Subgenotype A1 Research Articles

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

People living in settlement projects represent an emergent rural population in Brazil. Data on their health is scarce and there are no data on viral hepatitis in this population. This study investigated the epidemiology of viral hepatitis A-E in residents of settlement projects in central Brazil. During 2011 and 2012, 923 people living in rural settlements in central Brazil were interviewed and tested to estimate the prevalence of exposure to viral hepatitis A-E, to identify the circulating hepatitis B virus (HBV)/hepatitis C virus (HCV) genotypes and risk factors for HBV exposure and to evaluate adherence to the hepatitis B vaccination series. Overall, 85.9, 3.9, 0.4 and 17.3% of individuals showed evidence of exposure to hepatitis A virus (HAV), hepatitis E virus, HCV and HBV, respectively. Among HBV-DNA positive samples (n=8), subgenotypes A1 (n=3) and A2 (n=1) and genotype D/subgenotype D3 (n=4) were identified. Hepatitis D virus superinfection was detected in 0/16 HBsAg-positive participants. A total of 229 individuals showed serological evidence of HBV vaccination. In total, 442 settlers were eligible for vaccination, but only 150 individuals completed the vaccine series. All anti-HCV-positive samples (n=4) were also HCV-RNA positive and identified as subtype 1a. The intermediate endemicity of HAV, the higher prevalence of HBV exposure compared with urban areas and the low compliance with HBV vaccination requires preventive measures focused on rural populations, emphasizing the need for HAV and HBV vaccination.

Variety of the hepatitis B virus genovariants in the military

Aim. To estimate the distribution of genotypes and subgenotypes of the hepatitis B virus among military personnel with chronic viral hepatitis B. Materials and methods. The work used samples of blood plasma and biopsy material obtained from 90 active or retired military personnel with chronic viral hepatitis B with various degrees of fibrosis undergoing treatment in St. Petersburg. Primary detection of HBV was carried out by isolating nucleic acids (NK) from the blood plasma using the «AmplePrime Ribo-prep» commercial kit (FBIS CRIE, Moscow). Specific primers were used for the amplification and sequencing reaction. Overlapping primer pairs were used, jointly flanking 1475 base pairs (bp) fragment, including the recommended for HBV genotyping the 1169 bp Pre-S1/Pre-S2/S. Results. Among 90 samples from patients with chronic viral hepatitis B from different regions of the Russian Federation, HBV subgenotypes are represented in the following ratios: D2 = 45.6% (n=41), D1 = 32.2% (n=29), D3 = 13.3% (n=12), A2 = 6.7% (n=6), D4 and A1 by 1.1%, respectively. The distribution of HBV subgenotypes from the North Caucasian federal district (D1 – 63.6%, D2, D3, D4, A2 – by 9.1%) was significantly different from the distribution among patients from the Central and North-Western federal districts (D1-20, 9%, D2 – 58%, D3 – 16.3%, A2 – 4.8%) (χ2=11,9приp=0,0076, df=3). Uncharacteristic for the Russian Federation subgenotypes D4 and A1, representing single imported cases. The tendency to shift the distribution of genovariants due to imports of the corresponding HBV subgenotypes from other countries, including the Central Asian countries, is discussed. Conclusion. A systematic study of the HBV isolates phylogeny provides new information about the HBV subgenotypes distribution among certain population groups, including military personnel.

Characterization of a Novel Avian Avulavirus 1 of Class I isolated from a Mute Swan (Cygnus Olor) in Macedonia in 2012

