Serologic and molecular characteristics of hepatitis B virus among school children in East Java, Indonesia

Genotypes, subtypes, and genetic variability of hepatitis B virus from blood donors in Timor-Leste

Timor-Leste experiences high hepatitis B endemicity; however, information about hepatitis B virus (HBV) variants in Timor-Leste is still limited. In this study, we determined genotypes and subtypes and identified mutations in the surface (S), polymerase (P), basal core promoter (BCP), precore (PC), and core (C) genes of HBV isolates from blood donors in Timor-Leste. Sera were examined using serological tests and PCR sequencing. Out of 127 sera tested, 38 (30%) were positive for the hepatitis B S antigen (HBsAg). Thirty-eight sequences of the S and P genes, 22 sequences of the BCP and PC regions, and 23 sequences of C genes were determined and analyzed. The most common genotype/subtype was C/adrq+, followed by B/ayw1, B/adw2, and C/adw2. Several mutations in the S protein that are associated with vaccine escape were identified in samples of genotype C (I110L, S113T, T126I, T143S, Y161F) and B (K122R), some of which might have been from vaccinated individuals. None of the healthy carriers had taken anti-HBV drugs, but one was infected with a virus with a mutation in the P gene associated with anti-HBV drug resistance (Y141F). The mutations A1762T and G1764A in BCP were detected in 18.1-22.7% of the samples. In the PC region, the mutation C1858T was the most frequent, followed by G1896A and G1899A. In the C gene, 13 mutations (P5T, T67N, E77Q, P79Q/A, E83D, V91T, I97L/F, L116I, and P130I/P/T) associated with severe liver disease were identified. Viruses obtained from four healthy carriers who were later found to have died of hepatocellular carcinoma also showed those mutations. In conclusion, among blood donors in Timor-Leste, HBV genotype/subtype C/adrq+ and several mutations in the S and C genes were prevalent. Routine implementation of a national immunization program and monitoring of disease progression in healthy carriers should be considered.

Hepatitis B virus infection after immunization: How serious it is? An updated review

Infection with hepatitis B virus (HBV) is one of the significant challenges worldwide. Despite the availability of antiviral drugs against this virus, the most critical strategy to prevent HBV infection is HB vaccination. Basically, despite widespread conventional HB vaccination, due to various reasons, including waning of hepatitis B surface antibody (HBsAb) titer after vaccination, the emergence of vaccine-escape mutants, failure to respond to the vaccine due to viral and host factors, levels of response in high-risk individuals and non-responders to conventional HB vaccination remains a major, unsolved and severe concern. This review focuses on the underlying reasons for conventional hepatitis B vaccination failures. It also suggests solutions to overcome these failures by highlighting significant advances in vaccination, including hepatitis B third-generation vaccines and adjuvanted hepatitis B vaccines as efficient alternatives to second-generation vaccines. Potentially, these new strategies will compensate for the shortcomings caused by second-generation vaccines. Adherence to these denouements has a significant role in preventing the circulation of HBV among individuals and reducing the global burden of HBV-related diseases.

Estimates of the global prevalence of occult hepatitis B virus infection in population under 18 years old: a systematic review and meta-analysis

OBJECTIVE

Occult hepatitis B virus infection (OBI) is defined by the presence of hepatitis B virus (HBV) DNA, while HBsAg (Hepatitis B surface antigen) remains undetectable. The infectivity of OBI and its potential ability to contribute to cirrhosis and hepatocellular carcinoma has been reported, with infection in children potentially leading to more severe outcomes. However, the global prevalence and disease burden remain unclear, and this study aimed to assess the prevalence of OBI in population under 18 years old.

METHODS

We conducted a systematic literature search in PubMed, Embase, Scopus, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Chinese databases for articles evaluating OBI in population under 18 years old. The prevalence of OBI was pooled after quality assessment.

RESULTS

A total of 49 studies was included, allowing a meta-analysis of 1,070,526 HBsAg-negative individuals. Data from 28 and 25 studies were extracted for analysis of the high- and low-risk population, respectively. The overall prevalence of OBI in population ≤ 18 years old was 2.1% [95% confidence interval (CI): 0.9%-3.8%] and 9.7% (95% CI: 4.9%-15.8%) in the low- and high-risk population, respectively. In the subgroup analysis of the high-risk population, the OBI prevalence in the African, Eastern Mediterranean, and Western Pacific regions was 21.5% (95% CI: 0.0%-69.9%), 26.8% (95% CI: 13.0%-43.4%), and 4.3% (95% CI: 1.5%-8.2%), respectively. The OBI prevalence was 6.3% (95% CI: 2.7%-11.1%) in children born to mothers infected with HBV, 20.5% (95% CI: 0.0%-66.6%) in population infected with HIV or HCV, and 37.8% (95% CI: 30.8%-45.1%) in population who received blood transfusion. The OBI prevalence was 6.0% (95% CI: 2.4%-11.0%) in participants whose mothers were infected with HBV and vaccinated with hepatitis B vaccine (HepB) and HBIG, 7.1% (95% CI: 0.0%-22.9%) in participants only vaccinated with HepB.

CONCLUSION

The global prevalence of OBI among individuals under 18 years old, particularly in high-risk population, cannot be neglected. Given the stealthy transmission of OBI and its potential for serious clinical outcomes, OBI in population younger than 18 years old should be emphasized as a global health issue.

