Hepatitis B virus genotypes and spontaneous hepatitis B e antigen seroconversion in Taiwanese hepatitis B carriers

Hepatitis B virus (HBV) is classified into eight genotypes (A-H), and genotype C is associated with more aggressive liver disease compared to genotype B. However, the mechanisms responsible for the clinical differences remain unclear. To test whether genotype C patients had with lower rates of spontaneous hepatitis B ge antigen (HBeAg) seroconversion than genotype B patients, stored serum samples from 146 Taiwanese adult HBeAg-positive hepatitis B carriers followed-up for a mean of 52 months (range, 12-120 months) were tested for HBV genotype by a molecular method. Genotype C patients were significantly older than genotype B patients (mean age, 37 +/- 12 vs. 29 +/- 10 years, P < 0.001). During the follow-up period, genotype C patients had a significantly lower rate of spontaneous HBeAg seroconversion than genotype B patients (27 vs. 47%, P < 0.025). Spontaneous HBeAg seroconversion occurred one decade later in genotype C patients compared with genotype B patients. Multivariate analyses identified age < or =35 years (odds ratio: 2.08; 95% confidence interval [CI], 1.07-4.0; P < 0.05), high baseline serum alanine aminotransferase level (odds ratio: 2.34; 95%CI, 1.39-4.09; P < 0.005), and HBV genotype B (odds ratio: 1.94; 95%CI, 1.03-3.63; P < 0.05) as independent factors associated with spontaneous HBeAg seroconversion. In conclusion, genotype C patients, compared to genotype B patients, have a delayed HBeAg seroconversion in the immune clearance phase of chronic HBV infection, which may contribute to a more progressive liver disease and more refractory to antiviral therapy.     

Hepatitis B pre-S1 and pre-S2 proteins: clinical significance and relation to hepatitis B virus DNA

Pre-S proteins may have an important role in virus assembly and virus entry into the host cell. The presence of pre-S proteins in serum has also been thought to correlate with active viral replication. To investigate whether pre-S proteins in serum might have additional diagnostic and/or predictive value for liver sequelae in HBV infection, sera from six different serological groups of patients with HBV markers (total number 363) and different manifestations of liver histology were examined for the presence of pre-S1 and pre-S2 proteins using micro-ELISAs. Pre-S1 and pre-S2 proteins were detected significantly more often in HBV-DNA-positive than in HBV-DNA-negative sera from HBsAg carriers. However, pre-S1 and pre-S2 proteins were also found in HBV-DNA-negative HBsAg carriers irrespective of serum HBeAg/anti-HBe or liver histologic findings. These results suggest that the presence of the pre-S1 and or pre-S2 proteins in serum either does not seem to reflect the presence of active viral replication and active liver disease or pre-S proteins are more readily detectable than HBeAg and HB-DNA as measured by a dot-blot technique. Furthermore, the presence of pre-S proteins in serum is strongly correlated with that of HBsAg.     

Hepatitis B virus DNA in serum of healthy black African adults positive for hepatitis B surface antibody alone: possible association with recombination between genotypes A and D

In some patients with chronic liver disease induced by hepatitis B virus, viral DNA is known to persist in low concentration in serum after seroconversion to hepatitis B surface antibody-positivity. This phenomenon has, however, not been documented in asymptomatic black African carriers of hepatitis B virus. Using nested amplification by the polymerase chain reaction, we detected low concentrations of hepatitis B virus DNA in the serum of 6 of 23 (26%) healthy black African adults with normal liver function and with hepatitis B virus surface antibody as the only serological marker of the virus. This finding offers one explanation for the earlier observation of integrated hepatitis B virus DNA in hepatocellular carcinomas in black Africans whose serum was positive for surface antibody alone. A number of genetic changes were found in the six isolates that might be responsible for evasion of the immune response and persistence of the virus. Isolated mutations were detected in the "a" determinant of the surface gene and in the encapsidation signal. In all five isolates sequenced in the core promoter, mutations were present in the upstream regulatory region. Recombination between genotypes A and D was present in three of the isolates, including both of those in which the entire genome was sequenced. This change in genotype also overlapped the amino end of the polymerase domain and may result in sufficiently low levels of replication to allow viral persistence. Topoisomerase 1 specific trinucleotides were concentrated in the vicinity of the recombination breakpoints.     

