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1.
Article in English | MEDLINE | ID: mdl-38221914

ABSTRACT

Background: The relationship between viral infections and host factors holds high hopes for identifying the role of Interferon Lambda 3 (IFNL3) and Interleukin 6 (IL-6) polymorphisms in the development of Chronic Liver Disease (CLD) in patients infected with hepatitis Delta virus (HDV) in the Western Brazilian Amazon. Methods: Cross-sectional study conducted with a cohort of 40 chronic HDV patients, 27 with CLD and 13 without evident liver damage. Biological samples from the participants were analyzed using the polymerase chain reaction (PCR) technique, followed by sequencing by the automated Sanger method. Results: The rs8099917 T allele, from the IFNL3 gene, showed a higher frequency in both groups; however, it was not possible to establish an association with HDV infection [OR = 1.42 (0.42 - 4.75; p = 0.556 (95% CI). For IL-6, the rs1800795 G allele was superior to rs1800795 C. Analyzing both distributions in the studied groups, any association with HDV was absent (p > 0.05). Conclusion: The results suggest that the rs8099917 T/G (IFNL3) and rs1800795 G/C (IL-6) polymorphisms are not associated with the evolution of HDV in the studied population.

2.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;30: e20230025, 2024. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1528979

ABSTRACT

Background: The relationship between viral infections and host factors holds high hopes for identifying the role of Interferon Lambda 3 (IFNL3) and Interleukin 6 (IL-6) polymorphisms in the development of Chronic Liver Disease (CLD) in patients infected with hepatitis Delta virus (HDV) in the Western Brazilian Amazon. Methods: Cross-sectional study conducted with a cohort of 40 chronic HDV patients, 27 with CLD and 13 without evident liver damage. Biological samples from the participants were analyzed using the polymerase chain reaction (PCR) technique, followed by sequencing by the automated Sanger method. Results: The rs8099917 T allele, from the IFNL3 gene, showed a higher frequency in both groups; however, it was not possible to establish an association with HDV infection [OR = 1.42 (0.42 - 4.75; p = 0.556 (95% CI). For IL-6, the rs1800795 G allele was superior to rs1800795 C. Analyzing both distributions in the studied groups, any association with HDV was absent (p > 0.05). Conclusion: The results suggest that the rs8099917 T/G (IFNL3) and rs1800795 G/C (IL-6) polymorphisms are not associated with the evolution of HDV in the studied population.


Subject(s)
Humans , Hepatitis Delta Virus , Hepatitis D, Chronic , Polymorphism, Single Nucleotide , Brazil/epidemiology
3.
Braz J Infect Dis ; 26(5): 102700, 2022.
Article in English | MEDLINE | ID: mdl-36088957

ABSTRACT

Hepatitis B is considered an important public health problem worldwide because it is a chronic infection with a risk factor for cirrhosis and cellular hepatocellular carcinoma. In Brazil, the Rondônia State ranks first in the Northern region regarding the number of deaths due to hepatitis B. In the Amazon basin, genotype F is considered specific to the Americas identified in native populations. But few data on HBV genotyping and phylogenetic analysis are available. The objective of this study was to evaluate the genotypes and subgenotypes of the hepatitis B virus in indigenous people chronic carriers residing in cities of Guajará Mirim and Nova Mamoré in state of Rondônia/Brazil, on the border with Bolivia. A fragment of 417 bp (S gene) was amplified by PCR and submitted to nucleotide sequencing. The genotypes and subgenotypes of the HBV strains were determined through phylogenetic inference using genomic sequences from 197 representatives of the genotypes (A-H). Of the 41 chronic hepatitis B patients enrolled in this study, 27 were HBV-DNA positive. Of the 27 DNA-HBV positives, 39% (17/41) had individual HBV infection and 27% (10/41) were coinfected with HDV. The frequency of genotypes was 40.7% (11/27) for genotype D (HBV-D), 33.3% (9/27) for genotype F (HBV-F) and 25.9% (7/27) for genotype A (HBV-A) with circulating subgenotypes F2, F4, D2, D3, A1, and A2. We characterized the genotypes and subgenotypes of HBV circulating among in indigenous in the State of Rondônia shows for the first time the HBV/D genotype whit greater frequency circulating in nativos of state Rondônia. In conclusion, our findings showed a diversity of HBV genotypes, which is also found in other Brazilian geographical regions.