Understanding the influence of cytokines in intrauterine hepatitis B transmission: A cross-sectional study in China

Cytokines may related to intrauterine Hepatitis B virus (HBV) transmission. 205 HBsAg(+) pregnant cases and 74 HBsAg(-) women were included. Neonatal blood samples were taken within 24 h of delivery and before HBV vaccinations. Serological HBV biomarkers and cytokines were detected. 21.9 % of the newborns from HBsAg(+) women were intrauterinally transmitted, including 7.3 % with dominant transmission (DBT) and 14.6 % occult transmission (OBT). HBV DNA load (odd ratio [OR], 1.44; 95 % confidence interval [CI], 1.05-1.98), interferon-γ (IFN-γ) (OR, 1.01; 95 %CI, 1.00-1.02) and toll-like receptor 9 (TLR9) (OR, 1.27; 95 %CI, 1.06-1.52) positively correlated with DBT. Only IFN-γ (OR, 1.01; 95 %CI, 1.00-1.01) positively associated with OBT. According to the generated restricted cubic spline, TLR9 was positively correlates with rise of DBT in a log-shape. It may be possible to develop a nomogram which intercalates these factors to predict intrauterine HBV transmissions. Further research should consider immune processes involved in chorioamnionitis.

Global prevalence of occult HBV infection in children and adolescents: A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Occult HBV infection (OBI) is a specific form of hepatitis B virus (HBV) infection and has the possibility of developing into hepatocellular carcinoma (HCC) in adults. This study aimed to estimate the global prevalence of occult HBV infection in children and adolescents.

MATERIALS AND METHODS

We systematically searched PubMed, Embase, Web of Science, and Cochrane databases for relevant studies on the prevalence of OBI in children and adolescents. Meta-analysis was performed using STATA 16 software.

RESULTS

Fifty studies were included. The overall prevalence of OBI in children and adolescents was 7.5% (95% CI: 0.050-0.103). In different risk populations, OBI prevalence was remarkably high in the HIV-infected population (24.2%, 95% CI: 0.000-0.788). The OBI prevalence was 0.8% (95% CI:0.000-0.029) in the healthy population, 3.8% (95% CI:0.012-0.074) in the general population, and 6.4% (95% CI: 0.021-0.124) in children born to HBsAg-positive mothers. Based on different serological profiles, the prevalence of OBI in HBsAg-negative and anti-HBc-positive patients was 6.6% (95% CI: 0.016-0.136), 3.0% (95% CI: 0.009-0.059) in HBsAg-negative and anti-HBc-negative patients, 4.6% (95% CI: 0.015-0.088) in HBsAg-negative and anti-HBs-positive patients, and 3.7% (95% CI: 0.001-0.102) in HBsAg-negative and anti-HBs-negative patients.

CONCLUSIONS

Despite HBV vaccination and hepatitis B immunoglobulin (HBIG), OBI is common in children and adolescents in high-risk groups.

The First Assessments of Pediatric HBV Immunization Coverage in Mauritania and Persistence of Antibody Titers Post Infant Immunizations

Background: The Hepatitis B virus (HBV) vaccine is used worldwide as an efficient tool to prevent the occurrence of chronic HBV infection and the subsequent liver disease. However, despite decades of vaccination campaigns, millions of new infections are still reported every year. Here, we aimed to assess the nationwide HBV vaccination coverage in Mauritania as well as the presence of protective levels of the antibodies against HBV surface antigen (HBsAb) following vaccination in a sample of children immunized as infants. Methods: To evaluate the frequency of fully vaccinated and seroprotected children in Mauritania, a prospective serological study was conducted in the capital. First, we evaluated the pediatric HBV vaccine coverage in Mauritania between 2015 and 2020. Then, we examined the level of antibodies against HBV surface antigen (HBsAb) in 185 fully vaccinated children (aged 9 months to 12 years) by ELISA using the VIDAS hepatitis panel for Minividas (Biomerieux). These vaccinated children were sampled in 2014 or 2021. Results: In Mauritania, between 2016 and 2019, more than 85% of children received the complete HBV vaccine regimen. While 93% of immunized children between 0 and 23 months displayed HBsAb titer >10 IU/L, the frequency of children with similar titers decreased to 63, 58 and 29% in children aged between 24–47, 48–59 and 60–144 months, respectively. Conclusions: A marked reduction in the frequency of HBsAb titer was observed with time, indicating that HBsAb titer usefulness as marker of protection is short lived and prompting the need for more accurate biomarkers predictive of long-term protection.

Overt and occult hepatitis B infection after neonatal vaccination: mother-to-infant transmission and HBV vaccine effectiveness

OBJECTIVES

Overt and occult hepatitis B infection (HBI) among mothers and infants were investigated, and the effectiveness of vaccination against HBI was evaluated based on transmission types.

METHODS

A hospital-based cohort was built with 2,734 mothers and 330 mother-infant pairs. Their demographic data were collected. Serological HBV markers, nested-PCR for HBV genes, viral load detection, and phylogenetic analysis were done.

RESULTS

The overall prevalence of HBI among mothers was 12.1% (330/2,734), with 10.4% for the overt type and 1.8% for the occult type. In 330 out of 1,650 (20%) mother-infant pairs, the overall, type-I (from overt mother to overt infant), type-II (from overt mother to occult infant), and type-Ⅲ (from occult mother to occult infant) transmissions were 1.9% (1/54), 5.6% (3/54) and 0.0% (0/7). The refinement of HBI classification improved the estimate of vaccine effectiveness against HBI from 74.4%-80.9% to 94.4%, which was more prominent for type-II. One mother-infant pair with type-II transmission shared nearly identical complete sequences. However, the high rate of lost-to-follow-up could not be ignored.

