Hepatitis B genotypes/subgenotypes and MHR variants among Moroccan chronic carriers

Virological characterization of Hepatitis B virus infection in Morocco: A ten-years study (2014 - 2023)

In alignment with Morocco's national strategy for eliminating viral hepatitis, we aimed to characterize and update the virological profile of chronic hepatitis B patients. Demographic, serological and molecular parameters of 804 HBsAg-positive patients were retrospectively analyzed. Overall, 58.24 % were HBV-positive (55.37 % males, p = 0.74). The median age was 46 years (37-57). Patients ≤ 24 years comprised 5 % of HBsAg-positive and 4.34 % of HBV-positive cases. The median viral load was 2.62 log10 IU/mL (1.87-3.44). The prevalent genotypes were D (91.04 %), A (7.55 %) and E (1.41 %). Liver enzymes were normal in most of cases. 91.04 % of patients were HBeAg-negative, with 92.23 % having genotype D (p < 0.001). Co-infection rates with other hepatitis viruses were low. Significant associations were found between HBeAg-negative status, genotype D, viral load, and liver enzyme levels (p < 0.001). We highlighted the need for prenatal HBsAg screening for pregnant women and prioritizing the birth-dose vaccine to prevent mother-to-child transmission, especially after the COVID-19 pandemic.

Prevalence of Hepatitis B Virus Infection Markers among Patients of the Ibn Sina University Hospital Center (Rabat, Morocco)

INTRODUCTION

Viral hepatitis B is a global scourge affecting millions of people worldwide. In Morocco, hepatitis B is considered a public health problem, and available data converge to consider Morocco as a country with intermediate endemicity. In the present study, we have planned to evaluate the HBV prevalence in Morocco on a large scale and to assess the prevalence of different serological markers for better management of this infection in Morocco.

METHODS

This study was conducted on 18,877 patients referring to the Ibn Sina University Hospital Center of Rabat, Morocco. HBV serological markers including HBsAg, HBsAb, HBeAg, HBeAb, and total HBcAb were assessed by immune-enzymatic assays. The quantification of HBV DNA was performed by real-time PCR.

RESULTS

The overall prevalence of positive cases for HBsAg, HBsAb, and total HBcAb was 2.47%, 27.66%, and 21.2%, respectively. From 141 patients with an isolated HBcAb serological profile (HBcAb+/HBsAb-/HBsAg-), HBV DNA was detected in 10 patients, representing a rate of 7.09%. In the present study, up to 95.78% of HBV chronic carriers were negative for HBeAg.

CONCLUSION

This study highlights a higher prevalence of HBsAg in the hospital-based population than the general population reported previously in Morocco and a very low HBV immunization coverage. Of particular interest, detectable HBV DNA levels in isolated HBcAb patients show that exclusive HBsAg screening cannot eliminate the risk of HBV transmission in certain cases. Many efforts are then mandatory to promote serological testing and increase the vaccination rate to limit viral dissemination for better management of this disease in Morocco.

Molecular epidemiology, phylogenetic analysis and genotype distribution of hepatitis B virus in Saudi Arabia: Predominance of genotype D1

Despite the implementation of various vaccination programs, hepatitis B virus (HBV) poses a considerable health problem in Saudi Arabia. Insight on HBV evolutionary history in the region is limited. We performed a comprehensive epidemiological and phylogenetic reconstruction based on a large cohort of HBV infected patients. Three hundred and nineteen HBV-infected patients with different clinical manifestations, including inactive and active chronic carriers and patients with cirrhosis and hepatocellular carcinoma (HCC), were enrolled in this study. The full-length large S gene was amplified and sequenced. Phylogenetic analysis was performed to determine the genotype and subgenotypes of the isolates. Phylogenetic tree analysis revealed that genotype D is the most dominant genotype among patients. Moreover, this analysis identified two strains with genotype E isolated from active carriers. Detailed phylogenetic analyses confirmed the presence of four HBV D subgenotypes, D1 (93%, n = 296), D2 (0.02%, n = 5), D3 (0.003%, n = 1), and D4 (0.003%, n = 1). In addition, six genotype D strains were not assigned to any existing HBV D subgenotype. The large S gene of eight strains showed signatures of genotype recombination between the genotypes D and A and between D and E. Several strains harbored medically important point mutations at the protein level. Along with the dominance of the HBV genotype D, isolation of the E genotype and several recombinant strains from patients with Saudi Arabian origin is an essential result for decisions involving therapeutic measures for patients. Development of vaccines and detection of diagnostic escape mutations at antigenic epitopes on the HBsAg will be valuable to public health authorities. Furthermore, the diversity at the nucleotide and amino acid levels and different proportions of dN/dS at the PreS1, PreS2, and HBsAg reveal the selective pressure trend from inactive status towards advanced liver diseases.

High Prevalence of Hepatitis B Subgenotype D4 in Northeast Brazil: an Ancient Relic from African Continent?

INTRODUCTION

Hepatitis B virus (HBV) infection leads to a chronic liver disease that is distributed worldwide. The characterization of HBV into genotypes/subgenotypes is not only a mere procedure for distinguishing different HBV strains around the world because determining their geographic distribution is crucial to understanding their spread across the world.

MATERIAL AND METHODS

We characterized different HBV genotypes and subgenotypes in five municipalities located in northeastern Maranhão, in the Brazilian north Atlantic coast. 92 HBsAg-positive individuals were submitted to PCR (polymerase chain reaction). Fifty samples were sequenced using automated Sanger sequencing and classified by phylogenetic methods.

