Basal core promoter and precore mutations among hepatitis B virus circulating in Brazil and its association with severe forms of hepatic diseases

BACKGROUND In Brazil, few studies have investigated the prevalence of infection with the precore (PC) and basal core promoter (BCP) mutants of the hepatitis B virus (HBV). OBJECTIVES This study aimed to analyse the frequency of PC and BCP mutations among patients infected with HBV and to evaluate the association between the variants and advanced hepatic disease. METHODS A total of 161 patients infected with HBV were studied. To identify PC and BCP mutations, a 501-bp fragment of HBV DNA was amplified and sequenced. FINDINGS PC and BCP regions from HBV strains were successfully amplified and sequenced in 129 and 118 cases, respectively. PC and BCP mutations were detected in 61.0% and 80.6% of the cases, respectively. The A1762T/G1764A variant was identified in 36.7% of the patients with grade 1 and 2 liver fibrosis (29/79) and in 81.8% of the patients with grade 3 and 4 liver fibrosis (9/11) (p < 0.01); in 76.9% of the patients with cirrhosis (10/13) and in 38.1% of the patients without cirrhosis (40/105) (p = 0.01); and in 77.8% of the patients with hepatocellular carcinoma (HCC) (7/9) and in 39.4% of the patients without HCC (43/109) (p = 0.03). MAIN CONCLUSIONS A high prevalence of HBV PC and BCP mutants was found. The A1762T/G1764A variant was independently associated with advanced forms of liver fibrosis, hepatic cirrhosis, and HCC.

Distribution of HBV subgenotypes in Ribeirão Preto, Southeastern Brazil: a region with history of intense Italian immigration

Abstract Hepatitis B virus (HBV) is distributed worldwide, with geographical variations regarding prevalence of the different genotypes. The aim of this study was to determine the HBV genotypes and subgenotypes circulating in Southeast Brazil and compare the genetic sequences found with HBV sequences previously described in the world. Sequences from 166 chronic HBV carriers were analyzed using the fragment constituted by 1306 base pairs comprising surface and polymerase regions of the HBV genome. The sequences obtained were submitted to phylogenetic analysis. HBV subgenotypes A1, A2, D1-D4, F2a, and F4 were found. HBV genotype D was the most frequent, found in 99 patients (58.4%). Within this group, subgenotype D3 was the most prevalent, in 73 patients (42.9%). HBV genotype A was identified in 58 (36%) patients, subgenotype A1, in 48 (29.8%) subjects. Genotype F was identified in 9 (5.4%). According to the phylogenetic analysis, the sequences found were grouped with sequences from Europe, Asia and Middle East (subgenotypes D1, D2, D3) and sequences from Latin America and Africa (subgenotype A1). HBV D3 grouped in different clusters inside D3 clade, several of them with sequences isolated in Italy. We also identified eight families whose relatives were infected with the same HBV subgenotype, most with high similarity between sequences. In conclusion, the distribution of the HBV sequences obtained interweaved with sequences from other continents, corresponding to regions from where many immigrants came to this region, in accordance to the hypothesis that the HBV detected over there were brought during the colonization times.

Risk factors for hepatitis C virus transmission in the municipality of Catanduva, State of São Paulo: a case-control study

Introduction Hepatitis C virus (HCV) is primarily transmitted via contact with the blood of infected patients, although the form of contact has not been identified for a significant percentage of carriers. The present study evaluated possible risk factors for HCV transmission in a medium-sized town located in the northwest region of the State of São Paulo. Methods This was a case-control study, with the case group consisting of 190 chronic HCV carriers older than 18 years residing in the municipality of Catanduva. The control group also consisted of 190 individuals with HCV-negative serology. The groups were paired (1:1) for gender, age range (± five years), and place of residence. The same structured questionnaire was applied to all subjects, who gave written informed consent to participate in the study. The data were statistically analyzed using crude and adjusted logistic regression, and the results were expressed as odds ratios with a 95% confidence interval. Results The demographic profiles of the groups indicated a predominance of males (68.9%) and mean ages of 47.1 years (case group) and 47.3 years (control group). After adjusting for conditional regression, the following factors were found to represent risks for HCV: history of sexually transmitted disease (STD) and blood transfusion; accidents with syringes and/or needles; tattoos; and the use of non-injectable drugs and injectable medications. Conclusions The transmission of HCV via the blood route has been well characterized. Other forms of contact with human blood and/or secretions are likely to transmit the virus, although with a lower frequency of occurrence. .