Subject(s)
Hepatitis B virus , Hepatitis B , Bolivia/epidemiology , Brazil/epidemiology , DNA, Viral/genetics , Genetic Variation/genetics , Genotype , Hepatitis B/epidemiology , Hepatitis B virus/genetics , Humans , Indigenous Peoples , Nucleotides , Phylogeny , Sequence Analysis, DNA
4.
Front Med (Lausanne) ; 9: 1069372, 2022.
Article in English | MEDLINE | ID: mdl-36816726

ABSTRACT

Introduction: Infection with hepatitis delta virus (HDV) is one of the most severe hepatitis B virus (HBV) complications, with a more rapid progression to cirrhosis and an increased risk of hepatic decompensation and death. Data on HDV infection in Cuba are limited. The aims of our study were to determine the HDV prevalence in HBsAg carriers and to characterize the HDV strains circulating. The data were used to assess the possibility of HDV elimination in the Cuban HBV epidemiological setting. Methods: Five hundred and two serum samples from the same number of HBsAg carriers collected in the period 2006-2019 from all over the country were tested for anti-HDV total antibodies. If positive, the samples were analyzed for HDV-RNA using Real-Time RT-PCR targeting the ribozyme and HD antigen domains followed by genotyping based on phylogenetic analysis. Results: Two samples were anti-HDV positive [0.39% (95% CI 0.11-1.44)]. One of them was also HDV-RNA positive. Clinically, the patient with active HDV infection had compensated liver cirrhosis. Phylogenetic analysis showed that the virus belonged to genotype 1 and thus clustered with contemporary strains from North America, Europe, Middle East, and Asia. Discussion: This is the first HDV study, including molecular detection and virus characterization, done after the introduction of the universal childhood anti-hepatitis B vaccination. The very low prevalence of HDV infection in HBsAg carriers combined with the high HBV vaccination coverage of all newborn children, of previously identified risk groups, and of the general population currently under 40 years of age suggests that HDV elimination is feasible in Cuba if the success in HBV control is maintained.

5.
Braz. j. infect. dis ; Braz. j. infect. dis;26(5): 102700, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1403886

ABSTRACT

Abstract Hepatitis B is considered an important public health problem worldwide because it is a chronic infection with a risk factor for cirrhosis and cellular hepatocellular carcinoma. In Brazil, the Rondônia State ranks first in the Northern region regarding the number of deaths due to hepatitis B. In the Amazon basin, genotype F is considered specific to the Americas identified in native populations. But few data on HBV genotyping and phylogenetic analysis are available. The objective of this study was to evaluate the genotypes and subgenotypes of the hepatitis B virus in indigenous people chronic carriers residing in cities of Guajará Mirim and Nova Mamoré in state of Rondônia/Brazil, on the border with Bolivia. A fragment of 417 bp (S gene) was amplified by PCR and submitted to nucleotide sequencing. The genotypes and subgenotypes of the HBV strains were determined through phylogenetic inference using genomic sequences from 197 representatives of the genotypes (A-H). Of the 41 chronic hepatitis B patients enrolled in this study, 27 were HBV-DNA positive. Of the 27 DNA-HBV positives, 39% (17/41) had individual HBV infection and 27% (10/41) were coinfected with HDV. The frequency of genotypes was 40.7% (11/27) for genotype D (HBV-D), 33.3% (9/27) for genotype F (HBV-F) and 25.9% (7/27) for genotype A (HBV-A) with circulating subgenotypes F2, F4, D2, D3, A1, and A2. We characterized the genotypes and subgenotypes of HBV circulating among in indigenous in the State of Rondônia shows for the first time the HBV/D genotype whit greater frequency circulating in nativos of state Rondônia. In conclusion, our findings showed a diversity of HBV genotypes, which is also found in other Brazilian geographical regions.