Abstract Avian avulavirus type 1 (AAvV-1) belongs to the family Paramyxoviridae, genus Avulavirus. Even though belonging to a single serotype, there is great genetic variability between these viruses. On the basis of the available complete fusion (F) gene and whole genome sequences and using the genotype classification system, AAvV-1 viruses are divided in two major groups: class I and class II. Class I viruses are predominantly avirulent viruses and majority of the isolations come from waterfowl and domestic poultry from live bird markets in USA and China although isolations from wild birds are reported globally. In our study we used classical, molecular and phylogenetic tools to characterize an AAvV-1 isolated from a mute swan in Macedonia. Based on the complete F gene sequence, we have concluded that the virus designated as AAvV-1/mute swan/Macedonia/546/2012 (KP123431) belongs to the class I of AAvV-1 with an avirulent cleavage site motif 112ERQER*L117. The virus could not be assigned to any of the four currently existing subgenotypes (1a, 1b, 1c or 1d) of the single genotype 1 of class I viruses. Two distant viruses, isolated from goose in Alaska in 1991 and from goose in Ohio in 1987, shared the highest nucleotide sequence identity of the complete F gene with the isolate in our study: 92.7% and 92.8%, respectively. This is the first report of isolation of class I AAvV-1 in Southeastern Europe. The asymptomatic nature and the underreporting of sequences from the class I viruses impede the understanding of the molecular epidemiology and evolution of this group of viruses.

The Investigation of Drug Resistance Substitutions in NS3 Protease Sequence of Hepatitis C Virus from Non-Responder Patients.

Background:Even with the fantastic successes of direct-acting antivirals (DAA) in the treatment of Hepatitis C Virus (HCV) infection, natural drug resistance remains a challenging obstacle for their impacts. The data regarding protease inhibitors (PIs) resistance in Iran population are limited. The aim of this study was to investigate the variations in NS3 protease of HCV from non-responder patients.Methods:In this cross-sectional study, 14 HCV infected patients with genotype 1(N=5) and 3(N=9) who have not responded to Interferon-related regime were enrolled from Liver Clinic, Shiraz. The NS3 protease region was amplified by Nested-PCR followed by product gel extraction. Besides, some amplified protease regions were cloned into a cloning vector to improve the sensitivity of mutation detection. Both crude and cloned sequences were then introduced into sequencing. The obtained sequences were compared with the NS3 reference sequences and analyzed by Geno2pheno available software to find possible substitutions. In the end, the phylogenetic tree was constructed. Results:Among variations responsible for PIs resistance, only one out of 14 (7%) sample who was infected with genotype 1a, harbored R117C+N174S double mutation, which causes reduced susceptibility to Telaprevir. Any another resistance mutation was not found among the studied population. The most frequent substitutions were determined as I52M(N=9), S102A(N=9), S166A(8) and V170I(8) for genotype 3a, and F147S/A(4) for genotype 1. However, some uncharacterized substitutions on scored position, including I132L(N=1), I170V(N=3) and N174S(N=2) were also determined among sequences. Phylogenetic analysis demonstrated that the protease region has enough power to correctly classify enrolled samples into relevant clusters on the tree. There were 2, 3 and 9 cases of sub-genotypes 1a, 1b, and 3a, respectively.Conclusion:A low frequency of PIs resistance mutations in our HCV infected population is a hopeful point of starting these drugs in HCV infected patients.

Multiple genotypes of Echovirus 11 circulated in mainland China between 1994 and 2017

Echovirus 11 (E-11) is one of the most frequently isolated enteroviruses causing meningitis and other diseases such as hand, foot, and mouth disease (HFMD) and acute flaccid paralysis (AFP). Fifty-nine newly determined E-11 VP1 sequences from the China AFP and HFMD surveillance network and 500 E-11 VP1 sequences obtained from the GenBank database, which were associated with 12 categories of diseases, were screened for phylogenetic analysis. Based on the standard method of genotype classification, E-11 strains circulated worldwide were reclassified into six genotypes as A, B, C, D, E, and F, in which genotype F is newly divided, and genotypes A and C are further divided into A1–5 and C1–4 by this research, whereas genotype D was still divided into D1–5 as in a previous study of Oberste et al. Sub-genotype A1 was the predominant sub-genotype in mainland China between 2008–2017, whereas sub-genotype D5 was the predominant sub-genotype circulated outside China from 1998–2014. However, genotype and sub-genotype spectra showed statistical significance among AFP and HFMD cases (χ2 = 60.86, P < 0.001), suggesting that different genotypes might have a tendency to cause different diseases. Strengthening the surveillance of E-11 might provide further information about pathogenic evolution or specific nucleotide mutation associated with different clinical diseases.

Screening and Molecular Characterization of Hepatitis E Virus in Slaughter Pigs in Serbia.