Impact of universal vaccination on intrafamilial transmission of hepatitis B virus

To control hepatitis B virus (HBV) infection, a nationwide vaccination program was launched in 1984 and resulted in a significant reduction in the rate of persistent infection of children. However, the relative contribution of vaccination to the intrafamilial clustering of HBV infection remains unclear. The rate of intrafamilial HBV transmission in vaccinated children was investigated. Eighty-four sera from vaccinated children were enrolled and HBV serum markers were determined. The modes of intrafamilial HBV transmission were investigated by history taking and serological assay, and confirmed by genotyping and phylogenetic analysis. The results showed 66 (78.6%) vaccinated children born to hepatitis B surface antigen (HBsAg)-negative parents were HBsAg-negative. Eighteen vaccinees were born to HBsAg-positive parents; four (21.4%) of the children were HBsAg-positive. According to the parents' HBsAg status, three patterns of HBsAg-positive parents were identified. Serological analysis showed that three of 15 children born to HBsAg-positive mother (pattern I) and one of two children born to HBsAg-positive father became infected (pattern II). The remaining one child was HBsAg negative with both parents positive for HBsAg (pattern III). Genotyping and phyogenetic analysis confirmed the mode of intrafamilial transmissions. Sequence analysis of S and pre-S genes showed that HBV isolates of HBsAg-positive vaccinees were variants; no G145R but G145A and other substitutions were found. In conclusion, this small study showed that both maternal and paternal transmissions are important of the intrafamilial spread of HBV infection. In addition, the introduction of HBV vaccination has resulted in a reduction of intrafamilial transmission, but a study of a large population is needed.     

Molecular epidemiology of hepatitis B virus in Spain: identification of viral genotypes and prediction of antigenic subtypes by limited sequencing

The hepatitis B virus (HBV) genotypes were studied by a line probe assay (LiPA) and by direct sequencing of a 339 nucleotide fragment from the S region of the viral genome in samples from 269 carriers living in Spain, either native to Spain (231) or immigrants from Africa, Asia, and Eastern Europe (38). The sequences were also used to predict the HBV surface antigen (HBsAg) subtype on the basis of the amino acids specified at selected positions of the HBsAg molecule. Agreement between the two genotyping methods was found in most cases (98.1%) and a HBV genotype could be assigned to all samples. The viral groups D/ayw2 (30.1%), D/ayw3 (28.6%), and A/adw2 (21.2%) were prevalent, with an additional participation of the groups D/ayw4 (4.8%), F/adw4q- (1.9%), A/ayw1 (1.9%), and D/adw3 (0.7%), all of them present among the autochthonous carriers. Strains from genotypes B and C were found exclusively among Chinese immigrants. Genotype E strains were found in immigrants from Central Africa and in one patient native of Spain. Point mutations leading to amino acid changes of residues involved in the expression of the HBsAg subtype determinants were found in 12 samples (4.5%). Some mutations would predict the putative novel genotype-subtype associations A/adw4q+, A/ayr, D/ayr, and E/ayw1, while others would suggest the loss of subtype-specific determinants. The finding of HBV strains characteristic for Africa among the autochthonous carriers confirms the emergence of African HBV strains in Spain.     

Dengue virus serotypes and genotypic characterization from northeast India

Dengue is a rapidly spreading acute arboviral infection transmitted through a human and Aedes mosquito cycle. Though northeast region of India has been experiencing dengue outbreaks regularly for over a decade, reports on genetic characterization of the virus from this region are limited. The present study was undertaken to detect the genotype and genetic composition of circulating dengue virus (DENV) in this region. Blood samples were collected from 918 suspected dengue patients of five northeast Indian states. Serological investigations, viz, nonstructural 1 (NS1) enzyme-linked immunosorbent assay (ELISA), immunoglobulin M (IgM) ELISA, and immunoglobulin G (IgG) ELISA were performed followed by molecular detection. Sequence analysis and phylogenetic tree construction based on capsid-premembrane (C-prM) gene junction was done by BioEdit and MEGA6 software, respectively. Serological detection showed 35.34% NS1 and 18.12% IgM positivity. Secondary infection was observed in 24.53%. All four serotypes were detected. Phylogenetic analysis demonstrated circulation of genotype III of DENV-1, genotype IV of DENV-2, and genotype III of DENV-3. Sequences from this region form distinct clades in the phylogenetic tree. Characterization of the C-prM gene junction reveals divergence among the DENV strains. As genetic variation within the DENV is known to be associated with diverse clinical outcomes, information regarding the genetic composition of circulating virus could be beneficial in designing an effective intervention strategy.     