RESULTS

Subgenotypes D4 and A1 were found in 42 (84%) and eight (16%) samples, respectively. To our knowledge, this is the first study to describe a high frequency of subgenotype D4 in any population. Subgenotype A1 is frequently found across Brazil, but D4 has been rarely detected and only in a few Brazilian states. This study shows the characterization of HBV subgenotypes from a population based study in the state of Maranhão, particularly in populations that do not have frequent contact with populations from other regions of the world.

CONCLUSION

Our findings showed a HBV subgenotype profile that probably reflect the viruses that were brought with the slave trade from Africa to Maranhão. This study also reinforces the need to evaluate the status of HBV dispersion not only in large urban centers, but also in the hinterland, to enable the implementation of effective control and treatment measures.

Hepatitis B virus and hepatitis delta virus subtypes circulating in Algeria and seroprevalence of HDV infection

BACKGROUND

Little is known about molecular characteristics of HBV strains circulating in Algeria and there are few data regarding HDV infection.

OBJECTIVES

The aim of this study is to describe the genetic diversity of HBV and HDV strains existing in Algeria and to determine the seroprevalence of HDV infection.

STUDY DESIGN

Plasma samples from 134 patients were analyzed by enzyme immunoassay method for HBV and HDV serological markers. Genotyping of HBV and HDV strains were performed using direct sequencing followed by phylogenetic analyses of the PreS1 and R0 region of the HBV and HDV genome respectively.

RESULTS

The PreS1 gene was successfully amplified in 119 patients (82 males and 37 females). Phylogenetic analysis of HBV strains revealed the presence of genotypes D (86.5%) and A2 (11.76%). The subgenotypes D are distributed as follows: HBV/D7 (43.5%), HBV/D3 (24.75%), HBV/D1 (16.8%) and HBV/D2 (14.85%). A recombinant between genotypes A, E and D was found. The seroprevalence of HDV infection among HBV carriers was less than 5.35%. Only one isolate of HDV genotype 1 was identified.

CONCLUSIONS

Our data indicate the predominance of HBV subgenotype D7 and a low prevalence of HDV infection.

Unravelling the history of hepatitis B virus genotypes A and D infection using a full-genome phylogenetic and phylogeographic approach

Hepatitis B virus (HBV) infection constitutes a global public health problem. In order to establish how HBV was disseminated across different geographic regions, we estimated the levels of regional clustering for genotypes D and A. We used 916 HBV-D and 493 HBV-A full-length sequences to reconstruct their global phylogeny. Phylogeographic analysis was conducted by the reconstruction of ancestral states using the criterion of parsimony. The putative origin of genotype D was in North Africa/Middle East. HBV-D sequences form low levels of regional clustering for the Middle East and Southern Europe. In contrast, HBV-A sequences form two major clusters, the first including sequences mostly from sub-Saharan Africa, and the second including sequences mostly from Western and Central Europe. Conclusion: We observed considerable differences in the global dissemination patterns of HBV-D and HBV-A and different levels of monophyletic clustering in relation to the regions of prevalence of each genotype.

Genetic variation of hepatitis B surface antigen among acute and chronic hepatitis B virus infections in The Netherlands

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

Characterization of hepatitis B virus in Amerindian children and mothers from Amazonas State, Colombia

BACKGROUND

Hepatitis B Virus (HBV) infection is a worldwide public health problem. In the 1980's a highly effective and safe vaccine against HBV was developed, although breakthrough infection still occasionally occurs because of the emergence of escape mutants. The aim of this study was to identify HBV genotypes and escape mutants in children and their mothers in Amerindian communities of the Amazonas State, Southern Colombia.

METHODS

Blood specimens collected from children and mothers belonging to 37 Amerindian communities in Amazonas state, were screened for HBsAg and anti-HBc using ELISA. The partial region containing the S ORF was amplified by nested PCR, and amplicons were sequenced. The phylogenetic analysis was performed using the MEGA 5.05 software.

RESULTS

Forty-six children (46/1275, 3.6%) and one hundred and seventy-seven mothers (177/572, 30.9%) were tested positive for the anti-HBc serological marker. Among them, 190 samples were tested for viral genome detection; 8.3% (2/31) serum samples obtained from children and 3.1% (5/159) from mothers were positive for the ORF S PCR. The predominant HBV genotype in the study population was F, subgenotype F1b; in addition, subgenotype F1a and genotype A were also characterized. Two HBV escape mutants were identified, G145R, reported worldwide, and W156*; this stop codon was identified in a child with occult HBV infection. Other mutations were found, L109R and G130E, located in critical positions of the HBsAg sequence.

CONCLUSIONS

This study aimed to characterize the HBV genotype F, subgenotypes F1b and F1a, and genotype A in Amerindian communities and for the first time escape mutants in Colombia. Further investigations are necessary to elucidate the frequency and the epidemiological impact of the escape mutants in the country.

