Hepatitis C nucleic acid

5-10 mL blood in EDTA or citrate.

Nucleic acid detection after amplification.

Diagnosis of acute hepatitis C infection prior to seroconversion in the setting of clinical disease, or follow-up of a high risk exposure incident;

screening of blood donors;

resolution of uncertain serological status (two different antibody assays with conflicting results, indeterminate immunoblot);

determination of prognosis and infectivity in patients positive for hepatitis C antibodies.

Quantitative HCV RNA (viral load) for pre-treatment evaluation and monitoring of patients receiving antiviral therapy.

Genotyping on patients with active infections should be performed to aid therapeutic decisions.

Detection of HCV RNA indicates ongoing infection and infectivity, although occasional false positives occur. A single negative result does not confirm clearance.

HCV RNA levels (viral load) do not correlate with the natural history of the disease. Their use is limited predicting likelihood of response to treatment and planning the duration of therapy. Patients with high HCV RNA levels respond less well and require a longer course of antivirals.