we could not detect by sequencing.

• HBV genotype
• genotyping methods
• hepatitis B virus
• sequencing

• HBV
• HBsAg
• Mutation
• Quasispecies
• RT domain

• DNA G-quadruplex
• ELISA
• HBV surface antigen
• cccDNA
• hepatitis B virus
• microscale thermophoresis
• pre-core promoter
• small-angle X-ray scattering

• DNA, Circular/chemistry
• DNA, Circular/genetics
• G-Quadruplexes
• Hep G2 Cells
• Hepatitis B virus/genetics
• Humans
• Mutation
• Promoter Regions, Genetic/genetics

• Antiviral Agents/therapeutic use
• Genome, Viral/genetics
• Genotype
• Genotyping Techniques/methods
• Hepatitis B virus/genetics
• Hepatitis B, Chronic/drug therapy
• Hepatitis B, Chronic/virology
• Humans
• Nucleotides/therapeutic use
• Phylogeny
• Polymerase Chain Reaction
• Polymorphism, Restriction Fragment Length
• Whole Genome Sequencing

• classification
• genotypes
• human respiratory syncytial virus

• Hepatitis B virus
• Mutation rate
• N-glycosylation
• Stop codon
• Vaccine

It is commonly noticed that chaotic and inefficient subgenotyping are universally used academically and clinically, a standardized HBV genotype/subgenotype classification criterion is urgently acquired. Sequence similarity, which was commonly used for the last three decades, should be upgraded by phylogenetic analysis in genotyping of recombinant-free HBV strains.

In this study, 4,429 HBV whole-genome sequences were employed to reconstruct the phylogeny of HBV using Bayesian inference. After excluding recombinant sequences, calculating partitioned evolutionary models, excluding recombinant sequences, reconstructing phylogenetic trees, and performing a correlation analysis of genetic distances, geographical distribution and serotypes, we systematically redefined the genotypes and subgenotypes of HBV.

Compared to previous taxonomy, fourteen subgenotypes (A5-A7; B5-B9; C2-C4, C7; and D6-D7) were revised in the new standard. Now the HBV is divided into ten genotypes (A-J) and 24 subgenotypes (A1-A3; B1-B5; C1-C6; D1-D6; and F1-F4).

Our robust genotype/subgenotype new taxonomy has objectively re-molded the current shape of HBV classification. We believe that all future hepatitis B related researches or diagnosis will be benefited under the new HBV genotyping/subgenotyping standards.

• Clinical genetics
• Genotyping
• Hepatitis B virus
• Infectious disease
• Phylogenetic analysis
• Recombination
• Taxonomy

• Hepatitis B
• hepatitis B e-antigen (HBeAg)
• miRNA-146a
• prognosis
• serological conversion

Absolute quantification of HBV-DNA by sequence-encoded Quantitative Invader assay in a single tube without using calibration curves.

Genetic variation within hepatitis B surface antigen (HBsAg), in particular within the major hydrophobic region (MHR), is related to immune/vaccine and test failures and can have a significant impact on the vaccination and diagnosis of acute infection. This study shows, for the first time, variation among acute cases and compares the amino acid variation within the HBsAg between acute and chronic infections. We analyzed the virus isolated from 1231 acute and 585 chronic cases reported to an anonymized public health surveillance database between 2004 and 2014 in The Netherlands. HBsAg analysis revealed the circulation of 6 genotypes (Gt); GtA was the dominant genotype followed by GtD among both acute (68.2% and 17.4%, respectively) and chronic (34.9% and 34.2%, respectively) cases. Variation was the highest among chronic strains compared to that among acute strains. Both acute and chronic GtD showed the highest variation compared to that of other genotypes (P < .01). Substitutions within the MHR were found in 8.5% of the acute strains and 18.6% of the chronic strains. Specific MHR substitutions described to have an impact on vaccine/immune escape and/or HBsAg test failure were found among 4.1% of the acute strains and 7.0% of the chronic strains. In conclusion, we show a high variation of HBsAg among acute and chronic hepatitis B virus–infected cases in The Netherlands, in particular among those infected with GtD, and compare, for the first time, variation in frequencies between acute and chronic cases. Additional studies on the impact of these variations on vaccination and test failure need to be conducted, as well as whether HBsAg false–negative variants have been missed.

