Publications by authors named "Clara Fumiko Tachibana Yoshida"

Detection of hepatitis B virus (HBV) serological markers in dried blood spot (DBS) samples by enzyme immunoassay (ELISA) has not yet been fully optimized. In this study, the ability to detect three HBV markers (HBsAg, anti-HBc, and anti-HBs) was evaluated in DBS samples using a modified commercial ELISA. Matched serum and DBS samples were obtained from individuals with or without a past history of HBV infection.

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In this study, a modified enzyme immunoassay (EIA) was evaluated for the Hepatitis B surface antigen (HBsAg) among whole saliva and oral fluid samples. Specimens were collected from 115 individuals who gave serum and oral fluid using Salivette (Sarstedt, Nümbrecht, Germany) and whole saliva. Saliva specimens were tested following a modified ELISA, and the results were compared with paired serum specimens that were tested according to the supplier's instructions.

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Background: The natural outcome of infection with hepatitis C virus (HCV) varies substantially among individuals. However, little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection.

Methods: From 1 January 2001 through 31 December 2008, a consecutive series of 65 patients from Rio de Janeiro, Brazil, with a well-documented diagnosis of acute HCV infection, acquired via various routes, were enrolled in this study.

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Background/aims: Detection of HCV has been documented in extrahepatic sites such as platelets. However, its influence on antiviral therapy outcome is unknown. In this study, we investigated the relationship between the detection of HCV in platelets from a cohort of 48 chronically HCV-infected patients and response to antiviral therapy.

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This article aimed to estimate the prevalence of hepatitis C in Botafogo, a district of Bebedouro, São Paulo State, Brazil, and investigate possible risk factors. One individual over 18 years of age was selected from each household to answer a questionnaire on socio-demographic variables and factors associated with hepatitis C. Blood samples were also drawn for immunoenzymatic tests.

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Background: Injecting drug users (IDU) have a key role in Hepatitis C Virus (HCV) epidemiology. Young/short-term IDUs constitute a target group for preventive/harm reduction interventions.

Objectives: To investigate HCV transmission among young/short-term (ST) and long-term (LT) IDUs, from the perspective of epidemiology and molecular biology.

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Background: Haemodialysis (HD) continues to carry the risk of hepatitis C virus (HCV) transmission, with delayed seroconversion and often normal alanine aminotransferase (ALT) values increasing the likelihood of undetected infection and thus uninterrupted spread of HCV. The aim of this study was to identify the characteristic patterns of ALT changes and seroconversion during an outbreak of HCV in a HD unit. We also wanted to establish the relationship between infecting viruses using molecular analysis.

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In Argentina, most information on hepatitis C virus (HCV) genotype distribution comes from studies carried out in Buenos Aires (east province). In order to identify HCV subtypes in central Argentina, nucleotide sequencing of core region was performed in samples from 36 patients living in Córdoba, the second most populated province of Argentina. The sequence analysis identified subtype 2c as the most prevalent (50%), followed by subtype 1b (33%) and to a lesser extent by subtypes 1a (11%), 3a (3%) and 4a (3%).

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Background/aims: Interaction of platelets with HCV is presumed to be one of the pathogenic mechanisms implicated in HCV-associated thrombocytopenia. Nevertheless, analysis of factors influencing the detection of HCV in platelets is not well understood. In this study, we investigated the relationship between the detection of HCV in platelets from a cohort of 39 chronically HCV-infected patients and several viral and host factors.

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Background: Epidemiological studies on viral hepatitis (VH) using new technologies raise ethical issues especially concerning community-based studies on seroprevalence (CSS), sentinel surveillance-based studies (SBS) the use of blood-bank registers (BBR) and serum stocks (SS).

Methods: Positive (PA) and negative (NA) aspects of these different designs are discussed, pointing to alternatives, according to Resolution CNS n masculine 196/96.

Results: Priority for research is justified by VH magnitude, severity, and vulnerability, and need for development of diagnosis/therapy protocols and prevention/control strategies.

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The context of first drug injection and its association with ongoing injecting practices and HCV (hepatitis C virus) infection were investigated. Injection drug users (IDUs) (N = 606) were recruited in "drug scenes" (public places, bars) in Rio de Janeiro, Brazil, interviewed, and tested for HCV. Sharing of needles/syringes was more prevalent at the first injection (51.

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Chronic hepatitis C virus (HCV) infection has also been associated with the development of several extrahepatic alterations, including thrombocytopenia, and a variety of pathogenic mechanisms are reported to be implicated in this hematological abnormality. Different studies have succeeded in detecting HCV in platelets with discrepant results. Moreover, most of the studies on HCV-associated thrombocytopenia have failed to provide data concerning the infecting genotype, a factor with prognostic implication in chronically HCV-infected patients.

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A seroprevalence study was carried out among a group of women in Rio de Janeiro to determine the prevalence of different markers for viral hepatitis given the limited data among healthy populations. Blood samples collected and tested from 874 women before or after delivery in a public county maternity hospital demonstrated age to be directly related to markers for hepatitis A virus and hepatitis B virus (HBV) infection. The prevalence of HBV and hepatitis C virus infection were lower than that observed in the blood donor population and might be explained by the younger age group and gender.

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The immunogenicity of a Hepatitis B vaccine was evaluated in 110 neonates (57 full term and 53 preterm) born to Hepatitis B surface antigen (HBsAg) negative mothers. Three 10 microg doses of recombinant Hepatitis B vaccine were administered: the first dose within the first week of life; the second between 1 and 2 months; and the third at 5-7 months of age. Anti-HBs antibody titres were measured 3 months after the third dose.

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