6.
Hepatología ; 1(2): 116-133, 2020. ilus, tab
Article in Spanish | LILACS, COLNAL | ID: biblio-1396635

ABSTRACT

El virus de la hepatitis delta (VHD) es un virus satélite del virus de la hepatitis B (VHB), dado que requiere el antígeno de superficie del VHB (HBsAg) para la producción de partículas virales infecciosas. Se han caracterizado ocho genotipos del VHD, con una distribución geográfica relacionada con la prevalencia de la infección por VHB. Se estima que aproximadamente el 5% de los pacientes con infección crónica por VHB también están infectados con VHD. Se han descrito dos tipos de infección: la coinfección simultánea por VHB y VHD, y la superinfección con VHD en un paciente previamente infectado por VHB, esta última asociada a una mayor morbilidad y mortalidad por falla hepática aguda. La infección se diagnostica en nuestro medio con la determinación de IgM contra el VHD, acompañada idealmente de la carga viral. Aunque el tratamiento de elección es la terapia con interferón alfa pegilado, en el momento se están evaluando otros medicamentos antivirales en ensayos clínicos, con resultados alentadores, teniendo en cuenta el efecto observado en la carga viral del VHD y/o del VHB en los pacientes. La presente revisión tiene como objetivo incluir temas como la biología del virus, la epidemiología, las características clínicas, el diagnóstico y el tratamiento en la infección por VHD.


Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus (HBV), as it requires the HBV surface antigen (HBsAg) for the production of infectious viral particles. Eight HDV genotypes have been characterized with a geographic distribution associated with the prevalence of HBV infection. It is estimated that approximately 5% of patients with chronic HBV infection are also infected with HDV. Two types of infection have been described: coinfection, by simultaneously contracting HBV and HDV infection, and superinfection, by contracting HDV when chronically infected with HBV, the latter associated with increased morbidity and mortality from acute liver failure. Anti-HDV IgM is used to diagnose the infection, ideally together with the detection of HDV-RNA. Although the treatment of choice is pegylated interferon alpha, other antiviral drugs are currently being evaluated in clinical trials, with encouraging results, in terms of their effect on HDV and/or HBV viral load in patients. This review aims to include topics such as virus biology, epidemiology, clinical manifestations, diagnosis, and treatment in HDV infection.


Subject(s)
Humans , Hepatitis Delta Virus , Hepatitis B virus , Epidemiology , Diagnosis , Drug Therapy
7.
Viruses ; 11(11)2019 10 29.
Article in English | MEDLINE | ID: mdl-31671829

ABSTRACT

The hepatitis delta virus (HDV) is a globally distributed agent, and its genetic variability allows for it to be organized into eight genotypes with different geographic distributions. In South America, genotype 3 (HDV-3) is frequently isolated and responsible for the most severe form of infection. The objective of this study was to evaluate the evolutionary and epidemiological dynamics of HDV-3 over the years and to describe its distribution throughout this continent in an evolutionary perspective. While using Bayesian analysis, with strains being deposited in the Nucleotide database, the most recent common ancestor was dated back to 1964 and phylogenetic analysis indicated that the dispersion may have started in Brazil, spreading to Venezuela and then to Colombia, respectively. Exponential growth in the effective number of infections was observed between the 1950s and 1970s, years after the first report of the presence of HDV on the continent, during the Labrea Black Fever outbreak, which showed that the virus continued to spread, increasing the number of cases decades after the first reports. Subsequently, the analysis showed a decrease in the epidemiological levels of HDV, which was probably due to the implantation of the vaccine against its helper virus, hepatitis B virus, and serological screening methods implemented in the blood banks.


Subject(s)
Hepatitis D/virology , Hepatitis Delta Virus/classification , Hepatitis Delta Virus/genetics , Bayes Theorem , Evolution, Molecular , Genetic Variation , Genotype , Hepatitis D/epidemiology , Hepatitis D/transmission , Hepatitis Delta Virus/isolation & purification , Hepatitis delta Antigens/genetics , Humans , Phylogeny , Phylogeography , RNA, Viral/genetics , South America/epidemiology
8.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;52: e20180289, 2019. tab, graf
Article in English | LILACS | ID: biblio-985161

