Reconstruction of the spatial and temporal dynamics of hepatitis B virus genotype D in the Americas.

Hepatitis B virus (HBV) genotype D (HBV/D) is globally widespread, and ten subgenotypes (D1 to D10) showing distinct geographic distributions have been described to date. The evolutionary history of HBV/D and its subgenotypes, for which few complete genome sequences are available, in the Americas is not well understood. The main objective of the current study was to determine the full-length genomic sequences of HBV/D isolates from Brazil and frequency, origin and spread of HBV/D subgenotypes in the Americas. Complete HBV/D genomes isolated from 39 Brazilian patients infected with subgenotypes D1 (n = 1), D2 (n = 10), D3 (n = 27), and D4 (n = 1) were sequenced and analyzed together with reference sequences using the Bayesian coalescent and phylogeographic framework. A search for HBV/D sequences available in GenBank revealed 209 complete and 926 partial genomes from American countries (Argentina, Brazil, Canada, Chile, Colombia, Cuba, Haiti, Martinique, Mexico, USA and Venezuela), with the major circulating subgenotypes identified as D1 (26%), D2 (17%), D3 (36%), D4 (21%), and D7 (1%) within the continent. The detailed evolutionary history of HBV/D in the Americas was investigated by using different evolutionary time scales. Spatiotemporal reconstruction analyses using short-term substitution rates suggested times of the most recent common ancestor for the American HBV/D subgenotypes coincident with mass migratory movements to Americas during the 19th and 20th centuries. In particular, significant linkages between Argentina and Syria (D1), Brazil and Central/Eastern Europe (D2), USA and India (D2), and Brazil and Southern Europe (D3) were estimated, consistent with historical and epidemiological data.

Hepatitis B virus genotypes A1, A2 and E in Cape Verde: Unequal distribution through the islands and association with human flows.

Hepatitis B virus (HBV) diversity has not been previously studied in Cape Verde. The archipelago was discovered in 1460 by Portuguese explorers, who brought African slaves to colonise the islands. In this study, we investigated the HBV characteristics from 183 HBsAg-positive Cape Verdean individuals. Phylogenetic analysis of the pre-S/S region and the full-length genomes revealed 54 isolates with HBV/A1 (57%), 21 with HBV/A2 (22%), 19 with HBV/E (20%), and one with HBV/D (1%). HBV genotypes and subgenotypes were unequally distributed through the islands. In São Vicente, the main northern island, most isolates (84%) belonged to the African-originated HBV/A1, with the remaining isolates belonging to HBV/A2, which is prevalent in Europe. Interestingly, the HBV/A1 isolates from São Vicente were closely related to Brazilian sequences into the Asian-American clade, which suggests the dissemination of common African ancestors through slave trade. In contrast, in Santiago and nearby southern islands, where a recent influx from different populations circulates, a higher diversity of HBV was observed: HBV/A1 (40%); HBV/E (32%); HBV/A2 (28%); and HBV/D (1%). HBV/E is a recent genotype disseminated in Africa that was absent in the era of the slave trade. African and European human flows at different times of the history may explain the HBV diversity in Cape Verde. The possible origin and specifics of each HBV genotype circulating in Cape Verde are discussed.

Complete genome sequence of a hepatitis B virus isolate of genotype D2, subtype adrq+, from Brazil.

Hepatitis B virus (HBV) has been classified into 10 distinct serological subtypes of the surface antigen (HBsAg) that can be predicted by sequencing of the corresponding S gene. HBV genotype D usually displays determinants of subtypes ayw2 or ayw3. On the other hand, subtype adrq+ has been found exclusively in association with genotype C. Here, we describe the first HBV genome (isolate BR32) belonging to genotype D with the serological subtype adrq+. This isolate had a genome length of 3,062 nucleotides (nt), and no recombination events were observed in the BR32 genome that could explain the occurrence of the subtype adr in a genotype D isolate. Analysis of the quasispecies population revealed that 28 out of 30 clones (93%) were of subtype adrq+, while the subtypes of the two remaining could not be determined, since they contained an S residue (instead of K or R) at position 122 of HBsAg. These results will contribute to further epidemiological and evolutionary studies of HBV.

Serological and molecular evidence of hepadnavirus infection in swine.

