HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil

ABSTRACT Background Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil. Objective To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence. Methods A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients. Results The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each. Conclusions These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

Hepatitis B virus genotypes in Southeast Brazil and its relationship with histological features

Data concerning the relationship between hepatitis B virus (HBV) genotypes and liver histology are scarce. The aim of this study was to compare HBV non-B and non-C genotypes according to demographic features, clinical status, HBV-DNA levels and liver histology in Rio de Janeiro. One hundred twenty one consecutive chronic HBV-infected patients were enrolled during two-year period and data were prospectively collected. Sera were tested for HBV genotyping using restriction fragment length polymorphism. Liver biopsy was obtained from patients with either increased alanine aminotransferase (ALT) or HBV-DNA levels. Genotype A was the most common, found in 82 (68%) patients, followed by F in 19 (15%), D in 17 (14%), B in one (1%) and C in two (2%). There was no association between HBV genotypes A, D and F and gender (p = 0.37), age (p = 0.78), race (p = 0.22), mode of infection (p = 0.94), HB "e" antigen status (p = 0.37) and HBV-DNA levels (p = 0.47). The ALT levels were lower in genotype D (75%) compared with A (47%) and F (55%) (p = 0.05). Liver biopsy showed lower inflammation [histological activity index (HAI) = 4] and fibrosis (F) (= 0) scores in genotype D than in genotypes A (HAI = 5, p < 0.001; F = 2, p = 0.008) or F (HAI = 5, p = 0.009; F = 2, p = 0.01). Genotype A was the most prevalent in chronic HBV-infected patients and genotype D patients presented with less intense liver disease.

Distribution of HBV Genotypes in Patients With Chronic HBV Infection in Korea / 대한간학회지

BACKGROUND/AIMS: Chronic HBV infection is associated with a wide spectrum of clinical manifestations, including asymptomatic carrier state, chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Genotypically, HBV genomes have been classified into seven groups, designated A to G. Several studies have suggested recently that HBV genotypic differences influence the severity of liver disease and clinical outcomes. The distribution of HBV genotypes in Korea and its clinical relevance are poorly understood. We investigated the prevalence of HBV genotypes in Korea and the association between the distinct genotypes and the severity of liver disease. METHODS: A total of 214 HBV-DNA positive serum samples, were used for the genotyping. All patients were HBV-bDNA positive chronic HBsAg carriers. 199 patients were histologically verified with liver cirrhosis (6), chronic hepatitis (192) and fatty liver (1). The other patients were clinically diagnosed with liver cirrhosis (13) or hepatocellular carcinoma (2). HBV genotype was determined by PCR using type-specific primers. RESULTS: Genotyping was possible in all patients. Out of 214 patients, 213 (99.5%) were HBV genotype C. Only one (0.5%) was genotype A. The patient with genotype A had minimal hepatitis as diagnosed by liver biopsy. CONCLUSIONS: These results indicate that almost all chronic HBV infections are genotype C in Korea. HBV genotypic difference therefore does not influence the clinical outcome of HBV infection in Korea. Because genotype C may be associated with more severe liver disease, the predominance of genotype C in Korea may result in more severe outcomes than in other countries where other genotypes are predominant.

Prevalence of HBV Genotypes in Korean Patients with Chronic Hepatitis B / 대한간학회지

BACKGROUND/AIMS: Hepatitis B virus (HBV) genotypes have distinct geographic distributions. The possibility of pathogenic differences among HBV genotypes has been suggested. We investigated the prevalence of HBV genotypes in Korea and the association between distinct genotypes and clinical outcomes. METHODS: Using a PCR-RFLP and sequencing, HBV genotypes were determined in 136 patients with chronic type B hepatitis. RESULTS: The genotype C was detected in 131 patients (96.3%), and other 5 patients (3.7%) had genotype B. There were no significant differences in sex, age, disease duration, ALT level, HBeAg/anti-HBe status, or HBeAg loss between genotype B and C patients. CONCLUSIONS: These results suggest that almost all patients with chronic hepatitis B are infected with genotype C. Genotypes do not influence the outcome of chronic hepatitis B patients in Korea.