Testing for Hepatitis C: New Guidance

Hello. I am Dr. Chong-Gee Teo, the Laboratory Branch Chief in the Division of Viral Hepatitis at the Centers for Disease Control and Prevention (CDC). As part of Medscape's CDC Expert Commentary Series, I will be speaking with you about CDC's updated guidance for clinicians and laboratorians for testing for hepatitis C virus (HCV) infection, released in May 2013.^[1]

In 2003, CDC published guidelines^[2] for the laboratory testing and result reporting of antibody to HCV. CDC is now issuing updated guidance because of some new developments:

• The wider availability of a rapid test for HCV antibody;

• The discontinuation of the recombinant immunoblot assay (RIBA), which has been used for supplemental testing of HCV antibody; and

• Evidence that many persons who are identified as reactive by an HCV antibody test might not subsequently be evaluated to determine whether they have current HCV infection.^[3]

These developments have occurred in the background of significant advances in the availability of antiviral agents with improved efficacy against HCV.

Although previous guidance focused on strategies to detect and confirm HCV antibody, reactive results from HCV antibody testing cannot distinguish between persons whose past HCV infection has resolved and those who are currently HCV infected.^[4] Accurate testing to identify current infection is important so that preventive services, care, and treatment can be offered.

The recommended testing sequence begins with a US Food and Drug Administration (FDA)-approved test for HCV antibody, either a rapid or a laboratory-conducted assay for HCV antibody in blood. A nonreactive HCV antibody result indicates that no HCV antibody was detected.

A reactive result indicates 1 of 3 outcomes:

• Current HCV infection;

• Past HCV infection that has resolved; or

• False positivity.

A reactive result for HCV antibody should be followed by an FDA-approved nucleic acid testing (NAT) assay intended for detection of HCV RNA. If HCV RNA is detected, that indicates current HCV infection. If HCV RNA is not detected, that indicates either past (resolved) HCV infection or false HCV antibody positivity.

Testing for hepatitis C should be initiated with a test for antibody to HCV, and all reactive results should be followed by a test for HCV RNA.

The bottom line: HCV testing must ensure the identification of persons with current HCV infection.

Web Resources

Testing for HCV Infection: An Update of Guidance for Clinicians and Laboratorians

Recommended Testing Sequence for Identifying Current Hepatitis C Virus (HCV) Infection

Interpretation of Results of Tests for Hepatitis C Virus (HCV) Infection and Further Actions

CDC: Hepatitis C Information for Health Professionals

Chong-Gee Teo, MD, PhD, joined the CDC as Chief, Laboratory Branch, Division of Viral Hepatitis, in 2005. Before that, he was with the Virus Reference Laboratory of Health Protection Agency, London, United Kingdom, where he was head of the Bloodborne and Oral Viruses Unit.

Public Information from the CDC and Medscape

Cite this: Testing for Hepatitis C: New Guidance - Medscape - Jul 29, 2013.