INTRODUCTION AND OBJECTIVE: Recently, investigations in a swine herd identified evidence of the existence of a novel member of the Hepadnavirus family endemic in swine. The aim of this study was to investigate the serological and molecular markers of Hepadnavirus circulation in Brazilian domestic swine and wild boar herds, and to evaluate the identity with HBV and other Hepadnaviruses reported previously. MATERIALS AND METHODS: For the study, 376 swine were screened for hepatitis B virus serological markers. Analyses were performed in serum samples using commercial enzyme-linked immunosorbent assay (ELISA) kits (DiaSorin®) for anti-HBc, HBsAg and anti-HBs. Reactive and undetermined swine serum samples were selected to perform DNA viral extraction (QIAamp DNA Mini Kit, Qiagen®), partial genome amplification and genome sequencing. RESULTS: From 376 swine samples analysed, 28 (7.45%) were reactive to anti-HBc, 3 (0.80%) to HBsAg and 6 (1.6%) to anti-HBs. Besides, more 17 (4.52%) swine samples analyzed were classified in the grey zone of the EIA test to anti-HBc and 2 (0.53%) to HBsAg. From 49 samples molecularly analyzed after serological trial, 4 samples showed a positive result for the qualitative PCR for Hepadnavirus. Phylogenetic reconstruction using partial genome sequencing (360 bp) of 3 samples showed similarity with HBV with 90.8-96.3% of identity. CONCLUSIONS: Serological and molecular data showed evidence of the circulation of a virus similar to hepatitis B virus in swine.

Hepatitis B virus subgenotype A1: evolutionary relationships between Brazilian, African and Asian isolates.

Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

HIV-1, HBV, HCV, HTLV, HPV-16/18, and Treponema pallidum infections in a sample of Brazilian men who have sex with men.

BACKGROUND: Men who have sex with men (MSM) are more vulnerable to blood-borne infections and/or sexually-transmitted infections (STI). This study was conducted to estimate the prevalences of mono and co-infections of HIV-1 and other blood-borne/STIs in a sample of MSM in Campinas, Brazil. METHODS: Responding Driven Sampling (RDS) was used for recruitment of MSM. Serum samples collected from 558 MSM were analyzed for the presence of serological markers for HIV-1, HBV, HCV, HTLV, HPV-16/18, and T. pallidum infections. RESULTS: The highest prevalences of infection in serum samples were found for HPV-16 and 18 (31.9% and 20.3%, respectively). Approximately 8% of the study population showed infection with HIV-1, and within that group, 27.5% had recently become infected with HIV-1. HBV infection and syphilis were detected in 11.4% and 10% of the study population, respectively, and the rates of HTLV and HCV infection were 1.5% and 1%, respectively. With the exception of HTLV, all other studied infections were usually found as co-infections rather then mono-infections. The rates of co-infection for HCV, HPV-18, and HIV-1 were the highest among the studied infections (100%, 83%, and 85%, respectively). Interestingly, HTLV infection was usually found as a mono-infection in the study group, whereas HCV was found only as a co-infection. CONCLUSIONS: The present findings highlight the need to educate the MSM population concerning their risk for STIs infections and methods of prevention. Campaigns to encourage vaccination against HBV and HPV could decrease the rates of these infections in MSM.

Analysis of complete nucleotide sequences of Angolan hepatitis B virus isolates reveals the existence of a separate lineage within genotype E.

Hepatitis B virus genotype E (HBV/E) is highly prevalent in Western Africa. In this work, 30 HBV/E isolates from HBsAg positive Angolans (staff and visitors of a private hospital in Luanda) were genetically characterized: 16 of them were completely sequenced and the pre-S/S sequences of the remaining 14 were determined. A high proportion (12/30, 40%) of subjects tested positive for both HBsAg and anti-HBs markers. Deduced amino acid sequences revealed the existence of specific substitutions and deletions in the B- and T-cell epitopes of the surface antigen (pre-S1- and pre-S2 regions) of the virus isolates derived from 8/12 individuals with concurrent HBsAg/anti-HBs. Phylogenetic analysis performed with 231 HBV/E full-length sequences, including 16 from this study, showed that all isolates from Angola, Namibia and the Democratic Republic of Congo (n = 28) clustered in a separate lineage, divergent from the HBV/E isolates from nine other African countries, namely Cameroon, Central African Republic, Côte d'Ivoire, Ghana, Guinea, Madagascar, Niger, Nigeria and Sudan, with a Bayesian posterior probability of 1. Five specific mutations, namely small S protein T57I, polymerase Q177H, G245W and M612L, and X protein V30L, were observed in 79-96% of the isolates of the separate lineage, compared to a frequency of 0-12% among the other HBV/E African isolates.

