Hepatitis C is curable, but only for people who know they have it — and a positive screening test does not tell them. Diagnosis takes two steps: an antibody test, and, if that is reactive, an HCV RNA test showing whether the virus is still present. Historically, about one third of patients stopped at step one. In 2023, CDC told every site that screens for hepatitis C to close that gap: collect the samples in a single visit, and run the RNA test automatically.
Why two tests
| Antibody test | RNA test | What it means |
|---|---|---|
| Reactive | Detectable | Current infection — link to care and curative treatment |
| Reactive | Undetectable | Most likely a resolved past infection, though a falsely reactive antibody test is possible |
| Reactive | Not done | Incomplete testing — no diagnosis |
The care cascade in the United States shows a large drop between the people with a reactive antibody test and those who get the RNA test. Completing both — "complete testing" — is critical to CDC's goal of eliminating hepatitis C nationally.
Four ways to do it, one to stop
CDC's 2013 testing guidance described four operational strategies:
| Strategy | How the RNA sample is obtained | Visits |
|---|---|---|
| 1 | A second blood draw, taken later, after a reactive antibody result | Two |
| 2 | Two tubes drawn at a single venipuncture: one for antibody, one held for RNA | One |
| 3 | The same blood sample is reflexed to RNA testing if the antibody is reactive | One |
| 4 | A finger-stick antibody test, with a separate blood sample collected for RNA | One |
Strategy 1 depends on the patient coming back — and many do not. "Automatic" testing means the laboratory runs the RNA test with no further action by patient or provider.
The evidence
After a meeting convened by the Association of Public Health Laboratories in October 2021, CDC reviewed the published studies:
| Setting | With a second visit (strategy 1) | With automatic testing |
|---|---|---|
| Veterans Health Administration | 64% completed testing | 98% |
| Cherokee Nation Health Services | 68% | 85% after switching |
| Chronic Hepatitis Cohort Study | 62% had complete testing | — |
| New York City surveillance | 66% had complete testing — prompting a 2015 requirement that all laboratories test automatically | — |
| Mid-Atlantic Permanente Medical Group | historical approach | a care pathway with automatic RNA testing diagnosed significantly more current infections |
Since 2018, VA directive 1300.01 has required automatic RNA testing of every antibody-reactive specimen. Strategy 1 has also been found not cost-effective.
The updated guidance
- Stop using strategy 1. Use strategy 2, 3 or 4.
- Where antibody testing uses finger-stick blood, collect a separate sample at the same visit so the RNA test can be completed.
- Perform an RNA test on every antibody-reactive sample; without it, testing is incomplete.
- Health care facilities and laboratories should update their practices accordingly.
Doing both steps from one visit means more people with current infection are diagnosed, linked to care and given curative antiviral therapy.
Sources
Based on Cartwright EJ, Patel P, Kamili S, Wester C, "Updated Operational Guidance for Implementing CDC's Recommendations on Testing for Hepatitis C Virus Infection," MMWR Morbidity and Mortality Weekly Report 2023;72(28), Centers for Disease Control and Prevention; a work of the United States government in the public domain.
Licence: CC0 1.0 (public domain) · Adapted from www.cdc.gov
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