• amino acid variation
• hepatitis B surface antigen
• hepatitis B virus
• major hydrophobic region
• test failure
• vaccination

• HBsAg
• Hepatitis B Virus
• anti-HBs
• mutations

Proofreading deficiencies of hepatitis B virus polymerase result in frequent DNA mutations in the hepatitis B virus genome. Here, we performed sequencing analysis of the hepatitis B virus polymerase gene to assess its association with the postoperative survival in 92 patients with HBV-related hepatocellular carcinoma by using the Kaplan–Meier method. The 2525, 2733, 2738, 2768, 2946, 3063, 3066, 3109, 31, 529, 735, 939, 1078, 1137, 1383, 1461, 1485, 1544, and 1613 mutation sites were identified as being associated with HCC outcomes by the log-rank test. After adjusting for clinical characteristics by using the Cox hazard model, site 31 (relative risk, 8.929; 95% confidence interval, 3.433–23.22; P = 0.000) in the spacer domain and sites 529 (relative risk, 5.656; 95% confidence interval, 1.599–19.999; P = 0.007) and 1078 (relative risk, 3.442; 95% confidence interval, 1.070–11.068; P = 0.038) in the reverse transcriptase domain of hepatitis B virus polymerase were identified as independent predictors of postoperative survival in hepatitis B virus related hepatocellular carcinoma. The mutations at the 31 (Ser314Pro), 529 (Asp480Asn), and 1078 (Ser663Ala) sites all resulted in amino acid changes in hepatitis B virus polymerase and were associated with shortened life-span. The 31 and 529 sites were located in the overlapping region for the PreS and S genes but did not induce amino acid substitution in these two regions. Our finding of the correlation between hepatitis B virus DNA polymerase mutations and hepatocellular carcinoma survival will help identify the patients subgroup with poor prognosis, and help the clinicians to refine the therapeutic decision individualized.

• Carcinoma, Hepatocellular/complications
• Carcinoma, Hepatocellular/enzymology
• Carcinoma, Hepatocellular/pathology
• Carcinoma, Hepatocellular/surgery
• DNA-Directed DNA Polymerase/genetics
• Female
• Hepatitis B/complications
• Hepatitis B virus/enzymology
• Humans
• Liver Neoplasms/complications
• Liver Neoplasms/enzymology
• Liver Neoplasms/pathology
• Liver Neoplasms/surgery
• Male
• Middle Aged
• Mutation
• Postoperative Period
• Real-Time Polymerase Chain Reaction
• Survival Analysis

This study aimed to estimate the distribution of hepatitis B virus (HBV) C/D recombinant in Han and Tibet patients with chronic hepatitis B (CHB) and then learn such strain's replication capacity in vivo. A total of 331 serum samples were collected from Han outpatients from Sichuan Province and Tibetan outpatients from Tibet. Viral genotypes in these samples were identified. An HBV replicative plasmid of C/D recombinant was constructed with selected genome. Sequentially, HBV replicative mouse models were established and the replication capacity of the viral strain was studied in vivo. In the 314 Han patients, 66% (207) were infected by genotype B strain while 31% (96) were by genotype C strain. Only 1% (3) were by C/D recombinant. In the 17 Tibetan patients, 41% (7) were by genotype D and 35% (6) by C/D recombinant. A plasmid with 1.3 copies of C/D recombinant genome was constructed. And its replication intermediates were found at similar levels to that of genotype D strain. Thus, C/D recombinant, the dominant viral strain in Tibet, was rather rare in the genotype B predominated Han patients from Sichuan Province. And the C/D recombinant replicated at a similar level to viral strain of genotype D in vivo.

• Hepatitis B vaccine
• MSM
• chronic hepatitis B

Knowledge of hepatitis B virus (HBV) genotype is an important predictive variable which might have an impact in management and treatment of patients with chronic hepatitis B infection. In Ghana very little information is available on hepatitis B genotypes. This study was conducted to determine the distribution of HBV genotypes circulating among chronic hepatitis B patients reporting at the Korle-Bu Teaching Hospital (KBTH), Accra, Ghana.

Blood samples (10 ml) were collected from 250 consenting patients. DNA was extracted and amplified using polymerase chain reaction technique. Restriction fragment length polymorphism (RFLP) was used for the detection of genotypes.

Out of the 250 chronic hepatitis B patients who were HBsAg positive, 91 (36.4%) were males aged 29.8 ± 9.1 and 159 (63.6%) females aged 33± 12.1 years. HBV DNA was detected in 111 (44.4%) but only 58 (52%) of these were typeable. These were classified as genotype A, 8 (7.2%); genotype D, 3 (2.7%) and genotype E, 47 (42.3%). Our results did not show any association between the infecting genotype and age (X²= 0.923; p-value=0.623) or gender (X²= 0.283, p= 0.579).

