A possible correlation between the host genetic background in the epidemiology of Hepatitis B virus in the Amazon region of Brazil

ABSTRACT: The Amazon region of Brazil is an area of great interest because of the large distribution of hepatitis B virus in specific Western areas. Seven urban communities and 24 Indian groups were visited in a total of 4,244 persons. Each individual was interviewed in order to obtain demographic and familial information. Whole blood was collected for serology and genetic determinations. Eleven genetic markers and three HBV markers were tested. Among the most relevant results it was possible to show that (i) there was a large variation of previous exposure to HBV in both urban and non-urban groups ranging from 0 to 59.2%; (ii) there was a different pattern of epidemiological distribution of HBV that was present even among a same linguistic Indian group, with mixed patterns of correlation between HBsAg and anti-HBs and (iii) the prevalence of HBV markers (HBsAg and anti-HBs) were significantly higher (P=0.0001) among the Indian population (18.8%) than the urban groups (12.5%). Its possible that the host genetic background could influence and modulate the replication of the virus in order to generate HB carrier state.

Distribution of hepatitis C virus genotypes among different exposure categories in the State of Pará, Brazilian Amazon

INTRODUÇÃO: Estudos epidemiológicos sobre a distribuição genotípica do HCV na Amazônia Brasileira são escassos. Baseado nisto, determinamos o padrão de distribuição genotípica do HCV em diferentes categorias de exposição no Estado do Pará, Amazônia Brasileira. MÉTODOS: Estudo transversal foi realizado com 312 indivíduos infectados pelo HCV, pertencentes a diferentes categorias de exposição atendidas pelo HEMOPA, CENPREN e uma clínica privada de hemodiálise em Belém. Eles foram testados quanto à presença de anticorpos anti-HCV por teste imunoenzimático, RNA-HCV utilizando PCR em tempo real e genotipados através de análise filogenética da 5' UTR. Os grupos de populações foram caracterizados epidemiologicamente de acordo com dados coletados em breve entrevista ou consulta de prontuários médicos. RESULTADOS: Em todas as diferentes categorias de exposição ao HCV, foram encontrados predomínio do genótipo 1. A distribuição genotípica do HCV em doadores de sangue (BD) foi constituída pelos genótipos 1 (94%) e 3 (6%). Todos os pacientes com doenças hematológicas crônicas (PCHD) possuíam genótipo 1. A distribuição genotípica em usuários de drogas ilícitas (DU) foi constituída pelos genótipos 1 (59,6%) e 3 (40,4%). Em pacientes em hemodiálise (PUH) foram detectados os genótipos 1 (90,1%), 2 (3,3%) e 3 (6,6%). Finalmente, a frequência entre os genótipos 1 e 3 foi significativamente diferente entre os grupos: BD e DU, PUH e DU, PUH e PCHD, e PCHD e DU. CONCLUSÕES: A frequência genotípica e distribuição de HCV em diferentes categorias de exposição no Estado do Pará mostraram predominância do genótipo 1, independentemente do possível risco de infecção.

Likely transmission of hepatitis C virus through sharing of cutting and perforating instruments in blood donors in the State of Pará, Northern Brazil

Nós determinamos os fatores de risco à infecção pelo HCV em doadores de sangue no Estado do Pará, Brasil. Foram analisados 256 doadores de sangue atendidos na Fundação HEMOPA de 2004 a 2006, sendo divididos em dois grupos: infectados e não-infectados. O diagnóstico foi realizado por PCR em tempo real. Todos os participantes responderam a questionário sobre possíveis fatores de risco, sendo a modelagem estatística feita por regressão logística simples e múltipla. Os fatores de risco à infecção foram: uso de agulhas e seringas de vidros esterilizadas em casa (OR = 4,55), realização de tratamento dentário invasivo (OR = 3,08), compartilhamento de lâminas em domicílio (OR = 1,99), compartilhamento de lâminas descartáveis em barbearias, salões de beleza (OR = 2,34), e compartilhamento de material de manicure e pedicure (OR = 3,45). As autoridades de saúde devem conscientizar a população sobre o compartilhamento de materiais perfuro-cortantes em domicílio, salões de beleza e consultórios dentários como fatores de risco à infecção.

Association of killer cell immunoglobulin-like receptor polymorphisms with chronic hepatitis C and responses to therapy in Brazil

ABSTRACT: Soroprevalence for Hepatitis C virus is reported as 2.12% in Northern Brazil, with about 50% of the patients exhibiting a sustained virological response (SVR). Aiming to associate polymorphisms in Killer Cell Immunoglobulin-like Receptors (KIR) with chronic hepatitis C and therapy responses we investigated 125 chronic patients and 345 controls. Additionally, 48 ancestry markers were genotyped to control for population stratification. The frequency of the KIR2DL2 and KIR2DL2+HLA-C^Asp80 gene and ligand was higher in chronic infected patients than in controls (p < 0.0009, OR = 3.4; p = 0.001, OR = 3.45). In fact, KIR2DL3 is a weaker inhibitor of NK activity than KIR2DL2, which could explain the association of KIR2DL2 with chronic infection. Moreover, KIR2DS2 and KIR2DS2+HLA-C^Asp80 (p < 0.0001, OR = 2.51; p = 0.0084, OR = 2.62) and KIR2DS3 (p < 0.0001; OR = 2.57) were associated with chronic infection, independently from KIR2DL2. No differences in ancestry composition were observed between control and patients, even with respect to therapy response groups. The allelic profile KIR2DL2/KIR2DS2/KIR2DS3 was associated with the chronic hepatitis C (p < 0.0001; OR = 3). Furthermore, the patients also showed a higher mean number of activating genes and a lower frequency of the homozygous AA profile, which is likely secondary to the association with non-AA and/or activating genes. In addition, the KIR2DS5 allele was associated with SVR (p = 0.0261; OR = 0.184).The ancestry analysis of samples ruled out any effects of population substructuring and did not evidence interethnic differences in therapy response, as suggested in previous studies.