Hepatitis E virus (HEV) is a zoonotic virus that can cause acute hepatitis in humans. Besides the fecal-oral route, transmission can occur by consumption of undercooked pig liver. Genotype 3 is the most frequent genotype found in Europe. Studies on HEV in slaughter-age pigs have not been conducted in Serbia so far. Pork meat production and consumption in Serbia is on average, higher than in the rest of Europe. With the aim to identify the circulating HEV genotypes, pig livers and swab samples from three pig slaughterhouses located in three different sub-regions of Serbia were collected. A nested RT-PCR was used to amplify the hypervariable HEV ORF-1 region (334bp). The amplicons yielded in this study were sequenced, and a molecular phylogeny analysis based on the maximum likelihood method, including HEV sequences reported in several other countries, was performed. The average prevalence of HEV genotype 3 in 3-month-old pigs was 34%. Phylogenetic analysis revealed the majority of HEV amplification fragments from Serbia were grouped in four clades within sub-genotype 3a and were also genetically related to German, Italian, Slovenian, and American HEV sequences. Sub-genotypes 3b and 3j were also found in a single pig each. This study provides the first analysis of the genetic diversity and circulation dynamics of HEV in pigs at slaughterhouses in Serbia.

Hepatitis B virus infection among oncohematologic disease patients in Central Brazil: prevalence, risk factors and immunization

IntroductionCarriers of oncohematological diseases are at high risk for hepatitis B virus (HBV) infection. Objective and methodTo investigate the epidemiology of HBV infection in Goiânia, Central Brazil, 322 individuals with oncohematological diseases (leukemias, Hodgkin lymphoma and non-Hodgkin lymphoma) were interviewed and blood samples were collected for the detection of serological markers of HBV-DNA by polymerase chain reaction (PCR). Medical records of participants were also reviewed. ResultsNon-Hodgkin’s lymphomas (n=99) and chronic myeloid leukemia (n=108) were the most frequent oncohematological diseases. The overall prevalence of HBV was 13.97% (45/322). Of the total participants, 8.69% (28/322) presented isolated positivity for anti-HBs, suggesting low vaccine coverage. HBV-DNA was detected in 25% (1/4) of HBsAg positive samples and in 25% (3/12) of anti-HBc isolated, suggesting HBV occult infection. All samples were identified as subgenotype A1. Entries in patient records and the findings of this investigation suggest anti-HBc seroconversion during oncologic treatment. Age 50 years or over and use of a central catheter during therapy were associated with HBV exposure. ConclusionThe low frequency of hepatitis B immunized individuals, detection of HBV DNA in HBsAg negative samples, and the suggestion of HBV exposure during treatment evidenced the potential for health-related viral dissemination in people with oncohematological diseases in our region, reinforcing the importance of serological monitoring, vaccination against hepatitis B, and adoption of strict infection control measures in these individuals.

Molecular epidemiology of hepatitis B virus in Paraguay

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

High Frequency of Either Altered Pre-Core StartCodon or Weakened Kozak Sequence in the CorePromoter Region in Hepatitis B Virus A1 Strainsfrom Rwanda.

Hepatitis B virus (HBV) is endemic in Rwanda and is a major etiologic agent for chronic liver disease in the country. In a previous analysis of HBV strains from Rwanda, the S genes of most strains segregated into one single clade of subgenotype, A1. More than half (55%) of the anti-HBe positive individuals were viremic. In this study, 23 complete HBV genomes and the core promoter region (CP) from 18 additional strains were sequenced. Phylogenetic analysis of complete genomes confirmed that most Rwandan strain formed a single unique clade, within subgenotype A1. Strains from 17 of 22 (77%) anti-HBe positive HBV carriers had either mutated the precore start codon (9 strains with either CUG, ACG, UUG, or AAG) or mutations in the Kozak sequence preceding the pre-core start codon (8 strains). These mutually exclusive mutations were also identified in subgenotypes A1 (70/266; 26%), A2 (12/255; 5%), and A3 (26/49; 53%) sequences from the GenBank. The results showed that previous, rarely described HBV variants, expressing little or no HBeAg, are selected in anti-HBe positive subgenotype Al carriers from Rwanda and that mutations reducing HBeAg synthesis might be unique for a particular HBV clade, not just for a specific genotype or subgenotype.