CONCLUSIONS

During the transition period, HBV is mainly transmitted from the overt type of HBI mother to infant. Intensive prenatal screening for mothers is vital.

High prevalence of occult hepatitis B infection (OBI) among healthy children and their parents in Alborz province, Iran; Vertical OBI, myth or truth?

BACKGROUND

Occult hepatitis B infection (OBI) has been described in various clinical settings including after hepatitis B virus (HBV) immunization. The purpose of study was to characterize the prevalence of OBI among immunized children from a subset of general population and the parents of OBI-positive cases.

METHODS

Sera of 1200 children from general population who have been previously immunized by HBV vaccine were assayed for anti-HBs. 660 were randomly selected for HBV DNA testing by different polymerase chain reaction (PCR) methods and were analysed by direct sequencing on surface genes.

RESULTS

None of participants were positive for HBsAg and anti-HBc. 549 (45.7%) and 651 (54.3%) cases had anti-HBs > 10 mIU/mL (responders) and < 10 mIU/mL (nonresponders) respectively. Of 660 selected specimens, 91 (16%) of children were positive for OBI. 23 (25.2%) and 68 (74.8%) of HBV DNA positive cases were belonged to responders and nonresponders, respectively, showing significant difference (P < .001). The mean levels of anti-HBs in OBI-positive and OBI-negative groups, showed no considerable variations. The mean viral load for OBI-positive cases showed substantial differences between responders and nonresponders (P = .007). Of 49 parents (98 individuals) of OBI-positive children 11 (22%) and 18 (36%) were positive for anti-HBc and anti-HBs respectively. Molecular testing was positive in 32 subjects (16 couples, 32.6%). In total, 6 mothers and 11 fathers were positive for OBI.

CONCLUSION

A proportion of OBI-positive vaccinated children could be existed in different populations. This finding could be arisen from vertical HBV transmission or vertical OBI possibly from their parents.

Serological profile of hepatitis B in children after the introduction of its vaccination in Burkina Faso

Viral hepatitis B is a public health issue. We establish the children serological profile of hepatitis B in Bobo-Dioulasso, six years after the introduction of hepatitis B vaccine into the Expanded Program on Immunization. This was a descriptive study of prospective data collection carried out in the Department of Pediatrics and the laboratory of virology of the Centre MURAZ of Bobo-Dioulasso between March 2013 and May 2013. Blood samples were made in search of the following hepatitis B serological markers: anti-HBcAb total, HBsAg, Ac anti-HBs, HBeAg, AcHBs, IgM anti-HBc total. The ELISA method with the Monolisa BIORAD reagents was used. A total of 2015 children were included, 1026 (50, 9%) boys and 989 (49.1%) girls, at an average age of 58±48 months. Out of these 2015 children, 53 (2.6%) were positive to HBsAg including 19 vaccinated cases, one child has received 3 doses plus 1 booster dose of hepatitis B vaccine. We found no statistically significant difference in the carriage of serologic markers of hepatitis B between the unvaccinated group and the vaccinated group. Large-scale studies should be carried out in Burkina Faso to see the real impact of vaccination on the health of our populations.

Deep sequencing of hepatitis B surface antigen gene in the preserved umbilical cords in immunoprophylaxis failure against mother-to-child HBV transmission

BACKGROUND

Vaccine escape mutants (VEMs) are one of the causes of breakthrough infections in the mother-to-child transmission of hepatitis B virus (HBV). We hypothesized that VEMs existing as minor populations in the maternal blood are associated with breakthrough infections in children. We sought to determine whether VEMs exist as minor populations in the preserved umbilical cords of children with breakthrough infections.

CASE PRESENTATION

Two families (Family 1: three children, Family 2: two children) were enrolled. Despite immunoprophylaxis, a breakthrough infection occurred in two Family 1 children and two Family 2 children. Preserved umbilical cords, serum, and nails were used for the HBV DNA analysis. To detect VEMs, we performed direct and deep sequencing of hepatitis B surface antigen gene. The direct sequencing showed that there were no VEMs in the serum of the children or mother of Family 1 and family 2, but it identified a G145A mutant in the nails of the mother of Family 2. In Family 1, deep sequencing detected a T143S mutant as a minor population (1.7-2.0%) in the umbilical cords and serum of all three children and in the serum of the mother. A T126A mutant was also detected in the umbilical cord (9.2%) and serum (7.0%) of the first-born child of Family 1. In Family 2, the deep sequencing showed no VEMs in the umbilical cords, but it detected D144A (2.5%) and G145A (11.2%) mutants in the serum of the 2nd-born child.

CONCLUSIONS

VEMs were present as minor populations in the preserved umbilical cords of children with breakthrough infections. The VEMs did not become major populations after the breakthrough infections. The evolution of VEMs from a minor form to a major form might not be a prerequisite for breakthrough infections in mother-to-child transmission.

Hepatitis B virus (HBV) infection amongst children in Senegal: current prevalence and seroprotection level

Introduction

Hepatitis B virus (HBV) infection is highly endemic in Senegal. HBV vaccine of all children has been introduced in 1999 and included in the Expanded Programme on Immunization in 2004. The aim of this study was to assess the HBV prevalence and immunity status against HBV amongst children in Senegal.

Methods

Between March and August 2016, consecutive children aged from 6 months to 16 years old were recruited in outpatient department of three main children hospitals in Senegal. Serum samples were analyzed for HBV serology (HBsAg, HBcAb, HBsAb) using ARCHITECT analyzer. Children with HBsAb levels ≥ 10 IU/l) were considered as seroprotected against HBV.