Consistent with similar studies worldwide, the results suggest that genotypes A, D and E were the genotypes circulating among chronic hepatitis B patients who reported to the Korle-Bu Teaching Hospital with genotype E being the most predominant and therefore constitutes an important public health concern. We recommend further epidemiological studies to understand the implication of genotype E in terms of disease progression and treatment.

• Hepatitis B Virus
• chronic hepatitis B carriers
• hepatitis B genotype

A fast and low-cost method for HBV genotyping especially for genotypes A, B, C and D was developed and tested. A classifier was used to detect and analyze a one-step immunoassay lateral flow strip functionalized with genotype-specific monoclonal antibodies (mAbs) on multiple capture lines in the form of pattern recognition for point-of-care (POC) diagnostics. The fluorescent signals from the capture lines and the background of the strip were collected via multiple optical channels in parallel. A digital HBV genotyping model, whose inputs are the fluorescent signals and outputs are a group of genotype-specific digital binary codes (0/1), was developed based on the HBV genotyping strategy. Meanwhile, a companion decoding table was established to cover all possible pairing cases between the states of a group of genotype-specific digital binary codes and the HBV genotyping results. A logical analyzing module was constructed to process the detected signals in parallel without program control, and its outputs were used to drive a set of LED indicators, which determine the HBV genotype. Comparing to the nucleic acid analysis to HBV viruses, much faster HBV genotyping with significantly lower cost can be obtained with the developed method.

Although a successful vaccine against HBV has been implemented in 184 countries, eradication of hepatitis B virus (HBV) is still not on the horizon. There are over 240 million chronic carriers of HBV globally. The risk of developing chronic hepatitis ranges from >90% in newborns of hepatitis Be antigen (HBeAg)‐positive mothers, 25%–35% in children under 5 years of age and <5% in adults. HBeAg, a non‐particulate viral protein, is a marker of HBV replication. This is the only HBV antigen to cross the placenta, leading to specific unresponsiveness of helper T cells to the capsid protein and HBeAg in newborns. HBeAg is tolerated in utero and acts as a tolerogen after birth. Perinatal transmission is frequent when mothers are HBeAg‐positive, whereas it occurs less frequently when mothers are HBeAg‐negative. Sequence heterogeneity is a feature of HBV. Based on an intergroup divergence >7.5% across the complete genome, HBV is classified phylogenetically into at least nine genotypes. With between ~4% and 8% intergroup nucleotide divergence, genotypes A–D, F, H and I are classified further into subgenotypes. HBV genotypes/subgenotypes may have distinct geographical distribution and can develop different mutations in the regions of the HBV genome that code for HBeAg. These differences can be related to the role of HBV genotypes to the natural history of infection and mode of transmission. Thus genotypes/subgenotypes of HBV can be responsible for the different natural history of infection and modes of transmission in children, found in various regions of the world, where different genotypes/subgenotypes prevail. Copyright © 2016 John Wiley & Sons, Ltd.

• clinical
• diagnosis
• hepatitis B virus
• in vitro diagnostic assay
• infectious diseases
• multiplex
• nanotechnology
• patient samples
• quantum dot
• quantum dot barcodes
• sensitivity
• specificity

• Biological Assay/methods
• DNA, Viral/blood
• Fluorescent Dyes/chemistry
• Hepatitis B/diagnosis
• Hepatitis B virus/genetics
• Humans
• Limit of Detection
• Magnetite Nanoparticles/chemistry
• Microscopy, Fluorescence
• Microspheres
• Multiplex Polymerase Chain Reaction
• Quantum Dots/chemistry
• Sensitivity and Specificity
• Sequence Analysis, DNA
• Surface Properties

• MOP130143 CIHR
• COP126588 CIHR

• Akt
• HBx
• Hepatocellular carcinoma
• Phosphorylation

Hepatitis B virus (HBV) has a worldwide distribution and is endemic in many populations. Due to its unique life cycle which requires an error-prone reverse transcriptase for replication, it constantly evolves, resulting in tremendous genetic variation in the form of genotypes, sub-genotypes, and mutations. In recent years, there has been considerable research on the relationship between HBV genetic variation and HBV-related pathogenesis, which has profound implications in the natural history of HBV infection, viral detection, immune prevention, drug treatment and prognosis. In this review, we attempted to provide a brief account of the influence of HBV genotype on the pathogenesis of HBV infection and summarize our current knowledge on the effects of HBV mutations in different regions on HBV-associated pathogenesis, with an emphasis on mutations in the preS/S proteins in immune evasion, occult HBV infection and hepatocellular carcinoma (HCC), mutations in polymerase in relation to drug resistance, mutations in HBV core and e antigen in immune evasion, chronicalization of infection and hepatitis B-related acute-on-chronic liver failure, and finally mutations in HBV x proteins in HCC.