Viral Hepatitis B: Seroprevalence and Genetic Diversity in Blood Donors North of Congo

Introduction: Viral hepatitis B is the most formidable and confusing of all viral hepatitis, given its cirrhogenic and carcinogenic potential. The objective of the study is to characterize the molecular profile of hepatitis virus B in northern Congo. Materials and Methods: This was a descriptive and cross-sectional study that was carried out between January and September 2014, that is 9 months, in the establishments of the National Center for Blood Transfusion (CNTS) of the 4 departments of the north of the Congo. Epidemiological, serological and molecular variables (HBsAg, HBV DNA, genotypes and subtypes) were studied. The HBs antigen was searched by rapid test and confirmed by ELISA. For all positive donors, conventional and specific gene extraction and amplification techniques were performed for the identification of genotypes and subtypes from the serum. Results: A total of 892 donors were included. The average age was 35.36 ± 12.36 years with extremes ranging from 18 to 65 years old. The sex ratio (M/F) was 3.3. The prevalence of HBV was 8.6%. The viral DNA of HBV was amplified in 83.1%. Four genotypes were found: E (40.6%), A (3.1%), B (3.1%) and C (1.6%). Two cases of co-infection were identified: E/A (15.6%) and B/C (1.6%). Subgenotypes A1, B2 and C1 were highlighted. Conclusion: The prevalence of HBV is high, HBV infection remains a major public health problem for blood donors in Congo. Genotypes E, A, B, C as well as subtypes A1, B2, C1 have been identified in northern Congo.

Functional brain correlates of negative symptoms in schizophrenia assessed using a novel executive paradigm

In this study we used non-overlapping parts of the two long open reading frames coding for nonstructural (NS) and capsid (VP) proteins of all available sequences of the Parvovirus B19 subgenotype 1a genome and found out that the rates of A to G, C to T and A to T mutations are higher in the first long reading frame (NS) of the virus than in the second one (VP). This difference in mutational pressure directions for two parts of the same viral genome can be explained by the fact of transcription of just the first long reading frame during the lifelong latency in nonerythroid cells. Adenine deamination (producing A to G and A to T mutations) and cytosine deamination (producing C to T mutations) occur more frequently in transcriptional bubbles formed by DNA “plus” strand of the first open reading frame. These mutations can be inherited only in case of reactivation of the infectious virus due to the help of Adenovirus that allows latent Parvovirus B19 to start transcription of the second reading frame and then to replicate its genome by the rolling circle mechanism using the specific origin. Results of this study provide evidence that the genomes reactivated from latency make significant contributions to the variability of Parvovirus B19.

Recent and occult hepatitis B virus infections among blood donors in the United States.

Characteristics of US blood donors with recent (RBI) or occult (OBI) hepatitis B virus (HBV) infection are not well defined. Donors with RBI and OBI were identified by nucleic acid and serologic testing among 34.4 million donations during 2009-2015. Consenting donors were interviewed and their HBV S-gene sequenced. The overall rate of HBV-infected donors was 7.95 per 100,000; of these, 0.35 per 100,000 and 1.70 per 100,000 were RBI and OBI, respectively. RBI (n = 120) and OBI (n = 583) donors constituted 26% of all HBV-infected (n = 2735) donors. Detection of HBV DNA in 92% of OBI donors required individual donation nucleic acid testing. Donors with OBI compared to RBI were older (mean age, 48 vs 39 years; p < 0.0001) with lower median viral loads (9 vs. 529 IU/mL; p < 0.0001). A higher proportion of OBI than RBI donors were born or resided in an endemic country (39% vs. 5%; p = 0.0078). Seventy-seven percent of all RBI and OBI donors had multiple sex partners, an HBV-risk factor. Of 40 RBI and 10 OBI donors whose S gene was sequenced, 33 (83%) and 6 (60%), respectively, carried HBV subgenotype A2; 18 (55%) and 2 (33%), respectively, shared an identical sequence. Infection with 1 or more putative HBV-immune-escape mutants was identified in 5 (50%) of OBI but no RBI donors. RBI and OBI continue to be identified at low rates, confirming the importance of comprehensive HBV DNA screening of US blood donations. HBV-infected donors require referral for care and evaluation and contact tracing; their HBV strains may provide important information on emergent genotypes.