Myxovirus resistance 1 gene polymorphisms and outcomes of viral hepatitis B and C infections in Moroccan patients

Host genetic factors may influence the establishment of chronicity or spontaneous clearance in viral hepatitis B and C infections. More light was shed on the role played by interferon-stimulated genes in the innate immunity. Myxovirus resistance 1 (MX1) is one of those key genes that have reported to inhibit several viruses. The present study aims to explore the possible association of -88G/T and -123C/A promoter variants of MX1 with susceptibility to chronic hepatitis B and C and/or with spontaneous clearance in a Moroccan population. The -88G/T and -123C/A SNPs were genotyped by PCR-RFLP in 538 individuals stratified into HBV chronically infected patients (n = 120), HCV-chronically infected patients (n = 115), HBV spontaneously resolved subjects (n = 114), HCV spontaneously resolved group (n = 52), and healthy controls (n = 137). A significant association of -123C allele with HBV spontaneous clearance has been found (P = 0.002, OR = 2.34; 95%CI [1.36-4]). In addition, a significant correlation between the MX1-GC haplotype and HBV spontaneous clearance (P < 0.001) was found. No significant association of -88G/T and -123C/A polymorphisms with regard to HCV infection was observed in this study. Here, we show that for North African patients with chronic hepatitis, MX1 gene variation at position -123 may influence the outcome of HBV infection but not HCV infection. J. Med. Virol. 89:647-652, 2017. © 2016 Wiley Periodicals, Inc.

Evaluation of the G145R Mutant of the Hepatitis B Virus as a Minor Strain in Mother-to-Child Transmission

The role of the hepatitis B virus (HBV) mutant G145R, with a single change in amino acid 145 of the surface protein, as a minor population remains unknown in mother-to-child transmission. The minor strain as well as the major strain of the G145R mutant were evaluated in three cohorts using a locked nucleic acid probe-based real-time PCR. The breakthrough cohort consisted of children who were born to HBV carrier mothers and became HBV carriers despite immnoprophylaxis (n = 25). The control cohort consisted of HBV carriers who had no history of receiving the hepatitis B vaccine, hepatitis B immunoglobulin or antiviral treatment (n = 126). The pregnant cohort comprised pregnant women with chronic HBV infection (n = 31). In the breakthrough cohort, 6 showed positive PCR results (major, 2; minor, 4). In the control cohort, 13 showed positive PCR results (major, 0; minor, 13). HBeAg-positive patients were prone to have the G145R mutant as a minor population. Deep sequencing was performed in a total of 32 children (PCR positive, n = 13; negative, n = 19). In the breakthrough cohort, the frequency of the G145R mutant ranged from 0.54% to 6.58%. In the control cohort, the frequency of the G145R mutant ranged from 0.42% to 4.1%. Of the 31 pregnant women, 4 showed positive PCR results (major, n = 0; minor, n = 4). All of the pregnant women were positive for HBeAg and showed a high viral load. Three babies born to 3 pregnant women with the G145R mutant were evaluated. After the completion of immunoprophylaxis, 2 infants became negative for HBsAg. The remaining infant became negative for HBsAg after the first dose of HB vaccine. G145R was detected in one-fourth of the children with immunoprophylaxis failure. However, the pre-existence of the G145R mutant as a minor population in pregnant women does not always cause breakthrough infection in infants.

Evolutionary dynamics of HBV-D7 subgenotype in Tunisia

Hepatitis B virus (HBV) is the main cause of diseases liver related infecting more than 200 milion persons worldwide. HBV infection shows high level of prevalence in South-East Europe and in Mediterranean basin. In Tunisia, a country with an intermediate level endemicity, HbsAg prevalence ranges from 2 to 5%. Most of the HBV isolates from Tunisia were classified as subgenotype D7 whose circulation is restricted to a specific area of North Africa including Maghreb region. In this paper, the phylogeny of HBV-D7 isolated from 38 Tunisian patients was investigated by analyzing the S gene region of HBV. A Bayesian coalescent-based framework was used to estimate the origin of the HBV-D7 in the country. The Tunisian D7 isolates were found to share a common ancestor whose origin was traced back to 1958. Population dynamics indicated that HBV-D7 epidemic in Tunisia grew exponentially from 1960s to 1990s. After that, the curve reached a plateau around the years 2000 likely due to the implementation of the infant vaccination program in 1996. Epidemiological data suggested that the exponential growth phase was likely sustained by intra-familial transmission events occurring during infancy. Further characterization of HBV-D7 isolates should be performed to evaluate, in the post-vaccination era, the emergence of new transmission routes, and to monitor the efficacy of the vaccination program. J. Med. Virol. 89:469-475, 2017. © 2016 Wiley Periodicals, Inc.

Naturally Occurring Surface Antigen Variants of Hepatitis B Virus in Tunisian Patients

In Tunisia, the prevalence of naturally occurring surface (S) gene variants of hepatitis B virus (HBV) has not been determined. In the present study, the prevalence of these variants was examined in terms of the clinical and viral state in a series of 99 Tunisian patients with HBV infection. The S genes were amplified and directly sequenced. Genotype D was predominant (98%), 40.4% isolates belonged to subgenotypes D7 and 1 to subgenotype D2. The most common subtype was ayw2 (95.9%). In total, 60.6% of the studied strains harbored S mutations. Several novel mutation patterns were detected. Interestingly, the presence of S mutations was significantly correlated with the D7 subgenotype, low HBV DNA and advancing age (≥35 years), and tended to be higher in liver cirrhosis than in chronic infection. The global prevalence of the major hydrophilic region variants was 12.1%, with substitution S143L/T as the most frequent (4%). Only 33.9% of S substitutions produced amino acid changes in the polymerase gene. In conclusion, a high prevalence of naturally occurring HBsAg variants was observed among Tunisian HBV carriers. Natural viral variability in a geographical region and duration of infection are among the major factors associated with the occurrence of S mutations.

