Highly sensitive quantitative assays of hepatitis C RNA are appropriate at the time of diagnosis (to confirm infection) and as part of antiviral therapy, which is typically at the beginning and after therapy is completed to confirm sustained virological response at week 12 (SVR 12). Outside of these circumstances the results of virologic testing do not change clinical management or outcomes.
Sources:
American Association for the Study of the Liver, Infectious Diseases Society of America. HCV Guidance: Recommendations for Testing, Managing, and Treating Hepatitis C [Internet]. 2016 Jun [cited 2017 Mar 15].