BACKGROUND Hepatitis B Virus (HBV) infection is a worldwide public health problem. In the 1980's a highly effective and safe vaccine against HBV was developed, although breakthrough infection still occasionally occurs because of the emergence of escape mutants. The aim of this study was to identify HBV genotypes and escape mutants in children and their mothers in Amerindian communities of the A...

BACKGROUND Genetic variations of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) can affect diagnostic assays and therapeutic interventions. Recent changes in prevalence of subtypes/genotypes and drug/immune-escape variants were characterized by comparing recently infected vs more remotely infected blood donors. METHODS Infected donors were identified ...

Cuba is an HBsAg low-prevalence country with a high coverage of anti-hepatitis B vaccine. Its population is essentially the result of the population mix of Spanish descendants and former African slaves. Information about genetic characteristics of hepatitis B virus (HBV) strains circulating in the country is scarce. The HBV genotypes/subgenotypes, serotypes, mixed infections, and S gene mutatio...

CONTEXT Occult hepatitis B virus (HBV) status (OHBS) is simply defined as the presence of HBV DNA in the liver (with or without detectable HBV DNA in the serum), in the absence of serum HBV surface antigen (HBsAg). Importance of OHBS is mostly clinical, related to its possible role in spreading through blood transfusion and liver transplantation; causing classic forms of HBV. Mechanisms underly...

objective (s):the aim of this study was to determine the correlation between vaccine therapy and appearance of mutations in hepatitis b surface antigen (hbsag)-positive chronic hepatitis b virus (hbv) patients. materials and methods: 16 patients received the hbv vaccine and another 16 individuals from the control group did not. the surface gene was amplified and directly sequenced from samples ...

Mutations in the core promoter and precore regions of HBV cause down-regulation of HBeAg. These mutations are associated with chronic hepatitis, cirrhosis and Hepato Cellular Carcinoma (HCC). This study was carried out to sequence analysis of HBV core gene in HBsAg- positive blood donors in Iran. A total of 50 HBsAg- positive blood donor samples were examined in this study. Serological markers ...

PURPOSE Occult hepatitis B infection (OBI) among HIV positive patients varies widely in different geographic regions. We undertook a study to determine the prevalence of occult hepatitis B infection among HIV infected individuals visiting a health facility in South West Cameroon and characterized occult HBV strains based on sequence analyses. METHODS Plasma samples (n = 337), which previously...

Sera from 12 patients infected with human immunodeficiency virus and hepatitis B virus (HBV), on lamivudine as part of an antiretroviral therapy, were retrospectively analysed for the presence of HBV polymerase mutations by the line probe assay, INNO-LiPA HBV DR, and by the direct sequencing assay, TRUGENE HBV genotyping kit. Results at codons 180, 204 and 207 were compared for 44 samples. Full...

BACKGROUND We recently reported complex hepatitis B virus (HBV) drug resistant and concomitant vaccine escape hepatitis B surface antigen (HBsAg) variants during human immunodeficiency virus (HIV) co-infection and antiretroviral therapy (ART) exposure in Ethiopia. As a continuation of this report using the HBV positive sera from the same study participants, the current study further analyzed th...

BACKGROUND Escape mutations potentially allow viruses to avoid detection and clearance by the host immune system and may represent a mechanism through which infections may persist in some patients. The association of the mutations in the HBcAg gene with Hepatitis B asymptomatic carriers (ASC) has not been studied adequately. The current study was aimed to investigate HBcAg18-27 CTL epitope muta...