Detection of hepatitis C virus infection

Diagnosis and treatment of hepatitis C virus (HCV) infection relies heavily on laboratory assays such as serological tests, which include the detection of anti-HCV antibody and core antigen, and nucleic acid tests (NAT) , which include the detection of qualitative/quantitative HCV RNA and genotypes/subgenotypes.Anti-HCV testing is simple, rapid and cheap for the screening of HCV infection.But it has a longer window period and not applicable in the immunosuppressed population.NAT provides direct evidence for the presence of HCV.Qualitative HCV RNA test has been used for blood screening due to its high sensitivity.Meanwhile quantitative HCV RNA testing has been widely used to monitor the antiviral response to treatment.With the development of real-time quantitative PCR the qualitative RNA assays are being replaced by the quantitative ones.Recently HCV core antigen assay and the combination antigen-antibody assay have been introduced for the early diagnosis of HCV, whereas they still remain less sensitive than NAT.Assays for the determination of HCV genotype based on sequencing, reverse hybridization or real-time PCR are highly consistent in determining genotypes.Whereas they are not very consistent in determining subtypes and need to be improved.