Genotyping and viral load testing are predictive of the response to interferon therapy. For any individual patient, however, the predictive value of these tests is not high enough to be used as a means of excluding a patient from treatment on the basis of the results of such testing. Even in patients with a high viral load or a specific genotype, a proportion will respond to interferon therapy, and should be allowed an empirical trial of this form of treatment. Detection of viraemia during the course of interferon therapy has a higher predictive value than pretreatment determinations, and may be used to guide decisions regarding the continuation of therapy.
MSAC recommended that on the strength of evidence pertaining to Hepatitis C Viral Load Testing public funding should be supported for these procedures providing the use of these tests is restricted to the consultant physicians who will manage the treatment and is only used for patients with confirmed hepatitis C (by ELISA or PCR test) who undertake antiviral therapy.