An evaluation of entecavir treatment among nucleos(t)ide-naïve Moroccan patients with chronic hepatitis B

OBJECTIVE

To analyse the efficacy and safety of entecavir (ETV) treatment in nucleos(t)ide (NUC)-naïve Moroccan patients with chronic hepatitis B.

METHODS

We retrospectively analysed 41 NUT-naïve Moroccan patients with chronic hepatitis B who received ETV 0,5 mg/day monotherapy for at least 3 months, of whom 3 were HBV envelope antigen (HbeAg) positive and 38 were HBeAg negative. The primary end point was the proportion of patients achieving virological response. Secondary end points included biochemical response (alanine transaminase (ALT) normalisation), serological response (HbeAg and HBV surface antigen (HBsAg) loss or seroconversion) and safety.

RESULTS

The median follow-up duration was 74 weeks (48-144 weeks) and mean age was 43.8 years. Of 41 patients, 6 were primary non-responders and 2 achieved partial virological response at week 48, whereas 35 achieved undetectable hepatitis B virus (HBV) DNA at month 12. Viral suppression was maintained in 97.6% of patients after 3 years of ETV treatment. One patient experienced a virological breakthrough at month 12 of treatment. ALT normalisation occurred in 100% of the patients after 1 year of treatment. Only three patients in our study were HbeAg positive, of whom one has experienced seroconversion at month 12 of treatment. However, HBsAg loss or seroconversion was not achieved during the period of the study. No serious adverse event was reported.

CONCLUSIONS

These preliminary results showed that ETV is a safe and potent inhibitor of HBV in NUC-naïve Moroccan patients, but we need to observe more patients for a longer period of time, in order to assess the long-term effectiveness, safety, resistance profile and predictive factors for virological and serological response of ETV.

Prevalence of mutations within major hydrophilic region of hepatitis B virus and their correlation with genotypes among chronically infected patients in Egypt

BACKGROUND AND STUDY AIMS

Mutations within the major hydrophilic region (MHR) of the hepatitis B surface antigen (HBsAg) have been reported in relation to viral persistence by evasion from vaccine and immunotherapy, severity of liver disease and lack of detection by commercial kits. The aim of this study was to elucidate the circulation of hepatitis B virus (HBV) genotypes, subgenotypes and serotypes in Egypt, with recognition of the pattern and prevalence of MHR mutations possibly occurring during the course of the disease.

PATIENTS AND METHODS

Eighty-eight samples from patients with chronic HBV infection were included in the study. The surface protein-encoding gene (S gene) in the HBV genome was subjected to amplification and partial sequencing.

RESULTS

Based on phylogenetic analysis, only genotype D was found circulating among patients. The majority of isolates belonged to subgenotype D3 (86.3%), followed by D7 (8%), then D5 (3.4%) and lastly D1 (2.3%). Two subtypes were identified: ayw2 (97%) and ayw3 (2%). The 'w' sub-determinant was not defined in one isolate (1%). A significant proportion of patients (13/88, 14.8%) exhibited mutations in the MHR, 10 of whom harboured mutations in the 'a' determinant region and three outside. The first loop comprised four patients with three mutations (P127S, P127T and Y134F). The second loop contained six patients, all with one mutation, S143L, which was most frequently encountered in this study (6.8%).

CONCLUSIONS

We conclude that genotype D, subgenotype D3 and HBsAg subtype ayw2 are the most common types circulating in Egypt, which account for 100%, 86.3% and 97% of the population, respectively, with a moderate degree of MHR mutations.

Mutations in pre-core and basic core promoter regions of hepatitis B virus in chronic hepatitis B patients

AIM: To investigate the frequency of mutations in pre-core (pre-C) and basic core promoter (BCP) regions of hepatitis B virus (HBV) from Shanxi Province, and the association between mutations and disease related indexes.

METHODS: One hundred chronic hepatitis B patients treated at Shanxi Province Hospital of Traditional Chinese Medicine were included in this study. PCR-reverse dot blot hybridization and mismatch amplification mutation assay (MAMA)-PCR were used to detect the mutations in the HBV pre-C and BCP regions. HBV DNA content and liver function were compared between patients with mutant HBV pre-C and BCP loci and those with wild-type loci. The consistency between PCR-reverse dot blot hybridization and MAMA-PCR for detecting mutations in the HBV pre-C and BCP regions was assessed.

RESULTS: Of the 100 serum samples detected, 9.38% had single mutations in the pre-C region, 29.17% had single mutations in the BCP region, 41.67% had mutations in both BCP and pre-C regions, and 19.79% had wild-type loci. The rates of BCP and pre-C mutations were 65.7% and 34.3%, respectively, in hepatitis B e antigen (HBeAg) positive patients, and 84.6% and 96.2%, respectively, in HBeAg negative patients. The rate of pre-C mutations was significantly higher in HBeAg negative patients than in HBeAg positive patients (χ² = 26.62, P = 0.00), but there was no significant difference in the distribution of mutations in the BCP region between HBeAg positive and negative patients (χ² = 2.43, P = 0.12). The presence of mutations in the pre-C (Wilcoxon W = 1802.5, P = 0.00) and BCP regions (Wilcoxon W = 2906.5, P = 0.00) was more common in patients with low HBV DNA content. Both AST and GGT were significantly higher in patients with mutant pre-C and BCP loci than in those with wild-type loci (P < 0.05). PCR-reverse dot blot hybridization and MAMA-PCR for detection of mutations in the BCP and pre-C regions had good consistency, and the Kappa values obtained were 0.91 and 0.58, respectively.

