What tests are needed for a patient newly diagnosed with genital Hepatitis C Virus (HCV)?

Testing for Newly Diagnosed Genital HCV

I need to clarify that HCV (Hepatitis C Virus) is not a "genital" infection—it is a blood-borne virus that affects the liver. Assuming you are asking about testing needed for a patient newly diagnosed with HCV infection, here is the comprehensive testing algorithm:

Initial Diagnostic Confirmation

All patients with suspected HCV infection should first undergo anti-HCV antibody testing with reflex HCV RNA PCR testing using a single blood draw. 1, 2 This two-step approach confirms both exposure to HCV (antibody) and active infection (RNA). 3

• A positive anti-HCV antibody test followed by positive HCV RNA confirms current active infection requiring treatment evaluation 1, 2
• A positive antibody with negative RNA indicates either past resolved infection or false positive result 1
• The reflex testing approach eliminates the need for a return visit and addresses a major barrier in the HCV care continuum 1

Pre-Treatment Laboratory Evaluation

Once active HCV infection is confirmed with positive HCV RNA, obtain the following baseline tests before initiating therapy:

Essential Baseline Tests

• Quantitative HCV RNA viral load to establish baseline levels 2, 3
• HCV genotype determination (though less critical with pangenotypic direct-acting antivirals) 2, 3
• Complete blood count (CBC) 2
• Comprehensive metabolic panel including liver function tests (ALT, AST, bilirubin, alkaline phosphatase) 2
• International normalized ratio (INR) 2
• Calculated glomerular filtration rate (GFR) 2

Coinfection Screening

• Hepatitis B surface antigen (HBsAg) and anti-HBc (hepatitis B core antibody) testing is mandatory before starting HCV treatment 4, 5, 6
  • HBV reactivation has been reported during HCV treatment with direct-acting antivirals, including cases resulting in fulminant hepatitis, hepatic failure, and death 4, 5
  • Cases occur in both HBsAg-positive patients and those with resolved HBV infection (HBsAg negative, anti-HBc positive) 4, 5
• HIV antibody testing due to overlapping risk factors and impact on prognosis 2

Fibrosis Assessment

• Liver fibrosis staging should be performed to determine need for hepatocellular carcinoma surveillance 2
• This can be accomplished through non-invasive methods (FibroScan, FibroTest) or liver biopsy if indicated 2

Common Pitfalls to Avoid

• Never rely solely on antibody testing, as this misses the distinction between active and resolved infection 2, 1
• Do not skip HBV screening before HCV treatment—failure to identify HBV coinfection can result in fatal HBV reactivation during HCV therapy 4, 5
• Ensure reflex RNA testing is implemented to avoid loss to follow-up between antibody and confirmatory testing 1, 2
• Do not use ALT levels to stage disease, as ALT fluctuates and does not correlate with fibrosis stage 2
• Remember that immunocompromised patients may have false-negative antibody tests—consider direct RNA testing in these populations 2, 3

Special Testing Considerations

• For patients with recent exposure (within 6 months) and negative antibody tests, perform direct HCV RNA testing or repeat antibody testing ≥6 months after exposure, as antibody production may be delayed 8-9 weeks 2, 1
• For immunocompromised patients, consider direct HCV RNA testing as antibody production may be delayed or inadequate 2, 3
• For patients at risk for reinfection, HCV RNA testing is required since antibody tests remain positive after prior clearance 1, 2