Evaluation of the therapeutic response of hepatitis C in coinfected patients (HIV/HCV): a study of cases from a hospital for chronic liver diseases in the Eastern Brazilian Amazon

INTRODUCTION: The aim of this study was to evaluate the therapeutic response of hepatitis C in patients coinfected with human immunodeficiency virus (HIV-1). METHODS: A retrospective study of 20 patients coinfected with HIV-1/HCV who were treated in the outpatient liver clinic at the Sacred House of Mercy Foundation Hospital of Pará (Fundação Santa Casa de Misericórdia do Pará - FSCMPA) from April 2004 to June 2009. Patients were treated with 180µg PEG interferon-α2a in combination with ribavirin (1,000 to 1,250mg/day) for 48 weeks. The end point was the sustained virological response (SVR) rate (HCV RNA negative 24 weeks after completing treatment). RESULTS: The mean age of the patients was 40±9.5 years, of which 89% (n=17) were male, and the HCV genotypes were genotype 1 (55%, n=11/20), genotype 2 (10%, n=2/20) and genotype 3 (35%, n=7/20). The mean CD4+ lymphocyte count was 507.8, and the liver fibrosis stages were (METAVIR) F1 (25%), F2 (55%), F3 (10%) and F4 (10%). The early virological response (EVR) was 60%, the end-of-treatment virological response (EOTVR) was 45% and the SVR was 45%. CONCLUSIONS: The median HCV viral load was high, and in 85% of cases in which highly active antiretroviral therapy (HAART) was used, none of the patients with F3-F4 fibrosis responded to treatment. Of the twenty patients treated, 45% achieved SVR and 45% achieved EOTVR. Studies that include cases from a wider region are needed to better evaluate these findings.

Hepatitis B and C virus infection among Brazilian Amazon riparians

INTRODUÇÃO: As hepatites virais constituem um importante problema de saúde pública no mundo. No Brasil existem poucos estudos sobre esta questão, especialmente entre as comunidades ribeirinhas. O objetivo deste estudo foi determinar a soroprevalência das hepatites B e C virais na comunidade ribeirinha da Ilha do Pacuí, no Estado do Pará, Brasil, e investigar os principais fatores de risco principal a que está comunidade está exposta. MÉTODOS: O presente estudo avaliou amostras de sangue de 181 voluntários que responderam a um questionário epidemiológico. Análises de marcadores sorológicos foram testados com kits comerciais de ELISA para detecção de HBsAg, anti-HBc total, anti-HBs e anti-VHC. Nos pacientes reagentes para VHC, RT-PCR e um line probe assay foi realizado para identificar o genótipo viral. RESULTADOS: Na análise dos marcadores sorológicos para hepatite B, observou-se taxas de 1,1% para anti-HBc total e 19,3% para anti-HBs, o marcador sorológico HBsAg não foi encontrado nesta população. Para a hepatite C foi encontrada um soroprevalência de 8,8%, destes 62,5% tinham RNA viral. Entre os fatores de risco estudados se destacaram: a não-utilização de preservativos, o compartilhamento de instrumentos cortantes, uso de drogas ilícitas e relatos de doença na família com VHB ou VHC. CONCLUSÕES: Observamos que a cobertura de vacinação contra o VHB é baixa e uma alta prevalência da hepatite C nesta comunidade.

Prevalence and genotyping of hepatitis C virus in blood donors in the state of Pará, Northern Brazil

Given the scarcity of epidemiological information on hepatitis C virus (HCV) infection in Northern Brazil, we determined the prevalence and genotypic frequency in blood donors in the state of Pará (PA). Blood samples from all of the blood donors at the Fundação HEMOPA (blood bank of PA) from 2004-2006 were screened for the presence of antibodies to anti-HCV and samples seroreactive to anti-HCV were further tested for HCV RNA using real-time PCR. In total, 116 HCV-RNA samples were genotyped, based on maximum likelihood phylogenetic analyses, using BioEdit, Modelgenerator, PHYML and FigTree software. The population consisted of 242,726 volunteers who donated blood from 2004-2006; the most common subgroup was males between the ages of 18-29 years old (37.30%). Within the whole group, 1,112 blood donors (0.46%) had indeterminate or positive serology; among these, 28.78% were males whose ages ranged from 18-29 years. A diagnosis of chronic HCV infection was confirmed for 304 donors (60.20% males; 66.45% were 30-49 years old), resulting in a prevalence of HCV RNA in 0.13% of the samples (304 of 242,726). HCV genotyping revealed a high frequency of genotype 1 (108/116) followed by genotype 3 (8/116). This study found HCV infection to be relatively infrequent in PA; genotype 1 was most commonly isolated. This information can help guide prevention and control policies aimed at efficient diagnosis and control measures.