CONCLUSION: HBeAg negative patients tend to have HBV pre-C mutations. However, these mutations do not cause increased DNA copies, but associate with damage of liver function.

Hepatitis B virus burden in developing countries

Hepatitis B virus (HBV) infection has shown an intermediate or high endemicity level in low-income countries over the last five decades. In recent years, however, the incidence of acute hepatitis B and the prevalence of hepatitis B surface antigen chronic carriers have decreased in several countries because of the HBV universal vaccination programs started in the nineties. Some countries, however, are still unable to implement these programs, particularly in their hyperendemic rural areas. The diffusion of HBV infection is still wide in several low-income countries where the prevention, management and treatment of HBV infection are a heavy burden for the governments and healthcare authorities. Of note, the information on the HBV epidemiology is scanty in numerous eastern European and Latin-American countries. The studies on molecular epidemiology performed in some countries provide an important contribution for a more comprehensive knowledge of HBV epidemiology, and phylogenetic studies provide information on the impact of recent and older migratory flows.

Hepatitis B Virus Genotype D Isolates Circulating in Chapecó, Southern Brazil, Originate from Italy

Hepatitis B virus genotype A1 (HBV/A1), of African origin, is the most prevalent genotype in Brazil, while HBV/F predominates in the other South American countries. However, HBV/D is the most common in the three states of southern Brazil, where ‘islands’ of elevated prevalence, as Chapecó and other cities, have been described. In this study, 202 HBV chronic carriers attending in 2013 the viral hepatitis ambulatory of Chapecó, were investigated. In comparison with previous studies performed in the same ambulatory, a rapid aging of the HBV infected population was observed (mean age of the newly diagnosed patients increasing from 29.9 ± 10.3 years in 1996 to 44.4 ± 13.3 years in 2013), probably due to a singular vaccination schedule at Chapecó that included not only children but also adolescents. Phylogenetic and BLAST analyses (S region) classified 91 HBV isolates into genotypes A (n = 3) and D (n = 88). The majority of HBV/D isolates were closely related to D3 sequences. To understand the reasons for the absence or near absence of genotypes A and F, and how HBV/D was introduced in the south of Brazil, HBV/D infected patients were inquired about their genealogical and geographical origins. Forty-three (52%) patients have their four grandparents of Italian origin, vs. seven (8%) who have their four grandparents of Brazilian origin. At all, 65 out of 83 (78%) patients had at least one grandparent originating from Italy. Taking into consideration the fact that Italy is one of the few countries where subgenotype D3 is predominant, the results strongly suggested that HBV/D was introduced in Brazil through Italian immigration which culminated between 1870 and 1920.

The prevalence of mutations in the major hydrophilic region of the surface antigen of hepatitis B virus varies with subgenotype

Mutations in the major hydrophilic region (MHR) of the surface antigen of hepatitis B virus (HBV) may result in vaccine escape, failure of immunotherapy and antiviral resistance. These mutants may be transmitted and constitute a public health threat. We aimed to determine the prevalence of MHR mutations of HBV in areas of high endemicity in Guangxi, China. HBV surface gene was analysed from 278 HBsAg-positive asymptomatic individuals recruited from Guangxi using cluster sampling. Three genotypes, B, C and I, were identified. The overall prevalence of MHR mutations is 17·6%. The prevalence of MHR mutations in genotype B (15·1%) is not significantly different from that in genotype C (16·4%). However, the prevalence in subgenotype C5 (31·1%) is significantly higher than in subgenotype C2 (13·0%) (χ2= 6·997,P< 0·05). The prevalence of escape mutations and overlapping polymerase substitutions in subgenotype C5 is significantly higher than in subgenotypes B2 and C2. In total, 7·9% of MHR mutants are escape mutations and 72·1% of MHR mutations produced amino-acid changes in the overlapping polymerase, including resistance mutations to entecavir. Our results suggest that the prevalence of MHR mutations varies with subgenotype. The prevalence of escape mutations and polymerase mutations may be associated with subgenotype.

HBV genotypic variability in Cuba

The genetic diversity of HBV in human population is often a reflection of its genetic admixture. The aim of this study was to explore the genotypic diversity of HBV in Cuba. The S genomic region of Cuban HBV isolates was sequenced and for selected isolates the complete genome or precore-core sequence was analyzed. The most frequent genotype was A (167/250, 67%), mainly A2 (149, 60%) but also A1 and one A4. A total of 77 isolates were classified as genotype D (31%), with co-circulation of several subgenotypes (56 D4, 2 D1, 5 D2, 7 D3/6 and 7 D7). Three isolates belonged to genotype E, two to H and one to B3. Complete genome sequence analysis of selected isolates confirmed the phylogenetic analysis performed with the S region. Mutations or polymorphisms in precore region were more common among genotype D compared to genotype A isolates. The HBV genotypic distribution in this Caribbean island correlates with the Y lineage genetic background of the population, where a European and African origin prevails. HBV genotypes E, B3 and H isolates might represent more recent introductions.