• Hepatitis B virus
• Genotype
• Variation
• Pathogenesis

• Antineoplastic Agents/adverse effects
• Genetic Variation
• Genome, Viral
• Genotype
• Hepatitis B/drug therapy
• Hepatitis B/etiology
• Hepatitis B/virology
• Hepatitis B virus/genetics
• Hepatitis B virus/pathogenicity
• Humans
• Immunosuppression Therapy/adverse effects
• Mutation
• Recurrence
• Viral Proteins/genetics
• Virulence/genetics

Major hydrophilic region in genomic HBV extending from aa99 to aa169, clustered with a highly conformational epitope, is critical to the antigenicity of hepatitis B surface antigen (HBsAg) and may affect the diagnosis of HBV in HBV screening test. So, this study aimed to characterize variants of S gene product of hepatitis B virus (HBV) isolated from patients with overt or occult HBV infection in north-eastern Egypt.

The study included sera of two different groups of volunteer blood donors (VBDs), 82 with overt HBV that were positive for HBsAg and anti-HBc and 343 donors negative for HBsAg eligible for donation. Of the latter group, only 44 were positive for anti-HBc. All anti-HBc positive sera were subjected to HBV DNA detection and partial sequence analysis targeting the HBV S gene.

HBV DNA was detected in 22.7 % of HBsAg-/anti-HBc + (10/44 patients) and in 90 % of HBsAg + donors (74/82 patients) with significant statistical difference (P = 0.0001). Phylogenetic analysis showed that HBV strains retrieved from both groups were of genotype D. Amino acid escape mutation T125M was detected in only 2 samples of the occult infection group and in none of the overt group (P = 0.01). Different amino acid substitutions were identified in overt infection group: S143L/T (16.2 %, 12/74) and P120T/S (2.7 %, 2/74). Q129R was significantly more frequent in cases with occult HBV infection (40 %, 4/10) than overt group (6.8 %, 5/74) (P = 0.01).

HBV genotype D predominated both in patients with overt and occult HBV infection. Different profiles of amino acid substitutions in the major hydrophilic region were seen in these two groups in Egypt.

Hepatitis B virus (HBV) is a hepatotropic virus causing hepatitis, cirrhosis and hepatocellular carcinoma (HCC). The methylation status of the HBV DNA in its different forms can potentially provide insight into the pathogenesis of HBV-related liver diseases, including HCC, however this is unclear. The goal of this study is to obtain comprehensive DNA methylation profiles of the three putative CpG islands in the HBV DNA in infected livers, with respect to liver disease progression. The extent of methylation in these CpG islands was first assessed using bisulfite PCR sequencing with a small set of tissue samples, followed by analysis using both quantitative bisulfite-specific PCR and quantitative methylation-specific PCR assays in a larger sample size (n = 116). The level of HBV CpG island 3 methylation significantly correlated with hepatocarcinogenesis. We also obtained, for the first time, evidence of rare, non-CpG methylation in CpG island 2 of the HBV genome in infected liver. Comparing methylation of the HBV genome to three known HCC-associated host genes, APC, GSTP1, and RASSF1A, we did not identify a significant correlation between these two groups.

Research has shown that hepatitis B virus (HBV) genotypes are closely linked to the clinical manifestations, treatment, and prognosis of the disease.

To study the association between genotype and drug-resistant HBV mutations in 620 Chinese patients with chronic HBV infection.

HBV DNA levels were determined using real-time quantitative PCR in plasma samples. Microarrays were performed for the simultaneous detection of HBV genotypes (HBV/B, C, and D) and drug-resistance-related hotspot mutations. A portion of the samples analyzed using microarrays was selected randomly and the data were confirmed using direct DNA sequencing.