Improved rolling circle amplification (RCA) of hepatitis B virus (HBV) relaxed-circular serum DNA (RC-DNA).

For functional analysis of HBV isolates, epidemiological studies and correct identification of recombinant genomes, the amplification of complete genomes is necessary. A method for completely in vitro amplification of full-length HBV genomes starting from serum RC-DNA is described. This uses in vitro completion/ligation of plus-strand HBV RC-DNA and amplification using Rolling-Circle Amplification, eventually followed by a genomic PCR. The method can amplify complete HBV genomes from sera with viral loads ranging from >1.0E+8 IU/ml down to 1.0E+3 IU/ml. The method can be applied to archived sera that have undergone long-term storage or to archived DNA serum extracts. The genomes can easily be cloned. HBV genotypes A-G can all be amplified with no apparent problems. A recombinant subgenotype A3/genotype E genome was identified and fully sequenced.

Phylogeography and evolutionary history of hepatitis B virus genotype F in Brazil.

BACKGROUND: Hepatitis B virus (HBV) genotype F (HBV/F) is considered to be indigenous to the Americas, but its emergence and spread in the continent remain unknown. Previously, only two HBV/F complete genome sequences from Brazil were available, limiting the contribution of Brazilian isolates to the phylogenetic studies of HBV/F. The present study was carried out to assess the proportion and geographic distributions of HBV/F subgenotypes in Brazil, to determine the full-length genomic sequences of HBV/F isolates from different Brazilian geographic regions, and to investigate the detailed evolutionary history and phylogeography of HBV/F in Brazil. METHODS: Complete HBV/F genomes isolated from 12 Brazilian patients, representing the HBV/F subgenotypes circulating in Brazil, were sequenced and analyzed together with sequences retrieved from GenBank, using the Bayesian coalescent and phylogeographic framework. RESULTS: Phylogenetic analysis using all Brazilian HBV/F S-gene sequences available in GenBank showed that HBV/F2a is found at higher frequencies countrywide and corresponds to all sequences isolated in the Brazilian Amazon Basin. In addition, the evolutionary analysis using complete genome sequences estimated an older median ancestral age for the Brazilian HBV/F2a compared to the Brazilian HBV/F1b and HBV/F4 subgenotypes, suggesting that HBV/F2a represents the original native HBV of Brazil. The phylogeographic patterns suggested a north-to-south flow of HBV/F2a from Venezuela to Brazil, whereas HBV/F1b and HBV/F4 strains appeared to have spread from Argentina to Brazil. CONCLUSIONS: This study suggests a plausible route of introduction of HBV/F subgenotypes in Brazil and demonstrates the usefulness of recently developed computational tools for investigating the evolutionary history of HBV.

Identification of novel recombinants of hepatitis B virus genotypes F and G in human immunodeficiency virus-positive patients from Argentina and Brazil.

Hepatitis B virus (HBV) genotype G (HBV/G) infection is almost always detected along with a co-infecting HBV strain that can supply HBeAg, typically HBV/A2. In this study we describe, in two human immunodeficiency virus (HIV)-positive patients from Argentina and Brazil, the first report of HBV/G infection in Argentina and co-circulation of HBV/G, HBV/F and G/F recombinants in the American continent. HBV isolates carrying the 36 bp insertion of HBV/G were the most prevalent in both patients, with >99 % of colonies hybridizing to a probe specific for this insertion. Phylogenetic analyses of full-length genomes and precore/core fragments revealed that F4 and F1b were the co-infecting subgenotypes in the Brazilian and Argentinian patients, respectively. Bootscanning analysis provided evidence of recombination in several clones from both patients, with recombination breakpoints located mainly at the precore/core region. These data should encourage further investigations on the clinical implications of HBV/G recombinants in HBV/HIV co-infected patients.

Detection of mixed populations of wild-type and YMDD hepatitis B variants by pyrosequencing in acutely and chronically infected patients.