Epidemiology of HBV subgenotypes D

The natural history of hepatitis B virus infection is not uniform and affected from several factors including, HBV genotype. Genotype D is a widely distributed genotype. Among genotype D, several subgenotypes differentiate epidemiologically and probably clinically. D1 is predominant in Middle East and North Africa, and characterized by early HBeAg seroconversion and low viral load. D2 is seen in Albania, Turkey, Brazil, western India, Lebanon, and Serbia. D3 was reported from Serbia, western India, and Indonesia. It is a predominant subgenotype in injection drug use-related acute HBV infections in Europe and Canada. D4 is relatively rare and reported from Haiti, Russia and Baltic region, Brazil, Kenya, Morocco and Rwanda. Subgenotype D5 seems to be common in Eastern India. D6 has been reported as a rare subgenotype from Indonesia, Kenya, Russia and Baltic region. D7 is the main genotype in Morocco and Tunisia. D8 and D9 are recently described subgenotypes and reported from Niger and India, respectively. Subgenotypes of genotype D may have clinical and/or viral differences. More subgenotype studies are required to conclude on subgenotype and its clinical/viral characteristics.

Enigmatic origin of hepatitis B virus: An ancient travelling companion or a recent encounter?

Hepatitis B virus (HBV) is the leading cause of liver disease and infects an estimated 240 million people worldwide. It is characterised by a high degree of genetic heterogeneity because of the use of a reverse transcriptase during viral replication. The ten genotypes (A-J) that have been described so far further segregate into a number of subgenotypes which have distinct ethno-geographic distribution. Genotypes A and D are ubiquitous and the most prevalent genotypes in Europe (mainly represented by subgenotypes D1-3 and A2); genotypes B and C are restricted to eastern Asia and Oceania; genotype E to central and western Africa; and genotypes H and F (classified into 4 subgenotypes) to Latin America and Alaska. This review summarises the data obtained by studying the global phylodynamics and phylogeography of HBV genotypes, particularly those concerning the origin and dispersion histories of genotypes A, D, E and F and their subgenotypes. The lack of any consensus concerning the HBV substitution rate and the conflicting data obtained using different calibration approaches make the time of origin and divergence of the various genotypes and subgenotypes largely uncertain. It is hypothesised that HBV evolutionary rates are time dependent, and that the changes depend on the main transmission routes of the genotypes and the dynamics of the infected populations.

Molecular characterization of hepatitis B virus (HBV) strains circulating in the northern coast of the Persian Gulf and its comparison with worldwide distribution of HBV subgenotype D1

Iran is a large country that covers the northern coast of the Persian Gulf. Iranian residents of this coastal region interact closely with people from neighboring countries because of historical and cultural relationships, as well as economic activities. In addition, the inhabitants of this border region have experienced several wars, which have affected public health infrastructures. This study characterized for the first time, the evolution of the full-length genome of HBV strains in asymptomatic carrier patients living in this particular region. In addition, this study was compared and complemented by a comprehensive evolutionary analysis of the worldwide geographical distribution of HBV subgenotype D1. Evolutionary analysis demonstrates that patients living in the northern coast of the Persian Gulf are mainly infected with HBV subgenotype D1, subtype ayw2. Specific mutations related to advanced liver disease were found more frequently in these strains compared to other strains isolated from asymptomatic carriers from other regions of Iran. This global comprehensive analysis showed that HBV subgenotype D1 strains have a worldwide distribution and that human mobility and immigration had a large impact on dispersal of HBV subgenotype D1, subtype ayw2 in Middle Eastern countries such as Iran, Syria, and Turkey. In addition to association of subtype ayw2 with subgenotype D1, it was demonstrated that other HBV subtypes like adw2, ayw1, and ayw3 are associated with HBV subgenotype D1 in different regions of the world. This study also revealed a remarkable distribution of subgenotype D1, subtype ayw4 although this particular subtype is associated with subgenotype D4 of HBV in European countries.

Evaluation of PCR-RFLP in the Pre-S Region as Molecular Method for Hepatitis B Virus Genotyping

BACKGROUND

Hepatitis B virus (HBV) infection is a public health problem in developing countries. HBV genotypes play major role in the evolution of infection since they were involved in different clinical presentations and response to treatment.

OBJECTIVES

This study was conducted to evaluate the efficiency of restriction fragment length polymorphism (RFLP) analysis for HBV genotyping.

PATIENTS AND METHODS

We investigated 98 samples collected from patients chronically infected with HBV. HBV genotypes were determined by analysis of patterns obtained after amplification in Pre-S region and digestion of the amplicon by two endonucleases AvaII and DpnII. Obtained results were confirmed by partial sequencing in the same region.

RESULTS

Two different HBV genotypes were detected in this study, Genotype D (in 95. 9%) and Genotype A (in 4.1%). Seventy-four samples (75.5%) were successfully genotyped with RFLP analysis and all classified as genotype D. The remaining 24 samples (24.5%) which were un-genotyped by RFLP analysis, were classified by partial sequencing of the pre-S region as HBV genotype D (20 samples, 20.4%) and genotype A (4 samples, 4.1%). Atypical profiles were significantly associated with advanced liver disease (P = 0.001) as well as older age (P < 0.05).

CONCLUSIONS

Several previous studies used PCR-RFLP to genotype HBV; however, we showed the high risk to obtain atypical profiles, especially in advanced stages of chronic infection, with as results difficulties to genotype the virus. These profiles resulted from the accumulation of mutations during natural course of infection resulting in a modification in restriction sites for enzymes. So, we recommended completing the investigation by partial sequencing to confirm obtained results.

