Background The presence of HBV DNA in the liver (with detectable or undetectable HBV DNA in the serum) of individuals tested HBsAg negative by currently available assays is defined occult B Infection (OBI). It remains a potential transmission threat and risk to HBV chronic infection. The purpose of this study was to determine the OBI prevalence among HBsAg negative subjects and to characterize ...

The molecular and cellular basis of long-term T cell memory against viral antigens is still largely undefined. To characterize anti-viral protection by memory T cells against non-cytopathic viruses able to cause acute self-limited and chronic infections, such as the hepatitis B virus (HBV), we studied HLA class II restricted responses against HBV structural antigens in 17 patients with acute he...

Quality-control serum is produced by pooling human serum. This serum is not usually assayed for Australia antigen (also termed Hepatitis B antigen, HB Ag, or HAA). We undertook the present study to determine which, if any, of our present quality-control serum were HB Ag positive. By so doing we hoped we could eliminate the positive sera and thus lessen the possibility of technologists contracti...

Early diagnosis of infection like Hep-B virus in blood is important for low cost medical treatment. For this purpose, it is desirable to develop a point of care device which should be able to detect trace quantities of the target molecule in blood. In this paper, we report a nanoporous silicon oxide sensor which is capable of detecting down to 1fM concentration of Hep-B surface antigen in blood...

This study compared the assay results of HBV markers obtained with two automated immunoassay systems in serum samples with concomitant HBV antigens and antibodies. Eighty-nine samples of concomitant HBsAg and anti-HBs and 74 samples of concomitant HBeAg and anti-HBe were analyzed by the Abbott Architect i2000 and the Roche Elecsys 2010 immunoassay systems. The overall concordance rates of the A...

AIM To investigate whether HLA class I polymorphisms could influence the clearance of hepatitis B surface antigen (HBsAg) in Qidong Han population. METHODS We genotyped HLA-A, -B, and -C loci of 448 individuals with HBV persistent infection and 140 persons with spontaneous clearance of HBsAg by polymerase chain reaction with sequencing based typing (PCR/SBT). All the individuals were unrelate...

Chronic hepatitis B virus (HBV) infection affects millions of people worldwide and about a half million people die every year. India represents the second largest pool of chronic HBV infection worldwide with an estimated 40 million infected people. The prevalence of chronic HBV infection in pregnant women is shown to be 0.82 per cent with the risk of mother-to-child vertical transmission. Hepat...

Disease prevention through vaccination is considered to be the greatest contribution to public health over the past century. Every year more than 100 million children are vaccinated with the standard World Health Organization (WHO)-recommended vaccines including hepatitis B (HepB). HepB is the most serious type of liver infection caused by the hepatitis B virus (HBV), however, it can be prevent...

The duration of protection after hepatitis B vaccination in children is unknown. We determined the serum level of antibody to hepatitis B surface antigen (anti-HBsAg) in 273 randomly selected 7-9-year-old schoolchildren from Zanjan City, Islamic Republic of Iran, who had been fully vaccinated against hepatitis B starting at birth. Titres < or = 10 mlU/mL were considered unprotective. Just over ...

BACKGROUND/AIMS Clearance of hepatitis B virus (HBV) is characterised by a strong cytotoxic T cell response. Persistence of HBV in chronic hepatitis B carriers may be related to failure of this response. The aim of this study was to determine whether HLA class I restricted cytotoxic T lymphocyte (CTL) responses persist in anti-hepatitis B e (HBe) positive / HBV DNA negative individuals, and to ...