BACKGROUND: Lamivudine (LAM) is associated with the highest known rate of resistance mutations among nucleotide analogs used to treat chronic hepatitis B virus (HBV) infection. Despite this, LAM continues in widespread use, especially in combination therapies. The primary LAM resistance mutation (rtM204V/I) occurs in the YMDD motif of HBV polymerase. The aim of this study was to characterize Brazilian HBV isolates from acute and chronic cases by direct sequencing, and to identify HBV quasispecies in the YMDD motif using a pyrosequencing method capable of detecting single-nucleotide polymorphisms. HBV DNA from serum samples of 20 individuals with acute HBV infection and 44 with chronic infection undergoing antiviral therapies containing LAM were analyzed by direct sequencing and pyrosequencing methods. RESULTS: Phylogenic analyses of direct-sequenced isolates showed the expected genotypes (A, D and F) for the Brazilian population in both acute and chronic infections. However, within genotype A isolates, subgenotype A2 was more frequently detected in acute cases than in chronic cases (P = 0.012). As expected, none of the individuals with acute hepatitis B had LAM-resistant isolates as a dominant virus population, whether detected by direct sequencing or pyrosequencing. However, pyrosequencing analyses showed that 45% of isolates (9/20) had minor subpopulations (4-17%) of LAM-resistant isolates. Among chronic patients undergoing LAM treatment, YMDD mutants were frequently found as a dominant virus population. In cases where wild-type virus was the dominant population, subpopulations of YMDD variants were usually found, demonstrating the complexity of HBV quasispecies. CONCLUSIONS: YMDD variants were frequently detected as a minor population in acute HBV infection. The occurrence of pre-existing variants may lead to a high frequency of resistant mutants during antiviral therapy in the chronic phase. In chronic infection, detection of YMDD variants before virological or biochemical breakthrough might contribute to making better therapy choices and thus improving treatment outcome.

Probable corticosteroid-induced reactivation of latent hepatitis B virus infection in an HIV-positive patient involving immune escape.

We describe a patient infected with human immunodeficiency virus who possessed a serological profile suggesting a previous cleared acute hepatitis B virus (HBV) infection, including high levels of antibodies against HBV surface antigen (anti-HBs). Following the administration of inhaled glucocorticosteroids combined with protease inhibitor-based antiretroviral treatment, the patient developed an unexpected severe acute hepatitis despite persistence of anti-HBs. A genotype A2 strain emerged with 2 major mutations in the S gene, sK122R and sD144E. Molecular and biological analyses strongly suggested reactivation of a latent HBV infection. The importance and the molecular basis of these 2 epitopes in immune-escape mechanisms and host-virus interactions are discussed.

Expression of Hepatitis B Virus Surface Antigen Containing Y100C Variant Frequently Detected in Occult HBV Infection.

Small hepatitis B virus surface protein (S-HBsAg) variant Y100C has been associated with HBsAg-negative phenotype. To determine whether Y100C substitution yields impaired HBsAg or small amounts of HBsAg that may reduce HBsAg detection by commercial anti-HBsAg antibodies, two eukaryotic expression plasmids, one containing a wild-type S and the other an S gene from a Y100C variant, were constructed and their levels of HBsAg compared by ELISA after transfection of HuH7 cells. Unexpectedly, the extracellular HBsAg levels detected with Y100C plasmid were higher than those observed with the wild-type plasmid, but without statistical significance. We concluded that the Y100C substitution alone did not play a role in reducing HBsAg amounts or HBsAg affinity by commercial ELISA assay. Further studies on in vitro replication fitness with the complete genome of HBV isolates displaying or not Y100C substitution may elucidate whether this mutation affects HBV replication and consequently HBsAg production.