Genetic diversity of Bovine Viral Diarrhea Virus from cattle in Chile between 2003 and 2007

BackgroundBovine Viral Diarrhea Virus causes significant economic losses in cattle. BVDV has high genomic diversity, with two species, BVDV-1 and BVDV-2, and at least twenty-one subgenotypes for BVDV-1 and four subgenotypes for BVDV-2. Vaccines are important tools to reduce the economic losses caused by this virus. However, vaccine strains must correspond to the antigenic profile of the viruses present in the region where the vaccine is applied. A restricted phylogenetic study with 14 viruses isolated from cattle between 1993 and 2001 showed that the genetic profile of BVDV in Chile consisted of viruses of both species and sub-genotypes 1a, 1b, 1c (currently 1j) and 2a. To determine more accurately the genetic profile of BVDV in Chile, in this study a larger number of viruses obtained from bovines between 2003 and 2007 were typed.ResultsThe study was performed using partial sequences from the 5′ noncoding region (5’UTR) and E2 coding region of the viral genome of thirty-five Chilean viruses isolated from geographic regions that have 84.6% of the Chilean cattle. All tested viruses belonged to species BVDV-1. Eighteen viruses belonged to BVDV-1j subgenotype (51.4%), twelve belonged to BVDV-1b (34.3%) and five belonged to BVDV-1a (14.3%). The Chilean BVDV-1j viruses showed low genetic diversity, both among themselves and with the BVDV-1j present in other regions of the world. This could be explained by a relatively recent introduction of this viral subgenotype in cattle, which agrees with its low geographical distribution worldwide. Otherwise, Chilean BVDV-1b viruses grouped into a single cluster, different even than the viruses present in Argentina and Brazil, countries geographically close to Chile, a process of local evolution that could generate antigenic differences between the Chilean viruses and the viruses used as vaccine strains.ConclusionsThe high presence of viruses of the BVDV-1j subgenotype, which show major antigenic differences with BVDV-1a and BVDV-1b subgenotypes used in the commercial vaccines, suggest that BVDV-1j viruses could be an emergent subgenotype of BVDV in cattle in South America and suggest evaluating an update of the vaccines used in Chile.

Molecular Characterization of Near Full-Length Genomes of Hepatitis B Virus Isolated from Predominantly HIV Infected Individuals in Botswana.

The World Health Organization plans to eliminate hepatitis B and C Infections by 2030. Therefore, there is a need to study and understand hepatitis B virus (HBV) epidemiology and viral evolution further, including evaluating occult (HBsAg-negative) HBV infection (OBI), given that such infections are frequently undiagnosed and rarely treated. We aimed to molecularly characterize HBV genomes from 108 individuals co-infected with human immunodeficiency virus (HIV) and chronic hepatitis B (CHB) or OBI identified from previous HIV studies conducted in Botswana from 2009 to 2012. Full-length (3.2 kb) and nearly full-length (~3 kb) genomes were amplified by nested polymerase chain reaction (PCR). Sequences from OBI participants were compared to sequences from CHB participants and GenBank references to identify OBI-unique mutations. HBV genomes from 50 (25 CHB and 25 OBI) individuals were successfully genotyped. Among OBI participants, subgenotype A1 was identified in 12 (48%), D3 in 12 (48%), and E in 1 (4%). A similar genotype distribution was observed in CHB participants. Whole HBV genome sequences from Botswana, representing OBI and CHB, were compared for the first time. There were 43 OBI-unique mutations, of which 26 were novel. Future studies using larger sample sizes and functional analysis of OBI-unique mutations are warranted.

In Silico Analysis of Hepatitis B Virus Occult Associated Mutations in Botswana Using a Novel Algorithm.