Prevalence and clinical significance of hepatitis D virus co-infection in patients with chronic hepatitis B in Korea

Hepatitis D virus (HDV) infection can cause severe acute and chronic liver disease in patients infected with hepatitis B virus (HBV). Despite the significant decline in the global HDV infection, it remains a major health concern in some countries. This study aimed to investigate the prevalence and clinical features of HDV co-infection in patients with chronic HBV infection in Korea, where HBV infection is endemic. Nine hundred forty patients [median age, 48 (18-94) years; men, 64.5%] infected chronically with HBV were enrolled consecutively. All patients who were positive for hepatitis B surface antigen (HBsAg) for at least 6 months and were tested for anti-HDV. A portion of the HDV delta antigen was amplified, sequenced, and subjected to molecular and phylogenetic analysis using sera from the patients who were anti-HDV positive. Clinical features and virologic markers were evaluated. Inactive HBsAg carriers, chronic hepatitis B, cirrhosis and hepatocellular carcinoma accounted for 29.5%, 44.7%, 17.9%, and 8.0%, respectively. Only three patients were positive for anti-HDV, corresponding to a 0.32% positive rate. All patients who were positive for anti-HDV were inactive HBsAg carriers. HDV RNA could be amplified by PCR from the sera of two patients. Phylogenetic analysis showed that both carried HDV genotype 1. In conclusion, the prevalence of HDV infection is very low (0.32%) in Korea. All HDVs were genotype 1 and detected in inactive HBsAg carriers. Therefore, HDV co-infection may not have a significant clinical impact in Korean patients with chronic HBV infection.     

Hepatitis B virus infection in upper and lower Egypt

The relative prevalence of hepatitis B surface antigen (HBsAg), anti-HBs, and anti-hepatitis B virus core antigen (HBc), as markers of hepatitis B virus infection, among 1,866 apparently healthy residents of two Egyptian provinces representing Upper and Lower Egypt populations was determined using solid-phase radioimmunoassay (SPRIA). The prevalence rate of HBsAg in the Egyptian population was moderately high (10.1%); it was higher in the Upper Egypt (11.7%) than the Lower Egypt (8.0%) population and more frequent in young adults--especially those of Upper Egypt--and males than females in both populations. The prevalence of anti-HBs gradually increased with age; it was higher in the Lower Egypt (51.1%) than the Upper Egypt (41.7%) population, and it was higher in females than males. A remarkably high infection rate, as shown by the prevalence of anti-HBc, was found in both populations (88.0%), with minor variations depending on age, sex, and geographic area.     

贵州乙型肝炎病毒基因型分布及意义分析

目的调查贵州乙型肝炎病毒（HBV）基因型分布。方法选择贵阳、遵义、凯里、都匀慢性HBV感染者693例，其中无症状携带者（ASC）292例，慢性肝炎（CH）276例，肝硬化（LC）76例，肝细胞肝癌（HCC）49例。用S基因限制性片段长度多态性确定基因型，比较主要基因型的地区分布及其与临床的关系。结果693例中，B基因449例（64．79％），C型233例（33．62％），A型6例（0．87％）。D型5例（0．72％），未发现E、F基因型。B型的分布：凯里最高（96．40％），遵义、都匀其次（78．79％、76．19％），贵阳最低（53．66％）。C型的分布，贵阳（45．68％）高于都匀（23．80％）、遵义（13．13％）及凯里（3．96％），差异有统计学意义（P≤0．01）。与B型相比，C型感染者平均年龄大；ALT水平高；HBeAg阳性率低（P≤0．01）。除ASC组外，B、C2种基因型在CH、LC和HCC中的分布差异有统计学意义（P均〈0．01）。结论贵州存在A、B、C、D4种HBV基因型，但以B型为主，C型其次，A型、D型仅占很小比例。B、C基因型在贵州不同地区的分布有一定差异。与B型相比，C型感染者肝脏损害的程度较重。     