Results

During the study period, 295 children fulfilled the criteria for the study and were further analyzed. Three children were HBsAg positive giving a seroprevalence at 1.1% (95% CI: 0.2-3.3), 12/267 (4.5%, 95% CI=2.3-7.7) had positive HBcAb and 226/295 (76.6%, 71.4-81.3) had positive HBsAb including 191 (77.3%, 71.6-82.4) with isolated HBsAb related to previous active immunization. However only 165 children (56%, CI 50-62) had seroprotective HBsAb levels (HBsAb ≥ 10 UI/L) and 63 (21.4, 16.8-26) had a strong seroprotectiondefined by HBsAb ≥ 100 IU/L.

Conclusion

Our results suggest that although HBV prevalence has significantly decreased in children in Senegal following a better HBV vaccine coverage, the number of children correctly seroprotected is insufficient (56%). Assessing the levels of HBsAb and providing HBV vaccine boosters should be considered in children in Senegal.

Efficacy of Hepatitis B Vaccination among Children in Special Region of Yogyakarta, Indonesia: Evaluation of Humoral and Cellular Immunity

Hepatitis B remains a global burden, with estimated 15 to 40 percents of infected individuals eventually suffer from liver cirrhosis, liver failure, and hepatocellular carcinoma. Vaccination aims to form anti-HBs antibody with protective titer to prevent infection. CD4 T cell lymphocytes are known to play a major role in establishing immunity after vaccination. This study aimed to investigate protective titer rate among Indonesian children in Special Region of Yogyakarta following hepatitis B vaccination and correlation between anti-HBs titer and CD4 count. This is a cross-sectional study with 52 subjects between 8 months to 5 years of age in Bungas Community Health Service, Special Region of Yogyakarta, Indonesia. Anti-HBs titer was examined using enzyme immunoassay and CD4 count was examined using immunocytochemistry method. Of 52 subjects, median anti-HBs titer was 72.965 IU/L (interquartile range 360.98), mean CD4 count was 49.73% ± 29.75. Protective level of antibody was found in 73.1% of subjects. Correlation test was conducted and no correlation was found between anti-HBs titer and CD4 count (r=-0.104, p=0.464). Age was found to have a weak negative correlation with anti-HBs titer (r=-0.367, p=0.007). We found high rate of protective titer among children in Special Region of Yogyakarta who have completed hepatitis B vaccination series. No correlation was established between anti-HBs titer and CD4 count.

Profile of Mutations in the Reverse Transcriptase and Overlapping Surface Genes of Hepatitis B Virus (HBV) in Treatment-Naïve Indonesian HBV Carriers

Mutations in the reverse transcriptase (RT) region of the hepatitis B virus (HBV) genome are an important factor in low therapeutic effectiveness. Nonetheless, the prevalence of these mutations in HBV strains isolated previously in Indonesia has not been systematically examined. Therefore, in this study, we investigated the profile of mutations in the RT region and the associations of these mutations with amino acid changes in the surface protein in the virus of treatment-naïve Indonesian HBV carriers. Overall, 96 sequences of the full-length Indonesian HBV genomes (genotype B, n = 54; genotype C, n = 42) were retrieved from the National Center for Biotechnology Information. Naturally occurring primary and/or compensatory drug resistance mutations were found in 6/54 (11.1%) genotype B strains and in 1/42 (2.4%) genotype C strains. The potential mutations underlying resistance to a nucleos(t)ide analog and/or pretreatment mutations were more frequent in both genotypes but more frequent in genotype C strains than in genotype B strains. The A-B interdomain region in the RT gene was more frequently mutated in genotype C than in genotype B (3.51 ± 2.53 vs. 1.08 ± 1.52, P ＜ 0.001). Knowledge about the mutational profiles of the RT gene and changes in the surface protein may help clinicians to select the most appropriate antiviral drug and vaccination or HBV immunoglobulin regimen for management of HBV infection in Indonesia.

Current hepatitis B virus infection situation in Indonesia and its genetic diversity

Indonesia has a moderate to high endemicity of hepatitis B virus (HBV) infection. The risk for chronic HBV infection is highest among those infected during infancy. Since 1997, hepatitis B (HepB) vaccination of newborns has been fully integrated into the National Immunization Program. Although HBV infection has been reduced by the universal newborn HepB immunization program, it continues to occur in Indonesia. The low birth dose coverage and the presence of vaccine escape mutants might contribute to this endemicity among children. Although limited information is available for an analysis of occult HBV infection (OBI), several variations and substitutions in the pre-S/S region have been detected in Indonesian HBV strains. Additionally, persistent infection and disease progression of chronic hepatitis B are related to not only viral factors but also the host genome. Indonesia is one of the most ethnically heterogeneous nations, with Javanese and Sundanese as the two highest ethnic groups. This multi-ethnicity makes genomic research in Indonesia difficult. In this article, we focused on and reviewed the following aspects: the current hepatitis B immunization program and its efficacy, OBI, HBV infection among high-risk patients, such as hemodialysis patients, and research regarding the host genome in Indonesia.