ABSTRACT

Abstract Hepatitis delta virus (HDV) has been associated with acute or chronic hepatitis in Latin America, but there is no prevalence study covering South American countries. This meta-analysis aimed to estimate anti-HDV prevalence through a systematic review of published articles in English, Portuguese and Spanish until December 2017. Searches were conducted in Health Virtual Library, Capes, Lilacs, PubMed, and SciELO, according to defined criteria regarding participant selection and geographical setting. Study quality was assessed using the GRADE guidelines. Pooled anti-HDV prevalence was calculated using the DerSimonian-Laird random-effects model with Freeman-Tukey double arcsine transformation. Out of the 405 identified articles, only 31 met the eligibility criteria for inclusion in the meta-analysis. In South America, pooled anti-HDV prevalence among hepatitis B virus carriers was 22.37% (95% confidence interval: 13.72-32.26), though it appeared less frequently in some countries and populations, according to the data collection date. The findings indicated significant successive reductions in anti-HDV prevalence over thirty years. However, there was a scarcity of HDV epidemiological studies outside the Amazon Basin, notably in the Southwest continent and absence of target population standardization. There was a high HDV prevalence in South American countries, despite differences in methodological characteristics and outcomes, highlighting a drastic decline in the last decades. Future studies should identify HDV prevalence estimates in other regions of the continent and identify risk factors.


Subject(s)
Humans , Hepatitis D/epidemiology , Hepatitis Delta Virus/genetics , Hepatitis Delta Virus/immunology , Phylogeny , South America/epidemiology , Prevalence , Genotype
9.
Arq. gastroenterol ; Arq. gastroenterol;55(1): 14-17, Apr.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-888243

ABSTRACT

ABSTRACT BACKGROUND: The Amazon region is one of the main endemic areas of hepatitis delta in the world and the only one related to the presence of genotype 3 of the delta virus. OBJECTIVE: To analyze the profile, mortality and survival of cirrhotic patients submitted to liver transplantation for chronic hepatitis delta virus and compare with those transplanted by hepatitis B virus monoinfection. METHODS: Retrospective, observational and descriptive study. From May 2002 to December 2011, 629 liver transplants were performed at the Walter Cantídio University Hospital, of which 29 patients were transplanted due to cirrhosis caused by chronic delta virus infection and 40 by hepatitis B chronic monoinfection. The variables analyzed were: age, sex, MELD score, Child-Pugh score, upper gastrointestinal bleeding and hepatocellular carcinoma occurrence before the transplantation, perioperative platelet count, mortality and survival. RESULTS: The Delta Group was younger and all came from the Brazilian Amazon Region. Group B presented a higher proportion of male patients (92.5%) compared to Group D (58.6%). The occurrence of upper gastrointestinal bleeding before transplantation, MELD score, and Child-Pugh score did not show statistical differences between groups. The occurrence of hepatocellular carcinoma and mortality were higher in the hepatitis B Group. The survival in 4 years was 95% in the Delta Group and 75% in the B Group, with a statistically significant difference (P=0.034). Patients with hepatitis delta presented more evident thrombocytopenia in the pre-transplantation and in the immediate postoperative period. CONCLUSION: The hepatitis by delta virus patients who underwent liver transplantation were predominantly male, coming from the Brazilian Amazon region and with similar liver function to the hepatitis B virus patients. They had a lower incidence of hepatocellular carcinoma, more marked perioperative thrombocytopenia levels and frequent episodes of upper gastrointestinal bleeding. Patients with hepatitis by delta virus had lower mortality and higher survival than patients with hepatitis B virus.


