II. Course of Anti-HCV Antibody

  1. Present in up to 70% at onset of symptoms
  2. Present in 90% of cases at 3 months
  3. Present in most cases by 6 months post-exposure

III. Screening Tests

  1. ELISA-1 (replaced by ELISA-2)
    1. Detects seroconversion 15-20 weeks after exposure
    2. Sensitivity: 81-89%
    3. Specificity: Poor (High rate of false positives)
  2. ELISA-2 (preferred Screening Test)
    1. First line test
    2. Detects seroconversion 1-6 weeks after exposure
    3. Efficacy improved over ELISA-1
      1. Test Sensitivity: 99%
      2. Test Specificity: 99%
    4. False negative tests if immunocompromised

IV. Confirmatory Tests

  1. RIBA-2 (replaced by RT-PCR for confirmation)
    1. Indication: confirm Elisa-2 (RT-PCR preferred)
    2. Small advantage over ELISA-2
  2. Reverse transcriptase PCR for HCV RNA (RT-PCR)
    1. Indication: RIBA is indeterminate
    2. Best available diagnostic test
    3. Sensitivity: High
      1. Detects very low serum and tissue levels
      2. Qualitative test detects HCV to 5-50 copies/ml
    4. Specificity: High
    5. Disadvantages
      1. Expensive
      2. Requires flawless technique for accurate results

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window