Epidemiology and molecular characterization of hepatitis B virus in Luanda, Angola

An estimated 360 million people are infected with hepatitis B virus (HBV) worldwide. Among these, 65 million live in Africa. Despite the high levels of hepatitis B in Africa, HBV epidemiology is still poorly documented in most African countries. In this work, the epidemiological and molecular characteristics of HBV infection were evaluated among the staff, visitors and adult patients (n = 508) of a public hospital in Luanda, Angola. The overall prevalence of hepatitis B core antibody (anti-HBc) and hepatitis B surface antigen was 79.7 percent and 15.1 percent, respectively. HBV infection was higher in males and was more prevalent in individuals younger than 50 years old. HBV-DNA was detected in 100 percent of HBV "e" antigen-positive serum samples and in 49 percent of anti-hepatitis Be antibody-positive samples. Thirty-five out of the 40 HBV genotypes belonged to genotype E. Circulation of genotypes A (4 samples) and D (1 sample) was also observed. The present study demonstrates that HBV infection is endemic in Luanda, which has a predominance of genotype E. This genotype is only sporadically found outside of Africa and is thought to have emerged in Africa at a time when the trans-Atlantic slave trade had stopped.

Epidemiology and molecular characterization of hepatitis B virus in Luanda, Angola.

An estimated 360 million people are infected with hepatitis B virus (HBV) worldwide. Among these, 65 million live in Africa. Despite the high levels of hepatitis B in Africa, HBV epidemiology is still poorly documented in most African countries. In this work, the epidemiological and molecular characteristics of HBV infection were evaluated among the staff, visitors and adult patients (n = 508) of a public hospital in Luanda, Angola. The overall prevalence of hepatitis B core antibody (anti-HBc) and hepatitis B surface antigen was 79.7% and 15.1%, respectively. HBV infection was higher in males and was more prevalent in individuals younger than 50 years old. HBV-DNA was detected in 100% of HBV "e" antigen-positive serum samples and in 49% of anti-hepatitis Be antibody-positive samples. Thirty-five out of the 40 HBV genotypes belonged to genotype E. Circulation of genotypes A (4 samples) and D (1 sample) was also observed. The present study demonstrates that HBV infection is endemic in Luanda, which has a predominance of genotype E. This genotype is only sporadically found outside of Africa and is thought to have emerged in Africa at a time when the trans-Atlantic slave trade had stopped.

Occult hepatitis B virus infection and lamivudine-resistant mutations in isolates from renal patients undergoing hemodialysis.

BACKGROUND AND AIMS: Patients undergoing hemodialysis are at risk of infection with both hepatitis B virus (HBV) and hepatitis C virus (HCV). Occult HBV infection is usually associated with low levels of HBV and is frequently detected in HCV-infected patients. The aims of the present study were to compare the prevalence of occult HBV infection among anti-HCV-positive and anti-HCV-negative patients undergoing hemodialysis, and characterize the molecular patterns of HBV isolates from patients with occult infection. METHODS: Serum samples from 100 patients negative for hepatitis B surface antigen undergoing hemodialysis, half of whom were positive for anti-HCV antibodies, were tested for the presence of HBV-DNA using semi-nested polymerase chain reaction (PCR). PCR products of the S gene were directly sequenced. RESULTS: HBV-DNA was detected in 15 samples. There were no significant differences in HCV status, sex, age, time of dialysis, alanine aminotransferase levels or HBV serological markers between patients with or without occult HBV infection, with the exception of antibody to hepatitis B core antigen (anti-HBc)-only serological marker (P = 0.003). All six HBV isolates that could be sequenced were of genotype A/subgenotype A1. Four of these six HBV isolates contained mutations associated with lamivudine resistance in the DNA polymerase (two with L180M/M204V and two with rt173V/180M/204V) and a specific substitution (Y100C) in the HBV small surface protein. CONCLUSIONS: HBV isolates with the identified substitutions have the potential to spread silently by nosocomial transmission within the hemodialysis unit. These results have potential implications for the management of patients with occult HBV infection undergoing hemodialysis.

Expression of Hepatitis B virus surface antigen (HBsAg) from genotypes A, D and F and influence of amino acid variations related or not to genotypes on HBsAg detection

The impact of hepatitis B virus (HBV) genotypes on the sensitivity of surface antigen (HBsAg) detection assays has been poorly investigated. Here, plasmids carrying consensus or variant coding sequences for HBV surface proteins from genotypes A, D and F, were constructed. HBsAg levels were evaluated in medium and extracts of transfected CHO cells by a commercial polyclonal-based assay. We show that HBsAg detection values of consensus forms from genotypes D and F were, respectively, 37 percent and 30 percent lower than those obtained by genotype A. However, the presence of two single variations, T143M in genotype A, and T125M in genotype D, produced a decrease of 44 percent and an increase of 34 percent, respectively, on HBsAg mean values in comparison with their consensus forms. In conclusion, HBsAg detection levels varied among HBV genotypes. However, unique amino acid substitutions not linked to genotypes, such as T125M and T143M described here, should have more implications in HBV immunological diagnostics than the set of variations characteristic of each HBV genotype.