RESUMO CONTEXTO: A região Amazônica é uma das principais áreas endêmicas da hepatite delta no mundo e a única relacionada com a presença do genótipo 3 do vírus delta. OBJETIVO: Analisar o perfil, mortalidade e sobrevida dos pacientes cirróticos submetidos a transplante hepático por hepatite crônica pelo vírus delta e comparar com os transplantados pela monoinfecção do vírus da hepatite B. MÉTODOS: Estudo retrospectivo, observacional e descritivo. Entre maio de 2002 a dezembro de 2011, foram realizados 629 transplantes de fígado no Hospital Universitário Walter Cantídio, dos quais 29 pacientes foram transplantados por cirrose causada pela infecção crônica do vírus delta e 40 pela monoinfecção crônica da hepatite B. As variáveis analisadas foram: origem, idade, sexo, escore de MELD, classificação de Child-Pugh, ocorrência de hemorragia digestiva alta e carcinoma hepatocelular antes do transplante, número de plaquetas perioperatória, mortalidade e sobrevida. RESULTADOS: O Grupo Delta foi mais jovem e todos oriundos da região Amazônica Brasileira. O Grupo B apresentou maior proporção de pacientes do sexo masculino (92,5%) em relação ao Grupo D (58,6%). A ocorrência de hemorragia digestiva alta antes do transplante, escore de MELD e classificação de Child-Pugh não obtiveram diferenças estatísticas entre os grupos. A ocorrência de carcinoma hepatocelular e a mortalidade foram maiores no grupo com hepatite B. A sobrevida em 4 anos foi de 95% no Grupo delta e 75% no Grupo B com diferença estatisticamente significante (P=0,034). Pacientes com hepatite delta, apresentaram mais acentuada plaquetopenia no pré-transplante e no pós-operatório imediato. CONCLUSÃO: Os pacientes com hepatite por vírus delta submetidos ao transplante hepático eram predominantemente homens, vindos da região da Amazônia brasileira e com função hepática semelhante a dos pacientes com vírus da hepatite B. Apresentavam menor incidência de carcinoma hepatocelular, níveis de trombocitopenia perioperatória mais acentuados e episódios frequentes de hemorragia digestiva alta. Os pacientes com hepatite por vírus delta apresentaram menor mortalidade e maior sobrevida que os pacientes com vírus da hepatite B.


Subject(s)
Humans , Male , Female , Adult , Liver Transplantation/mortality , Hepatitis B, Chronic/mortality , Hepatitis D, Chronic/mortality , Liver Cirrhosis/mortality , Blood Platelets/chemistry , Brazil/epidemiology , Hepatitis Delta Virus/genetics , Retrospective Studies , Liver Transplantation/statistics & numerical data , Sex Distribution , Carcinoma, Hepatocellular/mortality , Hepatitis B, Chronic/complications , Hepatitis D, Chronic/surgery , Hepatitis D, Chronic/complications , Kaplan-Meier Estimate , Liver Cirrhosis/surgery , Liver Cirrhosis/virology , Liver Neoplasms/mortality , Middle Aged
10.
J Viral Hepat ; 25(7): 860-869, 2018 07.
Article in English | MEDLINE | ID: mdl-29406571

ABSTRACT

In association with hepatitis B virus (HBV), hepatitis delta virus (HDV) is a subviral agent that may promote severe acute and chronic forms of liver disease. Based on the percentage of nucleotide identity of the genome, HDV was initially classified into three genotypes. However, since 2006, the original classification has been further expanded into eight clades/genotypes. The intergenotype divergence may be as high as 35%-40% over the entire RNA genome, whereas sequence heterogeneity among the isolates of a given genotype is <20%; furthermore, HDV recombinants have been clearly demonstrated. The genetic diversity of HDV is related to the geographic origin of the isolates. This study shows the first comprehensive bioinformatic analysis of the complete available set of HDV sequences, using both nucleotide and protein phylogenies (based on an evolutionary model selection, gamma distribution estimation, tree inference and phylogenetic distance estimation), protein composition analysis and comparison (based on the presence of invariant residues, molecular signatures, amino acid frequencies and mono- and di-amino acid compositional distances), as well as amino acid changes in sequence evolution. Taking into account the congruent and consistent results of both nucleotide and amino acid analyses of GenBank available sequences (recorded as of January, 2017), we propose that the eight hepatitis D virus genotypes may be grouped into three large genogroups fully supported by their shared characteristics.


Subject(s)
Computational Biology , Genome, Viral , Hepatitis Delta Virus/genetics , Sequence Analysis, DNA , Genetic Variation , Genotype , Hepatitis Delta Virus/classification , Phylogeny , Recombination, Genetic , Sequence Homology, Amino Acid , Sequence Homology, Nucleic Acid
11.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;50(3): 423-426, May-June 2017. graf
Article in English | LILACS | ID: biblio-896983

ABSTRACT

Abstract Acquired hepatocerebral degeneration is a neurological syndrome with typical clinical (extrapyramidal and neuropsychiatric) symptoms and brain magnetic resonance imaging findings (high T1 signal in the globus pallidus). It occurs mainly in patients with advanced liver disease, such as in patients co-infected with hepatitis B virus (HBV) and hepatitis delta virus (HDV). However, there are no reports relating HBV/HDV coinfection and acquired hepatocerebral degeneration. This report presents the case of a 49-year-old woman with characteristics of acquired hepatocerebral degeneration and liver cirrhosis due to HBV/HDV coinfection, and presents the main theories of the physiopathology of this condition.