Disparate distribution of hepatitis B virus genotypes in four sub-Saharan African countries

BACKGROUND

Hepatitis B virus (HBV) places a substantial health burden on Africa. Here, we investigated genetic diversity of HBV variants circulating in 4 countries of sub-Saharan Africa using archived samples. In total, 1492 plasma samples were tested from HIV-infected individuals and pregnant women, among which 143 (9.6%) were PCR-positive for HBV DNA (Côte d'Ivoire, 70/608 [11.5%]; Ghana, 13/444 [2.9%]; Cameroon, 33/303 [10.9%]; and Uganda, 27/137 [19.7%]).

STUDY DESIGN/RESULTS

Phylogenetic analysis of the S-gene sequences identified HBV genotypes E (HBV/E, n=96) and A (HBV/A, n=47) distributed as follows: 87% of HBV/E and 13% of HBV/A in Côte d'Ivoire; 100% of HBV/E in Ghana; 67% of HBV/E and 33% of HBV/A in Cameroon; and 100% of HBV/A in Uganda. The average and maximal nucleotide distances among HBV/E sequences were 1.9% and 6.4%, respectively, suggesting a greater genetic diversity for this genotype than previously reported (p<0.001). HBV/A strains were classified into subgenotypes HBV/A1, HBV/A2 and HBV/A3. In Uganda, 93% of HBV/A strains belonged to HBV/A1 whereas HBV/A3 was the only subgenotype of HBV/A found in Cameroon. In Côte d'Ivoire, HBV/A strains were classified as HBV/A1 (11.1%), HBV/A2 (33.3%) and HBV/A3 (55.6%). Phylogeographic analysis of the sequences available from Africa supported earlier suggestions on the origin of HBV/A1, HBV/A2 and HBV/A3 in East, South and West/Central Africa, respectively. Using predicted amino acid sequences, hepatitis B surface antigen (HBsAg) was classified into serotype ayw4 in 93% of HBV/E strains and adw2 in 68% of HBV/A strains. Also, 7.7% of the sequences carried substitutions in HBsAg associated with immune escape.

CONCLUSIONS

The observations of pan-African and global dissemination of HBV/A1 and HBV/A2, and the circulation of HBV/E and HBV/A3 almost exclusively in West and Central Africa suggest a more recent increase in prevalence in Africa of HBV/E and HBV/A3 compared to HBV/A1 and HBV/A2. The broad genetic heterogeneity of HBsAg detected here may impact the efficacy of prevention and control efforts in sub-Saharan Africa.

Hepatitis B virus in the Maghreb region: from epidemiology to prospective research

Hepatitis B virus (HBV) represents an important health problem in the Maghreb countries, Algeria, Libya, Mauritania, Morocco and Tunisia, but no detailed synthesis of its epidemiology is available. In this review, we systematically searched for data about HBV in the Maghreb in peer-reviewed databases and included in our analysis works written in English and French, as well as institutional reports and regional conference meeting abstracts. We estimated national and regional prevalence of chronic HBV infection. In addition, we discuss molecular features of the viral strains circulating in the region. Data analysis suggests that in the Maghreb region HBs antigen carriage concerns 1.8-4.9% of the population for an estimated number of 2.7 million persons. Genotype D, subtype D7, is predominant and mutations in the precore region of HBV genome are highly prevalent. This epidemiological situation requires obviously widespread active interventions for prevention and control. In addition, anti-hepatitis B vaccination programme should be applied with the utmost discipline in the five countries considered in this present review. This systematic review will, hopefully, increase knowledge at disposal of Public Health authorities, enabling better resource allocation and healthcare delivery. The present synthesis intends to stimulate policies aiming at preventing the spread of HBV, keeping in mind that eradication of the virus from Maghrebi populations should be the ultimate objective of Public Health authorities.

Co-infections with hepatitis B and C viruses in human immunodeficiency virus-infected patients in Morocco

Human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) are major public health concerns. We aimed to determine the prevalence of HBV and HCV infections among HIV-infected patients, and to identify the main circulating hepatitis strains in Morocco. The study was carried out in 503 HIV-infected patients. Our survey indicated that the prevalence of HIV/hepatitis co-infection was 10.6%; 5.2% of patients were HBV surface antigen positive, and 5.4% of patients were anti-HCV positive. Among the HBV surface antigen-positive group, HBV DNA sequencing identified exclusively genotype D (D1: 26.7%; D7: 73.3%) in accordance with what is found in the general population. In contrast, sequencing of HCV isolates produced an unusual subtype distribution with a decreasing order of prevalence: 1a, 3a (both 23.5%), 1b, 4a (both 17.6%), 1c (11.8%) and 6h (6%).

Hepatitis B virus in the Arab world: where do we stand?

The epidemiology of viral hepatitis is of great importance for planning and managing health provision for all the countries in the Arab world. However, data on viral hepatitis are not readily available in a large percentage of Arab countries. Hepatitis B virus (HBV) is considered to be one of the most important causes of chronic hepatitis, cirrhosis and hepatocellular carcinoma. A systematic electronic search of published literature was conducted to extract data on epidemiology and risk factors for the analysis of HBV infection among the countries in the Arab world. The prevalence of chronic HBV infection was found to be decreasing in some Arab countries although it was still unacceptably high. This was particularly evident in the Arabian Gulf region, in Lebanon, Egypt and Libya. The age-specific prevalence varied from country to country with decline in prevalence being noted among children in the Gulf States and among Libyan women. These declines in prevalence are most likely to be related to the Expanded Immunization Programme. The alarmingly high prevalence of chronically infected patients in some areas and the widespread differences in HBV prevalence between Arab nations may be explained by the variation in risk factors involved. This situation calls for targeted approaches to tackle HBV-related mortality and morbidity. Precise HBV infection prevalence data are needed at the national and the sub-national level to estimate the disease burden, guide health intervention programmes and evaluate vaccine efficiency.

