HCV Testing Approach
Begin with anti-HCV antibody testing as the first-line diagnostic test, followed by reflex HCV RNA testing to confirm active infection—this two-step approach with automatic reflex testing eliminates the need for return visits and addresses a major barrier in the HCV care continuum. 1
Initial Screening Strategy
Anti-HCV antibody testing is the first-line diagnostic test for HCV infection, with both laboratory-based enzyme immunoassays and rapid point-of-care tests having similar sensitivity and specificity. 2, 3
Implement reflex HCV RNA PCR testing automatically when antibodies are positive—this requires only a single blood collection and prevents patients from being lost to follow-up between antibody and confirmatory testing. 1
Rapid diagnostic tests using serum, plasma, fingerstick whole blood, or crevicular fluid (saliva) can be used instead of classical enzyme immunoassays to facilitate screening and improve access to care. 2
Dried blood spot collection can be used for sequential antibody and reflex RNA testing in rural or difficult-to-access populations, requiring only a fingerstick rather than venipuncture. 1
Test Result Interpretation
Positive antibody + Positive HCV RNA = Current active infection requiring treatment evaluation. 1, 3
Positive antibody + Negative HCV RNA = Past resolved infection or false positive—inform patients they do not have current infection but are not protected from reinfection. 1, 3
Negative antibody = No evidence of current or past infection (unless recent exposure or immunocompromised status applies). 1
Anti-HCV positive, HCV RNA-negative individuals should be retested for HCV RNA 3 months later to confirm definitive clearance. 2
Special Testing Situations
Acute Hepatitis or Immunocompromised Patients
HCV RNA testing should be part of the initial evaluation when acute hepatitis C is suspected or in immunocompromised patients, as antibody production may be delayed or inadequate. 2, 3
For suspected acute infection, perform both HCV antibody and HCV RNA testing simultaneously due to exposure, clinical presentation, or elevated aminotransferase levels. 2
Recent Exposure (Within 6 Months)
- For individuals with recent exposure and negative antibody tests, perform HCV RNA testing or follow-up HCV-antibody testing ≥6 months after exposure. 1
Risk for Reinfection
For patients at risk for reinfection (e.g., after prior clearance), use HCV RNA testing as the primary test since antibody tests will remain positive after prior clearance. 1, 3
Annual testing is specifically recommended for people who inject drugs and men with HIV who have unprotected sex with men. 1
Who Should Be Screened
Universal one-time screening for all adults aged 18-79 years is recommended. 1
Risk-based screening for persons <18 years with risk factors, such as those with a history of injection drug use. 1
Periodic testing for those with ongoing risk factors, with frequency determined by individual risk assessment. 1
Pre-Treatment Testing Requirements
Test all patients for evidence of current or prior HBV infection by measuring hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) before initiating HCV treatment—HBV reactivation has resulted in fulminant hepatitis, hepatic failure, and death. 4, 5
Quantitative HCV RNA testing is recommended prior to antiviral therapy to establish baseline viral load. 1, 3
HCV genotype testing may be considered when it would alter treatment recommendations, though this is becoming less necessary with pangenotypic direct-acting antiviral regimens. 1, 3
Critical Pitfalls to Avoid
Relying solely on antibody testing without reflex RNA testing will miss active infections or incorrectly classify resolved infections as current—this is the most common diagnostic error. 1
Failure to implement automatic reflex RNA testing leads to patients being lost to follow-up between antibody and confirmatory testing, resulting in delayed diagnosis and treatment. 1
Using only antibody testing in previously infected patients will miss reinfection—always use HCV RNA testing in this population. 1
Missing the diagnosis in high-risk groups, especially people who inject drugs or immunocompromised patients, can have significant consequences for morbidity and mortality. 1