Occult hepatitis B infections (OBI) represent a reservoir of undiagnosed and untreated hepatitis B virus (HBV), hence the need to identify mutations that lead to this phenotype. Functionally characterizing these mutations by in vitro studies is time-consuming and expensive. To bridge this gap, in silico approaches, which predict the effect of amino acid (aa) variants on HBV protein function, are necessary. We developed an algorithm for determining the relevance of OBI-associated mutations using in silico approaches. A 3 kb fragment of subgenotypes A1 and D3 from 24 chronic HBV-infected (CHB) and 24 OBI participants was analyzed. To develop and validate the algorithm, the effects of 68 previously characterized occult-associated mutations were determined using three computational tools: PolyPhen2, SNAP2, and PROVEAN. The percentage of deleterious mutations (with impact on protein function) predicted were 52 (76.5%) by PolyPhen2, 55 (80.9%) by SNAP2, and 65 (95.6%) by PROVEAN. At least two tools correctly predicted 59 (86.8%) mutations as deleterious. To identify OBI-associated mutations exclusive to Botswana, study sequences were compared to CHB sequences from GenBank. Of the 43 OBI-associated mutations identified, 26 (60.5%) were predicted by at least two tools to have an impact on protein function. To our knowledge, this is the first study to use in silico approaches to determine the impact of OBI-associated mutations, thereby identifying potential candidates for functional analysis to facilitate mechanistic studies of the OBI phenotype.

Genetic variability in coding regions of the surface antigen and reverse transcriptase domain of hepatitis B virus polymerase, Colombia, 2002-2014

Introduction: Despite the availability of an effective vaccine and treatment to reduce the viral load and progressive hepatocellular injury, approximately 240 million people worldwide are chronically infected with the hepatitis B virus (HBV). In Colombia, the circulation of different viral genotypes has been confirmed. Mutations in the genome have been associated to antiviral therapy resistance, viral escape to neutralizing antibodies, occult infection and progression to hepatocellular carcinoma. Objective: To identify the genotypes and the presence of mutations in the coding region of the surface (S) antigen and the reverse transcriptase (RT) domain of the polymerase of HBV obtained from serum samples for hepatitis B diagnosis received by the Instituto Nacional de Salud during the period 2002-2014. Materials and methods: A total of 495 serum samples with previous HBsAg reactive result were used for molecular detection. A fragment of 1,591 nucleotides was sequenced, and the corresponding phylogenetic analysis was performed. Results: We detected the viral genome of HBV in 66 samples and 28 were successfully sequenced. The phylogenetic analysis allowed the identification of subgenotypes F3 and A2. The L180M and M204V resistance mutations were simultaneously identified in one sample, while the I169L resistance mutation was identified in another one. A single escape mutation, P120Q, was identified in one more. Two samples showed a deletion of 105 nucleotides in the preS1-preS2 region. Conclusions: The circulation of genotypes/subgenotypes F3 and A2 of HBV in Colombia was corroborated, as well as the presence of some resistance and escape mutations. The present study constitutes a contribution to the molecular epidemiology of HBV in Colombia.

Molecular characterization of hepatitis B virus (HBV) in African children living in Australia identifies genotypes and variants associated with poor clinical outcome.

Migration from sub-Saharan Africa is contributing to the rising incidence of chronic hepatitis B (CHB) infection and its complications in Australia. African CHB is associated with unique genotypes, such as E and A1, which are associated with reduced vaccine efficacy and early-onset hepatocellular carcinoma, respectively, although the prevalence of these genotypes outside Africa is poorly described. Treatment-naïve children of African origin with CHB were recruited at the Royal Children's Hospital Melbourne. Population-based sequencing of the complete HBV genome, or the clinically relevant basal core promoter (BCP)/precore (PC) region, was performed, and the HBV genotype/subgenotype assigned by phylogenetic analysis. HBV was characterized in serum from 67 children, median age 12.5 years. HBV genotype E was most frequent (70 %), with genotype D [25 %; subgenotypes D6 (formerly D7)/D3/D2)] and subgenotype A1 (5 %) also being identified. Despite their young age, over 50 % of the children were HBeAg-negative and had seroconverted to anti-HBe, with this being associated with canonical BCP/PC mutations in the majority of cases. The profile of HBV in African children living in Australia was characterized by early HBeAg seroconversion and infection with HBV variants associated with poor clinical outcome, as well as genotypes previously associated with reduced vaccine efficacy or rapid progression to liver cancer. These findings have important ramifications for patient monitoring and treatment guidelines in the Australian paediatric setting.