The Putative Recombination of Hepatitis B Virus Genotype B with Pre-C/C Region of Genotype C

Among hepatitis B virus (HBV) genotypes the B and C are most prevalent in China. To further study on the inside story of the intertypes, the genotype of 136 sequences from Chinese patients were analyzed either by restriction fragment length polymorphism on fragments or by phylogenetic analysis and bootscanning on full genome. The 22 complete sequences of genotype B clustered with different genotypes depending on gene fragments analyzed, which indicated that recombinant events occurred during HBV evolutionary history. To locate the recombinant regions, the sequences of HBV entire genome were analyzed by SimPlot program. The recombinant regions of B genotype with recombination were mapped in the pre-C/C region with relatively less varied size. Besides, three sequences of genotype C have recombination with genotype B or D in different regions. However, among all of the 136 sequences, none of authentic genotype B was identified. To investigate the possible mechanism responsible for intertype recombination, the selection pressure on the recombinant region was estimated by using CODEML program. All models allow for positively selected sites suggest existence of positive selection pressure. In conclusion, the genotype B with recombination was exclusive subgroup of genotype B in China. The mosaic genotype B might result from immune pressure on the pre-C/C gene.     

Hepatitis B virus genotypes in Uzbekistan and validity of two different systems for genotyping

Hepatitis B virus (HBV) has been classified into seven genotypes, designated A-G. The HBV genotype has a characteristic geographical distribution. The Republic of Uzbekistan is located in the heart of Asia and has been considered to be a region with high endemicity of hepatitis viruses. However, the present distribution of hepatitis virus infection in this region is unknown. The aim of this study was to investigate the distribution of HBV genotypes and to elucidate the validity of two genotyping systems in Uzbekistan. Fifty-four patients with hepatitis B surface antigen were investigated. HBV genotypes were determined by two methods: one based on restriction fragment length polymorphism (RFLP) targeting to S region, and another on enzyme-linked immunosorbent assay (ELISA), using monoclonal antibodies to pre-S2 region. Seven (13%) and 47 (87%) of the 54 subjects were classified into genotypes A and D, respectively. Dual infection of two viral populations of the same genotype was observed in one subject. No significant difference of ALT level (203.3 +/- 244.7 vs. 190.6 +/- 39.5) and HBeAg (42.9% vs. 42.6%) were found between genotypes A and D. In this study, the validity of the genotyping systems in this region was confirmed.     

Prevalence of Hepatitis B and Hepatitis C Virus Co-infection in India: A Systematic Review and Meta-analysis

Hepatitis B virus (HBV) and hepatitis C virus (HCV) have several important similarities including worldwide distribution, hepato-tropism, similar modes of transmission and the ability to induce chronic infection that may lead to liver cirrhosis and hepatocellular carcinoma. Since both viruses are individually known to cause the pathologies mentioned above, co-infection with both HBV and HCV would be expected to be linked with higher morbidity as well as mortality and impact healthcare resource utilisation. Precise estimate of the prevalence of HBV/HCV co-infection would be needed to formulate policy decisions and plan communal health interventions. This systematic review and meta-analysis, therefore, aims to understand the prevalence of HBV and HCV co-infection in India based on the available literature. Following PRISMA guidelines, primary studies reporting the prevalence of HBV/HCV co-infection in India were retrieved through searches conducted in PubMed, Google SCHOLAR, Medline, Cochrane Library, WHO reports, Indian and International journals online. All online searches were conducted between December 2016 and February 2017. Meta-analysis was carried out using StatsDirect statistical software. Thirty studies published between 2000 and 2016 conducted across six regions of India were included in this review. The pooled HBV/HCV co-infection prevalence rate across the thirty studies was 1.89% (95% confidence intervals [CI] = 1.2%–2.4%). A high heterogeneity was observed between prevalence estimates. The HBV/HCV co-infection prevalence in different subgroups varied from 0.02% (95% CI = 0.0019%–0.090%) to 3.2% (95% CI = 1.3%–5.9%). The pooled prevalence of HBV/HCV co-infection in India was found to be 1.89%. This systematic review and meta-analysis revealed high prevalence of HBV/HCV co-infection in chronic liver patients, followed by HIV-positive patients, and then followed by persons who inject drugs and kidney disease patients.     