Hepatitis B Virus Infection in Indonesia 15 Years After Adoption of a Universal Infant Vaccination Program: Possible Impacts of Low Birth Dose Coverage and a Vaccine-Escape Mutant

A universal hepatitis B vaccination program for infants was adopted in Indonesia in 1997. Before its implementation, the prevalence of hepatitis B surface antigen (HBsAg)-positive individuals in the general population was approximately 5-10%. The study aimed to investigate the hepatitis B virus (HBV) serological status and molecular profile among children, 15 years after adoption of a universal infant vaccination program in Indonesia. According to the Local Health Office data in five areas, the percentages of children receiving three doses of hepatitis B vaccine are high (73.9-94.1%), whereas the birth dose coverage is less than 50%. Among 967 children in those areas, the seropositive rate of HBsAg in preschool- and school-aged children ranged from 2.1% to 4.2% and 0% to 5.9%, respectively. Of the 61 HBV DNA-positive samples, the predominant genotype/subtype was B/adw2 Subtype adw3 was identified in genotype C for the first time in this population. Six samples (11.5%) had an amino acid substitution within the a determinant of the S gene region, and one sample had T140I that was suggested as a vaccine-escape mutant type. The low birth dose coverage and the presence of a vaccine-escape mutant might contribute to the endemicity of HBV infection among children in Indonesia.

Clearance of HBV DNA in immunized children born to HBsAg-positive mothers, years after being diagnosed with occult HBV infection

In a previous study, we observed immunoprophylaxis failure due to occult hepatitis B virus (HBV) infection (OBI) despite the presence of adequate levels of anti-HBs in 21 (28%) of 75 children born to HBsAg-positive mothers. The aim of the study was to explore the maintenance of this cryptic condition in this population. Of 21 OBI-positive children, 17 were enrolled. HBV serological profiles were determined by enzyme-linked immunosorbent assay. Highly sensitive real-time and standard PCR followed by direct sequencing were applied in positive cases. The mean age (±SD) of studied patients was 6.57 ± 2.75 years. All children still were negative for HBsAg. All but one (94%) were negative for HBV DNA. Only two children were positive for anti-HBc. The results of the most recent anti-HBs titration showed that 4 (23.5%) and 13 (76.5%) had low (<10 IU/mL) and adequate (>10 IU/mL) levels of anti-HBs, respectively. The only still OBI-positive patient had an HBV DNA level of 50 copy/mL, carried the G145R mutation when tested in 2009 and again in 2013 in the 'a' determinant region of the surface protein. Further follow-up showed that after 18 months, he was negative for HBV DNA. In high-risk children, the initial HBV DNA positivity early in the life (vertical infection) does not necessarily indicate a prolonged persistence of HBV DNA (occult infection). Adequate levels of anti-HBs after vaccine and hepatitis B immune globulin immunoprophylaxis following birth could eventually clear the virus as time goes by. Periodic monitoring of these children at certain time intervals is highly recommended.

Hepatitis B virus infection in Indonesia

Approximately 240 million people are chronically infected with hepatitis B virus (HBV), 75% of whom reside in Asia. Approximately 600000 of infected patients die each year due to HBV-related diseases or hepatocellular carcinoma (HCC). The endemicity of hepatitis surface antigen in Indonesia is intermediate to high with a geographical difference. The risk of HBV infection is high in hemodialysis (HD) patients, men having sex with men, and health care workers. Occult HBV infection has been detected in various groups such as blood donors, HD patients, and HIV-infected individuals and children. The most common HBV subgenotype in Indonesia is B3 followed by C1. Various novel subgenotypes of HBV have been identified throughout Indonesia, with the novel HBV subgenotypes C6-C16 and D6 being successfully isolated. Although a number of HBV subgenotypes have been discovered in Indonesia, genotype-related pathogenicity has not yet been elucidated in detail. Therefore, genotype-related differences in the prognosis of liver disease and their effects on treatments need to be determined. A previous study conducted in Indonesia revealed that hepatic steatosis was associated with disease progression. Pre-S2 mutations and mutations at C1638T and T1753V in HBV/B3 have been associated with advanced liver diseases including HCC. However, drug resistance to lamivudine, which is prominent in Indonesia, remains obscure. Although the number of studies on HBV in Indonesia has been increasing, adequate databases on HBV infection are limited. We herein provided an overview of the epidemiology and clinical characteristics of HBV infection in Indonesia.

Ultradeep Sequencing for Detection of Quasispecies Variants in the Major Hydrophilic Region of Hepatitis B Virus in Indonesian Patients

Quasispecies of hepatitis B virus (HBV) with variations in the major hydrophilic region (MHR) of the HBV surface antigen (HBsAg) can evolve during infection, allowing HBV to evade neutralizing antibodies. These escape variants may contribute to chronic infections. In this study, we looked for MHR variants in HBV quasispecies using ultradeep sequencing and evaluated the relationship between these variants and clinical manifestations in infected patients. We enrolled 30 Indonesian patients with hepatitis B infection (11 with chronic hepatitis and 19 with advanced liver disease). The most common subgenotype/subtype of HBV was B3/adw (97%). The HBsAg titer was lower in patients with advanced liver disease than that in patients with chronic hepatitis. The MHR variants were grouped based on the percentage of the viral population affected: major, ≥20% of the total population; intermediate, 5% to <20%; and minor, 1% to <5%. The rates of MHR variation that were present in the major and intermediate viral population were significantly greater in patients with advanced liver disease than those in chronic patients. The most frequent MHR variants related to immune evasion in the major and intermediate populations were P120Q/T, T123A, P127T, Q129H/R, M133L/T, and G145R. The major population of MHR variants causing impaired of HBsAg secretion (e.g., G119R, Q129R, T140I, and G145R) was detected only in advanced liver disease patients. This is the first study to use ultradeep sequencing for the detection of MHR variants of HBV quasispecies in Indonesian patients. We found that a greater number of MHR variations was related to disease severity and reduced likelihood of HBsAg titer.

