Tests and screening strategies for the diagnosis of hepatitis C.

The threshold for testing for hepatitis C virus (HCV) should be low for persons with any risk factor for HCV infection. Current practice calls for first screening for antibodies to HCV and then testing for HCV RNA in those in whom antibodies are detected. Viral testing can distinguish between active and resolved HCV infection and also determine viral load, which can help predict response to antiviral therapy. Many highly sensitive assays are available for testing for HCV RNA. Once HCV infection is diagnosed, the HCV genotype should be determined to help predict treatment response and duration. Liver biopsy can aid in disease staging and help guide treatment decisions. Practical and efficient screening strategies for HCV are guided by risk factors for HCV infection.