Change of hepatitis B virus genotypes in acute and chronic infections in Japan

During 35 years from 1971 to 2005, 153 patients with acute and 4,277 with chronic HBV infection visited the Toranomon Hospital in Tokyo, Japan. They were grouped into seven 5-year periods, and HBV genotypes/subgenotypes were determined. Patients with acute HBV infection were younger (P = 0.046), predominantly male (P = 0.004), possessed higher alanine aminotransferase levels (P < 0.001), positive more frequently for HBeAg (P < 0.001), and had lower HBV DNA loads (P = 0.014) than those with chronic infection. Sexual transmission was more frequent in patients with acute than chronic HBV infection (67% vs. 3%, P < 0.001). The number of patients with acute infection increased throughout 1971-2005. Patients with chronic infection increased since 1971, peaked in 1986-1990 and then decreased. The number of patients increased since 1990-2000 again, however, reflecting recent boost of acute HBV infection. The distribution of HBV genotypes was considerably different between patients with acute and chronic infections (A, B, and C: 28.6%, 10.3%, and 59.5% vs. 3.0%, 12.3%, and 84.5%, respectively, P < 0.001). Since 1991, genotype A foreign to Japan started to increase sharply in patients with acute infection, and gradually in those with chronic infection. There was a trend for the foreign subgenotype B2/Ba to increase recently (P < 0.05). Despite immunoprophylaxis of high-risk babies born to carrier mothers with hepatitis B e antigen, implemented nationally since 1986, acute and chronic infections with HBV have been increasing in Japan. Based on genotypes/subgenotypes changing with time, the resurgence of hepatitis B could be attributed to infections, with foreign HBV genotypes/subgenotypes, spreading swiftly by sexual contact.     

云南省乙型肝炎病毒基因型和血清型的流行状况分析

目的了解云南省人群中流行的乙型肝炎病毒（Hepatitis B virus,HBV）基因型和血清型分布情况。方法从参加健康体检的人群中筛查HBsAg阳性的血清标本,利用巢式PCR扩增HBVS基因片段,并对扩增产物进行序列测定,从GenBank中查获A～I基因型共27株HBV参考序列,构建HBVS基因系统发生树,以此确定其样本的基因型及血清型,并对结果进行统计分析。结果从2216名体检人员血清标本中筛查出39份HBsAg阳性的样本,HBV的s基因序列分型结果表明有4种基因型：c型占76．9％,B型占15．4％;D型占5．1％;I型占2．5％。血清分型结果为：adw2型占71．8％;adrq‘型占17．9％;ayr型占10．3％。所有adw2血清型标本均为c基因型。HBsAg、HBeAg双阳性标本中75％为c基因型／adw2血清亚型。结论云南省HBV感染人群中HBV基因型的分布以C型为主,血清型以adw2型为主。     

Hepatitis C virus is frequently coinfected with serum marker-negative hepatitis B virus: Probable replication promotion of the former by the latter as demonstrated by in vitro cotransfection

Patients with hepatitis C have been reported occasionally to be coinfected with serum marker-negative (silent) hepatitis B virus (HBV). The frequency and significance of such coinfection were investigated. Thirty patients with hepatitis C virus (HCV) infections (10 acute, 10 chronic, 10 cirrhotic) were selected randomly; the acute cases were without serum hepatitis B surface antigen (HBsAg) and anti-hepatitis B core IgM, and the chronic cases were without HBsAg. A nested polymerase chain reaction for the X open reading frame was used to amplify HBV DNA in serum, and immunoperoxidase staining was carried out on liver biopsy specimens. Nucleotide sequencing was carried out to characterize the amplified HBV DNAs. In order to clarify the possibility that the silent HBV mutant promotes HCV replication in the liver, the full-length HCV RNA and the cloned silent HBV DNA dimer were cotransfected into an established cell line, HuH-7, and the amount of secreted HCV RNA was quantified serially. The target HBV DNA was amplified in 26 (86.7%) of the 30 patients. Subsequent direct nucleotide sequencing in 9 selected patients revealed an 8-nucleotide deletion, characteristic of a silent HBV mutant. Immunostaining revealed hepatitis B surface antigen in 15 (50.0%). Cotransfected silent HBV DNA augmented the secretion of HCV RNA by up to 5-fold in comparison with HCV RNA transfection alone. In conclusion, HCV is coinfected frequently with the silent HBV mutant and the latter probably promotes the replication of the former in the liver. J. Med. Virol. 52:399–405, 1997. © 1997 Wiley-Liss, Inc.     