Variability in the precore and core promoter regions of HBV strains in Morocco: characterization and impact on liver disease progression

Background

Hepatitis B virus (HBV) is one of the most common human pathogens that cause aggressive hepatitis and advanced liver disease (AdLD), including liver cirrhosis and Hepatocellular Carcinoma. The persistence of active HBV replication and liver damage after the loss of hepatitis B e antigen (HBeAg) has been frequently associated with mutations in the pre-core (pre-C) and core promoter (CP) regions of HBV genome that abolish or reduce HBeAg expression. The purpose of this study was to assess the prevalence of pre-C and CP mutations and their impact on the subsequent course of liver disease in Morocco.

Methods/Principal Findings

A cohort of 186 patients with HBeAg-negative chronic HBV infection was studied (81 inactive carriers, 69 with active chronic hepatitis, 36 with AdLD). Pre-C and CP mutations were analyzed by PCR-direct sequencing method. The pre-C stop codon G1896A mutation was the most frequent (83.9%) and was associated with a lower risk of AdLD development (OR, 0.4; 95% CI, 0.15–1.04; p = 0.04). HBV-DNA levels in patients with G1896A were not significantly different from the other patients carrying wild-type strains (p = 0.84). CP mutations C1653T, T1753V, A1762T/G1764A, and C1766T/T1768A were associated with higher HBV-DNA level and increased liver disease severity. Multiple logistic regression analysis showed that older age (≥40 years), male sex, high viral load (>4.3 log₁₀ IU/mL) and CP mutations C1653T, T1753V, A1762T/G1764A, and C1766T/T1768A were independent risk factors for AdLD development. Combination of these mutations was significantly associated with AdLD (OR, 7.52; 95% CI, 4.8–8; p<0.0001).

Conclusions

This study shows for the first time the association of HBV viral load and CP mutations with the severity of liver disease in Moroccan HBV chronic carriers. The examination of CP mutations alone or in combination could be helpful for prediction of the clinical outcome.

Tracking the naturally occurring mutations across the full-length genome of hepatitis B virus of genotype D in different phases of chronic e-antigen-negative infection

Hepatitis B e-antigen (HBeAg)-negative chronic HBV infection is highly prevalent in several parts of the world, including India, with the clinical spectrum ranging from inactive carrier (IC) state to chronic 'e-negative' hepatitis B (CHB) and culminating in advanced liver disease such as cirrhosis (LC). The present study has for the first time investigated the natural diversity of HBV belonging to genotype D in treatment-naïve Indian patients representing the above phases of HBeAg-negative infection to identify candidate mutations associated with each disease state. Studies of full-length HBV/D sequences revealed that the progressive accumulation and persistence of mutations in basal core promoter, negative regulatory element, Pre-core region, the B- and T-cell epitopes of X protein as well as deletions in the PreS region contribute significantly to disease progression from IC through CHB to LC. In addition, the development of CHB was associated with a significant increase in viral variants characterized by mutations in enhancer II, preS1 promoter, T-cell epitope of core and B-cell epitope region of PreS1. While few of the mutations were previously reported in the context of HBV genotypes B and C, others had not been documented before. Our results thus highlight a distinct pattern of mutation in HBV/D that may help in predicting clinical outcomes of HBeAg-negative infection and have implications for better clinical management of the patients.

Spatial and temporal dynamics of hepatitis B virus D genotype in Europe and the Mediterranean Basin

Hepatitis B virus genotype D can be found in many parts of the world and is the most prevalent strain in south-eastern Europe, the Mediterranean Basin, the Middle East, and the Indian sub-continent. The epidemiological history of the D genotype and its subgenotypes is still obscure because of the scarcity of appropriate studies. We retrieved from public databases a total of 312 gene P sequences of HBV genotype D isolated in various countries throughout the world, and reconstructed the spatio-temporal evolutionary dynamics of the HBV-D epidemic using a bayesian framework.The phylogeographical analysis showed that India had the highest posterior probability of being the location of the tree root, whereas central Asia was the most probable location of the common ancestor of subgenotypes D1-D3. HBV-D5 (identified in native Indian populations) diverged from the tree root earlier than D1-D3. The time of the most recent common ancestor (tMRCA) of the tree root was 128 years ago, which suggests that the common ancestor of the currently circulating subgenotypes existed in the second half of the XIX century. The mean tMRCA of subgenotypes D1-D3 was between the 1940s and the 1950-60s. On the basis of our phylogeographic reconstruction, it seems that HBV-D reached the Mediterranean area in the middle of the XX century by means of at least two routes: the first pathway (mainly due to the spread of subgenotype D1) crossing the Middle East and reaching north Africa and the eastern Mediterranean, and the second pathway (closely associated with D2) that crossed the former Soviet Union and reached eastern Europe and the Mediterranean through Albania. We hypothesise that the main route of dispersion of genotype D was the unsafe use of injections and drug addiction.