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.

Hepatitis B virus infection in children

For two decades, hepatitis B vaccine has been integrated into national routine childhood vaccination programs in almost all countries. The prevalence of HBsAg has decreased in children worldwide. However, there are children who miss the benefit of hepatitis B vaccine in some regions and countries. Long-term follow-up studies have revealed the clinical outcomes of chronic hepatitis B virus infection in children. A small percentage of chronically infected children develop liver cirrhosis and hepatocellular carcinoma. However, it is controversial who should be treated and when antiviral treatment should be initiated in children. Compared with adult studies, the data are insufficient to evaluate the pathogenesis of hepatitis B infection and the efficacy of antiviral treatment in childhood. New antiviral drugs have been approved for children and adults. Also, oral antiviral drugs are administered to pregnant women to reduce the hepatitis B virus mother-to-child transmission rate.

Seroepidemiology and occult hepatitis B virus infection in young adults in Banjarmasin, Indonesia

Hepatitis B virus (HBV) infection remains a public health problem in Indonesia. There has been limited data regarding HBV infection in young adult population. This study aimed to evaluate the seroepidemiology of HBV infection and characterize occult HBV variants in healthy young adults in Banjarmasin, Indonesia, who were born before the implementation of the universal infant hepatitis B vaccination. Serum samples of 195 healthy young adults were tested for HBsAg, anti-HBc, and anti-HBs. The prevalence of HBsAg, anti-HBc, and anti-HBs was 9 (4.6%), 62 (31.8%), and 96 (49.2%), respectively. Seventy four (37.9%) samples were seronegative for all three parameters, indicating the susceptibility to HBV infection. Among 66 samples positive for HBsAg and/or anti-HBc, 13 (19.7%) were HBV DNA positive; of these, four were HBsAg positive and nine were HBsAg negative, and categorized as occult HBV infection. Most occult HBV cases had high-level anti-HBs (>100 IU/l), suggesting that blood with positive anti-HBs and anti-HBc could not be regarded as noninfectious. Thirteen amino acid substitutions were identified: T126S, P127S, Q129R, T131N, M133T, and Y161S in the HBsAg-positive group; P120T, T126I, G145S, Y161F, E164V, and V168F in the occult-HBV group; and T143S in both groups. More studies are required to provide data on the prevalence and characteristics of mutants to ensure reliable diagnosis. The occult HBV infection, combined with the HBsAg prevalence, could indicate the high HBV carriage among young adults in this area. The high percentage of individuals susceptible to HBV infection reiterates the need for catch-up immunization strategies targeted at young adults.

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.

Low prevalence of hepatitis B and C virus markers among children and adolescents

This study aimed to determine the prevalence of HBV and HCV among children and adolescents attending schools and daycare centres in Rio de Janeiro State, located in southern Brazil. Serum samples from 1,217 individuals aged 0 to 18 years were collected from 1999 to 2012 and tested for HBsAg, total anti-HBc, anti-HBs, and anti-HCV by ELISA. Reactive HBsAg and anti-HBc samples were tested for HBV DNA. Reactive anti-HCV samples were tested for HCV RNA and genotyped by RFLP. HBsAg was detected in 1.8% of individuals, and total anti-HBc was detected among 3.6% of individuals. Anti-HBs reactivity was found among 25.3% (322/1,217) of the individuals and increased from 6.28% in the years 1999-2000 to 76.2% in the years 2001–2012 (P < 0.0001). HBV DNA was detected in 18 of 51 individuals who presented with HBsAg or isolated anti-HBc, and nine were considered occult hepatitis B cases. Three individuals were anti-HCV- and HCV RNA-positive: two of them were infected with genotype 1, and the other was infected with genotype 3. Low levels of HBV and HCV markers were observed in children and adolescents. HBV immunity increased during the period of study, indicating that childhood universal HBV vaccination has been effective for controlling HBV infection in Brazil.

Molecular epidemiology of hepatitis B virus in Asia

Although safe and effective vaccines against hepatitis B virus (HBV) have been available for three decades, HBV infection remains the leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) worldwide, especially in Asian countries. HBV has been classified into at least 9 genotypes according to the molecular evolutionary analysis of the genomic DNA sequence and shown to have a distinct geographical distribution. Novel HBV genotypes/subgenotypes have been reported, especially from Southeast Asian countries. The clinical characteristics and therapeutic effectiveness of interferon (IFN) and nucleos(t)ide analogues vary among different HBV genotypes. Mutations at T1653C in subgenotype C2 from Japan and South Korea, C/A1753T and C1858T in subgenotype C1 from Vietnam, and C1638T and T1753V in subgenotype B3 from Indonesia were reported to be associated with advanced liver diseases including HCC. Genotype distribution in Japan has been changed by an increasing ratio of subgenotype A2 in chronic hepatitis B. While a large number of epidemiological and clinical studies have been reported from Asian countries, most of the studies were conducted in developed countries such as Taiwan, China, South Korea and Japan. In this review, the most recent publications on the geographical distribution of genetic variants of HBV and related issues such as disease progression and therapy in Asia are updated and summarized.