Hepatitis B virus in Gizan, Saudi Arabia

The enzyme-linked immunosorbent assay (ELISA) was used to study the prevalence rates for hepatitis B virus surface antigen (HBsAg), antibody to surface antigen (anti-HBs), and antibody to core antigen (anti-HBc) in 724 voluntary donors, students, pregnant women and those seeking treatment for minor ailments in the Gizan area of Saudi Arabia. Tests for hepatitis B e antigen (HBeAg) and e antibody (anti-HBe) were made in HBsAg positive sera. There was serological evidence of an existing or earlier infection in 337 Saudis (46.5%), of whom 12.7% were HBsAg carriers, 25.4% were positive for anti-HBs, and 8.4% were positive only for anti-HBc. The percentage of HBsAg carriers was 19.9% and 9.3% in males and females, respectively (p less than 0.001). The evidence of existing or earlier infection in males (58.7%) was significantly higher than in females (38.7%) (p less than 0.001), with no intersex difference in anti-HBs or anti-HBc. No difference was observed in the positivity of either of the markers, alone or together, between the cord blood and the female population in the child-bearing age of 20-39 years. Corresponding to the values in other age groups, there was an overall fall in the number of HBsAg carriers during adolescence as well as in 20-39-year-old females. Among the HBsAg carriers, there was no significant difference between the two sexes for HBeAg and anti-HBe positivity. The HBsAg carrier rate of 19.9% in males is consistent with the high male dominant prevalence of hepatocellular carcinoma in the Gizan area.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatitis C genotypes in patients with dual hepatitis B and C virus infection

In patients with chronic hepatitis B and C virus (HBV, HCV) infection, an inverse relationship in the replicative activity of the two viruses has been reported. In the present study the genotype of HCV was evaluated in 34 consecutive cases found with hepatitis B surface antigen (HBsAg) and anti-HCV in the serum, in order to identify its possible influence in determining the pattern of HBV/HCV interaction. Nineteen patients were HCV-RNA positive and could be genotyped: 8 were infected by HCV-1 (3 by HCV-1a and 5 by HCV-1b), 10 by HCV-2, and only 1 by HCV-3. Among these, 3 were HBV-DNA positive, compared to 10 of 15 HCV-RNA-negative patients (P = 0.003), and all 3 were coinfected with HCV-2. Mean alanine aminotransferase (ALT) levels were similar between patients infected with HCV-1 and HCV-2. Among 7 patients with cirrhosis 5 were infected by HCV-2, while 6 of 12 of those without cirrhosis had HCV-1 infection. In conclusion, HBV replication was inhibited more efficiently by HCV-1 than by HCV-2. Cirrhosis was frequently found in patients with dual HBV and HCV-2 infection. © 1996 Wiley-Liss, Inc.     

Hepatitis B and D virus infection among drug abusers in Taiwan

Approximately 15 to 20% of the general population in Taiwan are chronic hepatitis B surface antigen (HBsAg) carriers. However, the incidence of hepatitis D virus (HDV) infection is low (5-8%) in patients with HBsAg-positive chronic liver diseases in this area. To evaluate the prevalence of hepatitis B virus (HBV) and HDV infection among drug abusers in Taiwan, serum samples were collected from 152 drug abusers at the Taipei Municipal Anti-Narcotic Institute and test for HBV and HDV markers. Of these, 24 (15.8%) were HBsAg positive, and only 15 (9.9%) were seronegative for all HBV markers. Of the 115 intravenous drug abusers, serum antibody to hepatitis D antigen (anti-HD) was positive in 78.9% of 19 persons who were HBsAg positive, and in 7.5% of 80 persons who were positive for antibody to HBsAg (anti-HBs). Anti-HD was not detected in the sera from all 37 nonintravenous drug abusers regardless of the status of their HBV markers. Also, none of 63 asymptomatic HBsAg carrier pregnant women or 23 patients with acute type B viral hepatitis had measurable anti-HD in their sera. Thus, the high frequency of HDV detected among Chinese HBsAg carrier intravenous drug abusers in Taiwan is similar to that reported in Western countries.