title: Occult hepatitis C virus infection and its relevance in clinical practice.
abstract: Hepatitis C virus (HCV) can persist in the liver, lymphoid (immune) cells, and serum of individuals long after an apparently complete therapy-induced or a spontaneous resolution of hepatitis C. This essential asymptomatic infection, called secondary occult HCV infection (OCI), usually occurs in anti-HCV antibody reactive individuals with normal liver function tests. This infection has been identified when the nucleic acid amplification assays of enhanced sensitivity were applied for the detection of HCV genome and its replication. In addition to the secondary OCI, a form of low-level HCV-RNA-positive infection of unknown etiology coinciding with moderately elevated serum liver enzymes and progressing in the absence of anti-HCV detectable by standard clinical assays has been reported. Because of its undefined origin, it can be termed cryptogenic OCI. In this review, the general characteristics of OCI, the ways of its detection and associated controversies, and the potential clinical implications of its existence will be concisely outlined.
authors.affiliation: Molecular Virology and Hepatology Research Group, Division of Biomedical Sciences, Faculty of Medicine, Health Sciences Center, Memorial University, St. John's, NL, Canada A1B 3V6.
authors.forename: Tram Nq
authors.initials: TN
authors.lastname: Pham
authors.affiliation: Molecular Virology and Hepatology Research Group, Division of Biomedical Sciences, Faculty of Medicine, Health Sciences Center, Memorial University, St. John's, NL, Canada A1B 3V6.
authors.forename: Tomasz I
authors.initials: TI
authors.lastname: Michalak
keywords: CHC, chronic hepatitis C; Clinical practice; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; IFN, interferon; IU, international unit; NAH, nucleic acid hybridization; OCI, occult HCV infection; PBMC, peripheral blood mononuclear cells; PCR, polymerase chain reaction; RBV, ribavirin; RNA, ribonucleic acid; SVR, sustained virological response; hepatitis C; identification of OCI; occult HCV infection