Hepatitis B and C virus infection among hemodialysis patients in Yogyakarta, Indonesia: Prevalence and molecular evidence for nosocomial transmission

Hemodialysis patients are at an increased risk of acquiring hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. However, the prevalence of hepatitis viral infection and its genotype distribution among hemodialysis patients in Indonesia are unclear. In order to investigate these issues and the possibility of nosocomial transmission, 161 hemodialysis patients and 35 staff members at one of the hemodialysis unit in Yogyakarta, Indonesia, were tested for serological and virological markers of both viruses. HBV surface antigen (HBsAg) was detected in 18 patients (11.2%) and in two staff members (5.7%). Anti-HCV was detected in 130 patients (80.7%) but not in any staff members. Occult HBV and HCV infection were detected in 21 (14.7%) and 4 (12.9%) patients, respectively. The overall prevalence rates of HBV and HCV infection among patients were 24.2% and 83.2%, respectively. HCV infection was independently associated with hemodialysis duration and the number of blood transfusions. Phylogenetic analysis revealed that 23 of 39 tested HBV strains (59%) were genotype B, 11 (28.2%) were genotype C, and 5 (12.8%) were genotype A. HCV genotype 1a was dominant (95%) among 100 tested HCV strains. Nosocomial transmission was suspected because the genotype distribution differed from that of the general population in Indonesia, and because the viral genomes of several strains were identical. These findings suggest that HBV and HCV infection is common among hemodialysis patients in Yogyakarta, and probably occurs through nosocomial infection. Implementation of strict infection-control programs is necessary in hemodialysis units in Indonesia.

Evaluation of adverse effects of mutein forms of recombinant human interferon alpha-2b in female swiss webster mice

Purpose. We successfully developed recombinant human interferon alpha-2b (rhIFN-α2b) and mutein forms through the site-directed mutagenesis technique. The mutein forms were developed by substituting cysteins at positions 2 and 99 with aspartic acids. The potential adverse effects of these rhIFN-α2bs were assessed by acute and subchronic studies. Methods. In the acute study, rhIFN-α2bs were subcutaneously administered to mice at a single dose of 97.5 μg/kg, 975 μg/kg, and 9.75 mg/kg BW and were observed for 14 days. In the subchronic study, single dose of 1.95 μg/kg and 19.5 μg/kg, respectively, was given subcutaneously every 3 days for 45 days. Results. No death as well as abnormality in body weight, behavior, presentation of main organs, and value of plasma SGPT and SGOT was observed. Wild type and mutein rhIFN-α2bs did not show significant adverse effects at dose up to 9.75 mg/kg BW. Administration of these rhIFN-α2bs given repeatedly did not induce any adverse effect. Conclusion. These results suggest that our rhIFN-α2bs are safe. However, further study is still needed to clarify the safety issue before use in clinical trial.

High prevalence of hepatitis B virus genotype C/C1 in the Minangkabau ethnic group in Indonesia

Background

The Minangkabau is one of the major ethnic groups in Indonesia. Previous studies with a limited number of samples have shown a different prevalence of HBV/C in the Minangkabau compared to the Indonesian population in general. The aim of this study was to assess the HBV genotype distribution pattern and the prevalence of pre-S, T1753V and A1762T/G1764A mutations among the Minangkabau HBV carriers. The samples were collected from Padang, West Sumatera and from western Java. Mixed primers for specific genotypes were used to determine the HBV genotype. Pre-S or S genes were amplified, sequenced and aligned with reference sequences from GenBank to derive a phylogenetic tree for subgenotyping. Pre-S genes were also analyzed for mutations. The basal core promoter (BCP) region was amplified and directly sequenced to analyze T1753V and A1762T/G1764A mutations.

Results

The predominant HBV genotype among the Minangkabau HBV carriers (n=117) was C (72.6%) followed by B (24.8%) and co-infection with B and C (2.6%). The prevalence of pre-S mutations, including both the pre-S deletion and pre-S2 start codon mutation, was 41.0%, and the T1753V and A1762T/G1764A mutations were found in 51.9% and 71.2% respectively. HBV/C1 was the predominant HBV subgenotype in the Minangkabau HBV carriers, and was found in 66.2%, followed by B3, B7, C8, B2, B9, C2, and C10 (18.3%, 7.0%, 2.8%, 1.4%, 1.4%, 1.4%, and 1.4% respectively). From samples that were found to be co-infected with HBV B and C, two samples were successfully cloned and subgenotyped, including one with mixed subgenotypes of B3 and C1, and another one with mixed subgenotypes of B7, C1, putative intergenotypic of B/A, and C/A. Furthermore, three samples from donors of non-Minangkabau ethnicity from Padang were found to be infected with an intragenotypic recombination form, including a putative recombinant of B8/B3 and B9/B7.

Conclusion

HBV/C with subgenotype C1 was the predominant HBV genotype among HBV carriers of Minangkabau ethnicity. The prevalence of pre-S, A1762T/G1764A, and T1753V mutations was higher among the Minangkabau compared to Indonesian HBV carriers in general.

[Research activities in Kobe-Indonesia Collaborative Research Centers]

Kobe-Indonesia Collaborative Research Center was established in Institute of Tropical Disease (ITD), Airlangga University, Surabaya, Indonesia in 2007 under the program of ''Founding Research Centers for Emerging and Reemerging Infectious Diseases'' supported by the Ministry of Education, Culture, Sports, Science and Technology, Japan, and then it has been under the Japan Initiative for Global Research Network on Infectious Diseases (J-GRID) since 2010. Japanese researchers have been stationed at ITD, conducting joint researches on influenza, viral hepatitis, dengue and infectious diarrhea. Also, another Japanese researcher has been stationed at Faculty of Medicine, University of Indonesia, Jakarta, carrying out joint researches on'' Identification of anti-hepatitis C virus (HCV) substances and development of HCV and dengue vaccines'' in collaboration with University of Indonesia and Airlangga University through the Science and Technology Research Partnership for Sustainable Development (SATREPS) supported by the Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA) since 2009. In this article, we briefly introduce the background history of Kobe University Research Center in Indonesia, and discuss the research themes and outcomes of J-GRID and SATREPS activities.