Compliance with and response to hepatitis B vaccination in remaining quilombo communities in Central Brazil.

Compliance with and responses to the hepatitis B vaccine were evaluated in remaining quilombo communities in Central Brazil. A total of 708 individuals who were susceptible to hepatitis B virus infection were invited to participate in the hepatitis B vaccination program in eight communities. Although 567 (80%) individuals received the first dose, only 198 (28%) complied with the full vaccination scheme. Of 148 subjects who agreed to be tested for anti-HBs, 123 (83.1%; 95%CI: 75.9-88.6) responded to the vaccine. A geometric mean titer of 512mIU/mL (95%CI: 342.5-765.3) was found. Male sex and older age were independently associated with non-response. Additional health education programs and alternative hepatitis B vaccine schedules are needed to improve the vaccination coverage in these communities in Central Brazil.

Compliance with and response to hepatitis B vaccination in remaining quilombo communities in Central Brazil / Adesão e resposta à vacinação contra hepatite B em comunidades remanescentes de quilombos no Brasil Central

Compliance with and responses to the hepatitis B vaccine were evaluated in remaining quilombo communities in Central Brazil. A total of 708 individuals who were susceptible to hepatitis B virus infection were invited to participate in the hepatitis B vaccination program in eight communities. Although 567 (80 percent) individuals received the first dose, only 198 (28 percent) complied with the full vaccination scheme. Of 148 subjects who agreed to be tested for anti-HBs, 123 (83.1 percent; 95 percentCI: 75.9-88.6) responded to the vaccine. A geometric mean titer of 512mIU/mL (95 percentCI: 342.5-765.3) was found. Male sex and older age were independently associated with non-response. Additional health education programs and alternative hepatitis B vaccine schedules are needed to improve the vaccination coverage in these communities in Central Brazil.

A adesão e resposta à vacina contra hepatite B foram avaliadas em comunidades remanescentes de quilombos no Brasil Central. Um total de 708 indivíduos suscetíveis à infecção pelo vírus da hepatite B foi convidado para participar do programa de vacinação contra hepatite B em oito comunidades. Apesar de 567 (80 por cento) indivíduos terem recebido a primeira dose, somente 198 (28 por cento) aderiram ao esquema completo de vacinação. De 148 sujeitos que concordaram em dosar o anti-HBs, 123 (83,1 por cento; IC95 por cento: 75,9-88,6) responderam à vacina. Um título geométrico médio de 512mUI/mL (IC95 por cento: 342,5-765,3) foi encontrado. Sexo masculino e idade foram independentemente associados com ausência de resposta. Programas adicionais de educação em saúde e esquemas alternativos de vacinação contra hepatite B são necessários para melhorar a cobertura vacinal nessas comunidades no Brasil Central.

Epidemiological study of hepatitis A, B and C in the largest Afro-Brazilian isolated community.

This study was conducted to estimate the prevalence and molecular epidemiological features of viral hepatitis A, B and C in the Kalunga population, which represents the largest Afro-Brazilian isolated community. Among 878 individuals studied, the overall prevalence of anti-hepatitis A virus antibodies was 80.9%, with a significant rise from 44.8% to near 100% between the first and fourth decade of life. Rates for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen (anti-HBc) of 1.8% and 35.4%, respectively, were found. Increasing age, male gender, illiteracy and history of multiple sexual partners were associated with hepatitis B virus (HBV) infection. An occult HBV infection rate of 1.7% (5/295) was found among anti-HBc-positive individuals. HBV genotype A (subtype Aa) was dominant in this community. Only 5/878 individuals (0.6%) were positive for anti-hepatitis C virus (HCV). HCV RNA was detected in three of them, who were infected with genotype 1 (subtype 1a). These findings point out high, intermediate and low endemicity for hepatitis A, B and C, respectively, in the Kalunga community in Brazil. Circulation of HBV genotype A (subtype Aa) in this Afro-Brazilian isolated community indicates the introduction of this virus during the slave trade from Africa to Brazil.