Most samples were genotype C (471/620; 76.0%), followed by genotype B (149/620; 24.0%). Among the 620 patient samples, 17 (2.7%) had nucleotide analogs (NA) resistance-related mutations. Of these, nine and eight patients carried lamivudine (LAM)-/telbivudine (LdT)-resistance mutations (rtL180M, rtM204I/V) and adefovir (ADV)-resistance mutations (rtA181T/V, rtN236T), respectively. No patients had both lamivudine (LAM)- and either adefovir (ADV) or entecavir (ETV) resistance mutations. Additionally, out of the 620 patient samples, 64.0% (397/620) were also detected with the precore stop-codon mutation (G1896A) by microarray assay.

The results of the current study revealed that the prevalence of nucleotide analogs (NA)-resistance in Chinese hospitalized HBV-positive patients was so low that intensive nucleotide analogs (NA)-resistance testing before nucleotide analog (NA) treatment might not be required. In addition, the present study suggests that chronic HBV patients with genotype C were infected with fitter viruses and had an increased prevalence of nucleotide analogs (NA)-resistance mutations compared to genotype B virus.

• Chronic HBV
• Drug-resistance mutations
• Genotyping
• Microarray

• chronic HBV infection
• family screening
• northeast India
• viral genotype
• viral load

Reported acute hepatitis B incidence in the Netherlands reached its nadir in 2013. However, regional signals about increased number of hepatitis B cases raised the question how hepatitis B incidence was distributed over the country. In this study, regional differences in hepatitis B epidemiology were investigated using epidemiological and molecular data.

Acute hepatitis B virus (HBV) infections, reported between 2009–2013, were included. If serum was available, a fragment of S and C gene of the HBV was amplified and sequenced. Regional differences in incidence were studied by geographical mapping of cases and cluster analysis. Regional differences in transmission were studied by constructing regional maximum parsimony trees based on the C gene to assess genetic clustering of cases.

Between 2009 and 2013, 881 cases were notified, of which respectively 431 and 400 cases had serum available for S and C gene sequencing. Geographical mapping of notified cases revealed that incidences in rural border areas of the Netherlands were highest. Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions. Genetic cluster analysis showed that rural border areas had relatively large clusters of cases with indistinguishable sequences, while other regions showed more single introductions.

This study showed that regional differences in HBV epidemiology were present in the Netherlands. Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas. Therefore, preventive measures should be enhanced in these regions.

• Adult
• Female
• Hepatitis B/epidemiology
• Hepatitis B/transmission
• Hepatitis B virus
• Humans
• Incidence
• Male
• Middle Aged
• Molecular Epidemiology
• Molecular Sequence Data
• Netherlands/epidemiology
• Rural Population

• Amino Acid Sequence
• Codon/genetics
• Genome, Viral/genetics
• Genomics/methods
• Genotyping Techniques/methods
• Hepatitis E virus/genetics
• Phylogeny

The genotyping of the hepatitis C virus (HCV) plays an important role in the treatment of HCV because genotype determination has recently been incorporated into the treatment guidelines for HCV infections. Most current genotyping methods are unable to detect mixed genotypes from two or more HCV infections. We therefore developed a multiplex genotyping assay to determine HCV genotypes using a bead array. Synthetic plasmids, genotype panels and standards were used to verify the target-specific primer (TSP) design in the assay, and the results indicated that discrimination efforts using 10 TSPs in a single reaction were extremely successful. Thirty-five specimens were then tested to evaluate the assay performance, and the results were highly consistent with those of direct sequencing, supporting the reliability of the assay. Moreover, the results from samples with mixed HCV genotypes revealed that the method is capable of detecting two different genotypes within a sample. Furthermore, the specificity evaluation results suggested that the assay could correctly identify HCV in HCV/human immunodeficiency virus (HIV) co-infected patients. This genotyping platform enables the simultaneous detection and identification of more than one genotype in a same sample and is able to test 96 samples simultaneously. It could therefore provide a rapid, efficient and reliable method of determining HCV genotypes in the future.

• Hepatitis B Virus Receptor
• SCL10A1
• Sodium Taurocholate Cotransporting Polypeptide

• Classification
• Genotype
• Hepatitis
• Hepatitis B virus
• Phylogenetic tree
• Subgenotype

• Animals
• Antiviral Agents/therapeutic use
• Drug Resistance, Viral/genetics
• Emigration and Immigration
• Evolution, Molecular
• Genotype
• Hepatitis B/diagnosis
• Hepatitis B/drug therapy
• Hepatitis B/epidemiology
• Hepatitis B/transmission
• Hepatitis B/virology
• Hepatitis B virus/classification
• Hepatitis B virus/drug effects
• Hepatitis B virus/genetics
• Hepatitis B virus/pathogenicity
• Host-Pathogen Interactions/genetics
• Humans
• Phenotype
• Phylogeny

