background nucleus(t)ide analogs (nas), containing lamivudine (lmv), adefovir dipivoxil (adv), endeavor (etv), telbivudine (ldt), and tenofovir (tdf) are widely used for the treatment of chronic hepatitis b (chb), but long term anti-hepatitis b virus (hbv) therapy with nas may give rise to the emergence of drug-resistant viral mutants. objectives this study aimed to find and identify some new r...

Background: Genetic changeability of hepatitis B virus (HBV) signifies a challenge for the sensitivity of immunologic and molecular diagnostics. Therefore, knowing the spread of HBV genotypes (GENs) and mutation has considerable impacts on treatment strategies, vaccination program, diagnosis, and prevention. The present study aimed to detect HBV GENs and mutants in HBsAg-positive patients. Meth...

OBJECTIVES Persistent hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in sub-Saharan Africa. The HIV epidemic has the potential to affect its biology. Immunisation protocols established in the pre-HIV era are based upon data showing predominantly horizontal infant transmission. This study aimed to determine whether HIV co-infection will change the epidemiology of H...

SIV(mac239) infection of rhesus macaques (RMs) results in AIDS despite the generation of a strong antiviral cytotoxic T lymphocyte (CTL) response, possibly due to the emergence of viral escape mutants that prevent recognition of infected cells by CTLs. To determine the anatomic origin of these SIV mutants, we longitudinally assessed the presence of CTL escape variants in two MamuA*01-restricted...

Hepatitis B virus (HBV) infection continues to be a major health problem worldwide. The large-scale immunization programs for persons in high-risk groups, newborns, and adolescents have greatly reduced the incidence of new infection, but the ∼400 million HBV carriers with HBV surface antigen (HBsAg) in the blood remain a burden that will dwindle only within decades. Furthermore, an unknown dise...

Transfusion of blood and blood preparations is indispensible in modern medicine, and the processes of delivering a transfusion to a patient provide additional opportunity for risk, despite the remarkable progress. A spectrum of blood-borne infectious agents is transmitted through transfusion of infected blood donated by apparently healthy and asymptomatic blood donors. The diversity of infectio...

The complete genome sequences of hepatitis B virus (HBV) from 12 HBV-infected Yucpa Indians of Venezuela, a group with highly endemic HBV, were amplified and sequenced. The 12 isolates were closely related to each other, with 98.6-100% nucleotide identity. A phylogenetic tree based on the complete genome indicated clearly that they were genotype F. Three individuals had evidence of infection wi...

Hepatitis B surface antigen (HBsAg) is considered the best marker for the diagnosis of hepatitis B virus (HBV) infection. Mutations of the s gene involving amino acid substitutions within the a determinant could affect the sensitivity of diagnostic tests. In the present study, HBsAg mutants were detected in 3 immunocompromised patients, previously found to be HBsAg negative and anti-HBs positiv...

CD8(+) T cells are important for the control of chronic HIV infection. However, the virus rapidly acquires "escape mutations" that reduce CD8(+) T cell recognition and viral control. The timing of when immune escape occurs at a given epitope varies widely among patients and also among different epitopes within a patient. The strength of the CD8(+) T cell response, as well as mutation rates, pat...

background: hepatitis b virus (hbv) gene and protein variations are frequently been seen in chronic patients. the aims of study were to determine the genotypes as well as the patterns of variations distribution in chronically-infected patients from the central part of iran. methods: the surface gene was amplified, sequenced and subsequently aligned using international and national iranian datab...