Clinical, demographic and epidemiological characteristics of patients with hepatitis B followed at a university hospital in southeastern Brazil: predominance of HBeAg negative cases / Características clínicas, demográficas e epidemiológicas dos pacientes com hepatite B em seguimento em hospital universitário no sudeste do Brasil: predominância de casos HBeAg negativos

INTRODUCTION: Hepatitis B is common in Brazil, although there are regional differences regarding the degree of endemicity, the most frequent forms of transmission and the presence of different evolutive stages of chronic disease. The present study aimed to determine the clinical, demographic and epidemiological characteristics of patients chronically infected with hepatitis B virus (HBV) residing in the Ribeirão Preto region, southeastern Brazil. METHODS: A total of 529 medical records of individuals with HBV monoinfection were reviewed. RESULTS: More than 60 percent of the subjects were males, with a mean age of 38 years-old. The HBeAg-negative serological pattern was verified in 84.4 percent of the patients, among whom the risk of vertical/intrafamily transmission was 43.2 percent (p = 0.02). The consumption of alcohol in amounts exceeding 20g a day was observed in 21.3 percent of the subjects and was more frequent among men (33 percent) (p < 0.001). Among patients with cirrhosis, 54.1 percent were alcohol abusers (p = 0.04), all of them males. The presence of cirrhosis was more frequent in the HBeAg-positive group (24.4 percent) than in the HBeAg-negative group (10.2 percent) (p < 0.001). CONCLUSIONS: High proportions of HBV-infected subjects with an HBeAg-negative pattern were observed, with a higher risk of vertical/intrafamily transmission. Alcohol abuse was associated with male subjects and with cirrhosis of the liver in this group. A tendency toward an increase in the number of HBeAg-negative cases was observed over time.

INTRODUÇÃO: No Brasil, a hepatite B é comum. No entanto, há diferenças regionais no que diz respeito ao grau de endemicidade, as formas de transmissão mais encontradas e a presença dos diferentes estágios evolutivos da doença crônica. O objetivo deste trabalho foi o de conhecer características clínicas, demográficas e epidemiológicas de pacientes cronicamente infectados pelo vírus da hepatite B (HBV), residentes na região de Ribeirão Preto, no sudeste do Brasil. MÉTODOS: Foi realizada a análise retrospectiva de 529 prontuários de indivíduos com monoinfecção pelo HBV. RESULTADOS: Mais de 60 por cento eram masculinos, a média de idade foi de 38 anos. O padrão sorológico HBeAg negativo foi encontrado em 84,4 por cento dos pacientes, entre os quais o risco para transmissão vertical/intrafamiliar foi de 43,2 por cento (p = 0,02). Verificou-se uso de álcool em quantidades maiores que 20g ao dia em 21,3 por cento dos indivíduos, sendo mais frequente entre os homens (33 por cento) (p < 0,001). Entre os pacientes com cirrose, 54,1 por cento faziam uso abusivo de bebidas alcoólicas (p = 0,04), sendo todos estes do gênero masculino. A presença de cirrose foi maior no grupo HBeAg positivo (24,4 por cento) que no grupo HBeAg negativo (10,2 por cento) (p < 0,001). CONCLUSÕES: Observaram-se elevadas proporções de indivíduos com infecção pelo HBV com padrão sorológico HBeAg negativo, entre os quais houve maior risco para a transmissão vertical/intrafamiliar. O uso abusivo de álcool esteve associado a indivíduos do sexo masculino e, neste grupo, à cirrose hepática. Observou-se tendência ao aumento no número de casos HBeAg negativo ao longo do tempo.