Gaps in the prevention of perinatal transmission of hepatitis B virus between recommendations and routine practices in a highly endemic region: a provincial population-based study in China

BACKGROUND

Hepatitis B virus (HBV) infection is endemic in China; perinatal transmission is the main source of chronic HBV infection. Simultaneous administration of hepatitis B immune globulin (HBIG) and hepatitis B vaccine is highly effective to prevent perinatal transmission of HBV; however, the effectiveness also depends on full adherence to the recommended protocols in daily practice. In the present investigation, we aimed to identify gaps in immunoprophylaxis of perinatal transmission of HBV between recommendations and routine practices in Jiangsu Province, China.

METHODS

Totally 626 children from 6 cities and 8 rural areas across Jiangsu Province, China, born from February 2003 to December 2004, were enrolled; 298 were born to mothers with positive hepatitis B surface antigen (HBsAg) and 328 were born to HBsAg-negative mothers. Immunoprophylactic measures against hepatitis B were retrospectively reviewed for about half of the children by checking medical records or vaccination cards and the vaccine status was validated for most of children.

RESULTS

Of 298 children born to HBV carrier mothers, 11 (3.7%) were HBsAg positive, while none of 328 children born to non-carrier mothers was HBsAg positive (P < 0.01). The rates of anti-HBs ≥ 10 mIU/ml in children of carrier and non-carrier mothers were 69.5% and 69.2% respectively (P = 0.95). The hepatitis B vaccine coverage in two groups was 100% and 99.4% respectively (P = 0.50), but 15.1% of HBV-exposed infants did not receive the timely birth dose. Prenatal HBsAg screening was performed only in 156 (52.3%) of the carrier mothers. Consequently, only 112 (37.6%) of HBV-exposed infants received HBIG after birth. Furthermore, of the 11 HBV-infected children, only one received both HBIG and hepatitis B vaccine timely, seven missed HBIG, two received delayed vaccination, and one missed HBIG and received delayed vaccination.

CONCLUSIONS

There are substantial gaps in the prevention of perinatal HBV infection between the recommendations and routine practices in China, which highlights the importance of full adherence to the recommendations to eliminate perinatal HBV infection in the endemic regions.

Mutations within enhancer II and BCP regions of hepatitis B virus in relation to advanced liver diseases in patients infected with subgenotype B3 in Indonesia

Studies on the characteristics of mutations within the hepatitis B virus (HBV) genome, their roles in the pathogenesis of advanced liver diseases, and the involvement of host properties of HBV-infected individuals have not been conducted in subgenotype B3-infected populations. For addressing this issue, 40 cases with HBV surface antigen (HBsAg)-positive advanced liver diseases, including advanced liver cancer and cirrhosis (male 31, female 9, age 54.4 ± 11.6-year-old), were collected and compared with 109 cases with chronic hepatitis B (male 71, female 38, age 38.0 ± 13.4-year-old). Mutations in enhancer II (Enh II) and basal core promoter (BCP)/precore regions were analyzed by PCR-direct sequencing method. HBV viral load was examined by real-time PCR. For all examined regions, the prevalence of mutation was significantly higher in cases with advanced liver diseases. Multivariate analysis showed that, in patients older than 45 years, C1638T and T1753V mutations constituted independent risk factors for the advancement of liver diseases. The presence of C1638T and T1753V mutations may serve as predictive markers for the progression of liver diseases in Indonesia and other countries, where subgenotype B3 infection is prevalent.

Distribution Characteristics of Hepatitis B Serological Markers in Hospitalized Children and Adolescents in Zhejiang, China between 2006 and 2010

Background/Aims

To investigate serological patterns of hepatitis B based on electrochemiluminescent immunoassays and the distribution characteristics of these patterns in hospitalized children and adolescents in Zhejiang, China between 2006 and 2010.

Methods

Five serological markers, including hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), antibody to hepatitis B surface antigen (anti-HBs), antibody to hepatitis B e antigen (anti-HBe), and antibody to hepatitis B c antigen (anti-HBc), were chosen as a routine panel to monitor hepatitis B virus (HBV) infection and vaccination efficacy. A total of 33,187 children (21,187 boys and 12,000 girls) were selected using the following exclusion criteria: a previous diagnosis of hepatitis, age >16 years or an address outside of Zhejiang.

Results

The average HBV vaccination coverage rates among 20,766 boys and 11,782 girls were 98.62% and 98.68%, respectively. Seventeen serological patterns of hepatitis B were found, and the dominant pattern was 'anti-HBs (+) alone' (62.03%) followed by 'negative pattern' (23.46%). The rates of the other 15 patterns ranged from 8.14% to 0.003%. Of 236 HBsAg-positive patients, the overall rate of seropositivity was 0.71%. The anti-HBs levels were grouped into 3 ranges (10-100 mIU/mL, 100-1,000 mIU/mL, and >1,000 mIU/mL) for all anti-HBs-positive children (36.08%, 43.43%, and 20.49%, respectively).

Conclusions

A low HBsAg carrier rate and a relatively high anti-HBs positive rate are present in hospitalized children and adolescents in Zhejiang. The distribution of serological patterns is associated with age but is mostly independent of gender.