Subject(s)
Humans , Female , Hepatitis D/complications , Hepatitis B/complications , Hepatolenticular Degeneration/virology , Liver Cirrhosis/virology , Coinfection/virology , Middle Aged
12.
BMC Infect Dis ; 16(1): 525, 2016 Sep 29.
Article in English | MEDLINE | ID: mdl-27686363

ABSTRACT

BACKGROUND: The Hepatitis Delta Virus (HDV) can increase the incidence of fulminant hepatitis. For this infection occurs, the host must also be infected with Hepatitis B Virus. Previous studies demonstrated the endemicity and near exclusivity of this infection in the Amazon region, and as a consequence of the difficulty in accessing this area we used dried blood spots (DBS) in sample collection. The aims of this study were to investigate the presence of recombination, to analyze the epidemiology, ancestry and evolutionary pressures on HDV in Brazil. METHODS: Blood samples from 50 individuals were collected using dried-blood spots (DBS 903, Whatman), and sent via regular mail to Retrovirology Laboratory from Federal University of São Paulo, where the samples were processed. In the analysis the following software were used: PhyML, RDP, BEAST, jModelTest and CODEML. RESULTS: Our results confirm the prevalence of HDV-3 in the Amazon region of Brazil, with the absence of inter-genotypic recombination. It was identified a positive selection in probable epitopes of HDV on B lymphocytes that might indicate that the virus is changing to escape the humoral response of the host. The analysis of the time of the most common ancestor demonstrated the exponential growth of this virus in late 1970s that lasted until 1995, after which it remained constant. It was also observed a probable founder effect in two cities, which demonstrate the need to focus on prevention methods against HBV/HDV infection. CONCLUSION: We confirmed the prevalence of HDV-3 in the Amazon region of Brazil, without inter-genotypic recombination. The analysis of the time of the most common ancestor showed that this infection remain constant in the studied area. Taking into account the probable founder effect established in the cities of Rio Branco and Porto Velho, a focus on preventive methods is recommended against these infections.

13.
J Virol Methods ; 197: 19-24, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24316446

ABSTRACT

The hepatitis delta virus (HDV) is a pathogen that causes a severe and rapidly progressive disease of hepatocytes. The measurement of viral load in the peripheral blood of patients with HDV infections is important for diagnosis, treatment monitoring, and support for follow-up studies of viral replication during the course of the disease. This study reports the development of an assay capable of detecting and quantifying the abundance of HDV particles in serum samples, based on reverse-transcription quantitative PCR (RT-qPCR). Two standards for calibration were produced for determining the viral load of HDV: a cDNA cloned into a linear plasmid and a transcribed RNA. For validating this assay, 140 clinical samples of sera were used, comprising 100 samples from patients who tested positive for anti-HDV and hepatitis B virus surface antigen (HBsAg) by ELISA; 30 samples from blood donors; 5 samples monoinfected with hepatitis B virus (HBV); and 5 samples monoinfected with hepatitis C virus (HCV). The HDV RT-qPCR assay performed better when calibrated using the standard based on HDV cDNA cloned into a linear plasmid, yielding an efficiency of 99.8% and a specificity of 100% in the in vitro assays. This study represents the first HDV RT-qPCR assay developed with clinical samples from Brazil and offers great potential for new clinical efficacy studies of antiviral therapeutics for use in patients with hepatitis delta in the western Amazon region.


Subject(s)
Hepatitis D/diagnosis , Hepatitis Delta Virus/isolation & purification , Molecular Diagnostic Techniques/methods , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Viral Load/methods , Brazil , Hepatitis D/virology , Hepatitis Delta Virus/genetics , Humans
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