Sub-optimal protection against past hepatitis B virus infection where subtype mismatch exists between vaccine and circulating viral genotype in northern Australia

BackgroundIn Australia’s Northern Territory, the hepatitis B virus (HBV) subgenotype A2 (subtype adw2) vaccine was introduced in 1988 for Indigenous infants. Subsequently, the circulating viral genotype has been identified as subgenotype C4 (subtype ayw3). We assessed HBV vaccine effectiveness (VE) in light of this subtype mismatch. MethodsParticipants of the Aboriginal Birth Cohort (ABC) study were recruited at birth (1987–1990), with HBV serology obtained at follow-up waves 3 (2005–2007) and 4 (2013–2015). Participants were immune if HBV surface antibody levels exceeded 10 IU/L. We determined the VE against any HBV infection (anti-HBc+) and against chronic infection (HBsAg+ or HBV DNA+), comparing non-vaccinated participants with those fulfilling United States Centers for Disease Control and Prevention (CDC) criteria for full HBV immunisation. ResultsOf 686 participants in the ABC study, we obtained HBV serology from 388 at wave 4. 181 participants were immune to HBV and 97 had evidence of any infection. Seven participants were chronically infected, of whom five had received three vaccine doses, and anti-HBc seroconversion had occurred subsequent to the three vaccine doses for two of these seven participants. Comparing the 107 participants who had been vaccinated in accordance with CDC recommendations and 127 who had not been vaccinated, VE against any infection was 67% (95%CI, 43–104%). The odds of being anti-HBc+ was 87% lower in participants raised in urban settings compared to those born into families from remote areas (OR, 0.1; 95%CI, 0.03–0.4). ConclusionsIn a setting where there exists a subtype mismatch between vaccine and circulating genotype, the vaccine was largely effective in preventing chronic infection but sub-optimal against any infection. The implications of a high prevalence of anti-HBc seropositivity in this population are unclear and require further study. The fact that anti-HBc seropositivity was strongly associated with remote dwelling suggests ongoing viral exposure in remote settings.

Hepatitis E virus infection in different groups of Estonian patients and people who inject drugs

BackgroundPreviously we demonstrated a high prevalence of hepatitis E virus (HEV) in domestic pigs and wild boars, the main reservoir and possible source of HEV infections in humans. But so far there are no reports about spread of HEV in Estonian human population. ObjectivesThe present study aimed to determine the prevalence and genotyping of HEV in different groups of the Estonian adult population. Study designTotally 1426 human serum samples were tested (763 patients with clinically diagnosed nonA/B/C hepatitis, 176 hemodialysis patients, 282 patients with suspected HEV infection and 205 people who injected drugs (PWID)). Presence of anti-HEVantibodies was assessed by ELISA and confirmed by immunoblotting. All anti-HEV positive sera were analyzed for RNA by qPCR. Amplified ORF2 region was sequenced and used for phylogenetic analysis. ResultsAntibody assay revealed 49 samples from 1426 (3.4%) with acute (17) or past (32) HEV infection. HEV RNA was detected in 10 anti-HEV IgM positive samples, including 9 samples from patients with suspected HEV infection and 1 hemodialysis patient. Anti-HEV IgG were found in 7.8% patients with suspected HEV infection, in 4% hemodialysis patients, in 2.4% PWID and in 1.96% patients with nonA/B/C hepatitis. All groups demonstrated a trend to share of anti-HEV seroprevalence increasing with age. Phylogenetic analysis of 9 HEV RNA sequences revealed that 3 sequences belonged to HEV genotype 1; 6 ones to genotype 3 (1 sequence belonged to sub-genotype 3a, two ones – sub-genotype 3e, and three ones – to sub-genotype 3f). ConclusionsDespite the high seroprevalence among domestic pigs, no evidence of HEV transmission from Estonian pigs to humans was found. The results of our study suggest that HEV infections in Estonia are most likely associated with travel or with consumption of imported food products.

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

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