A number of nucleoside analogues such as lamivudine (LAM), actually used for the treatment of chronic hepatitis B, can suppress HBV DNA replication, improve transaminase level and liver histology, and enhance the rate of hepatitis B e antigen (HBeAg) clearance. The responses to LAM therapy involve HBeAg clearance and HBV DNA conversion of negative. However, the associations between HBV genotype B/C and response to LAM therapy remain ambiguous. The aim of this meta-analysis is to determine more precise estimations of the relationship. All the publications on the associations between HBV genotype B/C and response to LAM (HBeAg clearance and HBV DNA conversion of negative) through June 2013 were collected. Relative risk (RR) with 95% confidence intervals (95% CI) was calculated in fixed or random model, I² was calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects with Stata 11 software. Overall, for HBeAg clearance and genotype B/C, the RR (95% CI) was 1.27 (0.94–1.71), while for HBV DNA conversion of negative and genotype B/C, the RR (95% CI) was 1.07 (0.98–1.17). HBV genotype B/C shows no significance associations with response to lamivudine therapy (HBeAg clearance and HBV DNA conversion of negative).

• Direct Sequencing
• Genotype
• Hepatitis B Virus
• Restriction Fragment Length Polymorphism

• Genotype I
• HBV genotypes
• Hepatitis B virus
• India
• Viral recombination

In HBV-infected patients, different genotypes of the hepatitis B virus influence liver disease progression and response to antiviral therapy. Moreover, long-term antiviral therapy will eventually select for drug-resistant mutants. Detection of mutations associated to antiviral therapy and HBV genotyping are essential for monitoring treatment of chronic hepatitis B patients.

In this study, a simple method of partial-S gene sequencing using a common PCR amplification was established for genotyping clinical HBV isolates sensitively, which could detect the drug-resistant mutations successfully at the same time.

The partial S gene sequencing assay developed in this study has potential for application in HBV genotyping and drug resistant mutation detection. It is simpler and more convenient than traditional S gene sequencing, but has nearly the same sensitivity and specificity when compared to S gene sequencing.

The main transmission route of the hepatitis B virus (HBV) is mother to child transmission and contributes significantly to chronic HBV infection. Even though immunoprophylaxis with hepatitis B immunoglobulin (HBIG) and hepatitis B vaccine is administrated to neonates whose mothers are hepatitis B surface antigen (HBsAg) positive, about 10% of the neonates suffer from HBV infection in their early life.

To survey chronic HBV infection among pregnant women and their infants and analyze the reason for immunoprophylaxis failure.

Serum HBsAg was tested in all pregnant women. HBVDNA and other serum HBV markers including hepatitis B e antigen (HBeAg), hepatitis B core antibody (anti-HBc) and hepatitis B surface antibody (anti-HBs) were tested among HBsAg positive pregnant women. All infants whose mothers were HBsAg positive were vaccinated with a standard immunoprophylaxis. Serum HBV markers and HBVDNA were tested among these infants at 7 months of age. HBV genotypes were analyzed among the infants and pregnant women who were HBVDNA positive.

The prevalence of HBsAg, anti-HBc and anti-HBs among 4,536 pregnant women was 5.49%, 29.65% and 58.55%, respectively. The prevalence of HBsAg, anti-HBc and anti-HBs among pregnant women older than 20 years of age was significantly different compared to pregnant women younger than 20 years of age (4.54, 5.69 and 0.61 times, prevalence older vs. younger, respectively. P<0.05, 0.01, 0.05, respectively). Among 249 HBsAg positive pregnant women, 167 (67.07%) were HBeAg positive, 204 (81.93%) were HBVDNA positive and only 37 (14.86%) had HBVDNA >10⁷ IU/ml. Among the infants whose mothers were HBsAg positive, 214 (85.94%) infants were anti-HBs positive. There were 12 (4.82%) infants who were HBsAg and HBVDNA positive, and all 12 of these infants mothers were HBeAg positive and had HBVDNA >10⁷ IU/ml. Genotypes B and C were present among 165 pregnant women and genotype C was present in 85 pregnant women. There were 12 infants who were HBsAg positive and had the same HBV genotypes as their mothers. There was a significant difference in genotypes between the pregnant women whose infants were infected with HBV compared to those without HBV infection (P < 0.05).

There was a significant decline in HBsAg prevalence among pregnant women and their infants in Shenyang. Genotype C might be a risk factor for mother to child transmission of HBV.