Should This Patient Have Repeat Testing?
Yes, this patient absolutely requires HCV RNA testing to determine if they have active hepatitis C infection. A positive HCV antibody test alone cannot distinguish between current infection, past resolved infection, or a false positive result, and HCV RNA testing is essential to guide clinical management 1.
Why HCV RNA Testing is Mandatory
The positive HCV antibody result indicates one of three possibilities 1:
- Current active HCV infection (acute or chronic)
- Past resolved infection (either spontaneous clearance or successful treatment)
- Biologic false positive (rare)
HCV antibodies persist indefinitely after exposure, even after successful treatment or spontaneous clearance, making antibody testing useless for determining current infection status in someone with prior hepatitis exposure 1. This is precisely why the AASLD-IDSA guidelines explicitly state that HCV RNA testing—not repeat antibody testing—is required to detect reinfection after previous viral clearance 1.
The Recommended Testing Algorithm
Reflex HCV RNA testing should ideally be performed automatically on the same blood sample used for antibody testing 2. This single-collection approach:
- Eliminates the need for a return visit 1
- Prevents loss to follow-up, which is a major barrier in HCV care 1, 2
- Provides definitive diagnosis with one blood draw 3
The CDC and AASLD-IDSA recommend using an FDA-approved quantitative or qualitative HCV RNA assay with detection sensitivity ≤25 IU/mL 1.
Interpreting the Results
If HCV RNA is detected:
- The patient has current active HCV infection requiring treatment evaluation 1, 2
- Quantitative viral load should be documented as baseline 1
- Link immediately to medical care and treatment 1
If HCV RNA is not detected:
- The patient does not have current HCV infection 1
- This indicates either past resolved infection or false positive antibody 1
- The patient is NOT protected from reinfection and should be counseled accordingly 1, 4
Critical Pitfalls to Avoid
Do not repeat HCV antibody testing 1. The AASLD-IDSA guidelines explicitly state: "Anti-HCV testing usually does not need to be repeated after the anti-HCV-positive result has been confirmed" 1. Antibody testing will remain positive regardless of current infection status 2, 4.
Do not assume treatment history means no current infection. Patients can be reinfected after successful treatment, and natural immunity does not occur with HCV 4. Given this patient's history of hepatitis "years ago," reinfection is possible if there has been any subsequent exposure.
A single negative HCV RNA result may not be definitive in all cases 1. If there is ongoing HCV infection risk or unexplained hepatic dysfunction, repeat HCV RNA testing may be warranted 1. However, for most patients with a negative RNA result and no ongoing risk factors, no further testing is needed 1.
Ongoing Monitoring Considerations
If HCV RNA testing confirms no active infection, future monitoring depends on risk factors 4: