440. Prevalence of false-positive hepatitis C antibody tests in the National Health and Nutrition Examination Survey (NHANES), 2007-2012
Session: Poster Abstract Session: Hepatitis C
Thursday, October 27, 2016
Room: Poster Hall
Posters
  • Moorman Holmberg IDWeek POster 16-267433_SP_Hep-C_false+.pdf (121.9 kB)
  • Background: Screening large numbers of persons in a population with low prevalence of a disease leads to many false-positive test results. As hepatitis C virus (HCV) screening increases in the US, we can anticipate many false-positive results creating anxiety and confusion.

    Methods: We determined the percentage of true vs false-positive HCV antibody (anti-HCV) test results among participants in a nationally representative study (NHANES) with low HCV infection prevalence using a confirmatory recombinant immunoblot assay (RIBA) test and follow-up HCV RNA testing.

    Results: Overall, of 22,359 NHANES participants tested, 479 (2.1%) were anti-HCV screening reactive and were tested for RIBA; of 477 tested by RIBA, 323 (67.7%) were true positives (RIBA-positive), and 105 (22%) were false positives (RIBA-negative) (see Figure). Many others (49, 10.3%) were RIBA indeterminate of which only 2 (4.9%) represented active infection. Ultimately, of 424 with more (RIBA and HCV RNA) testing, 218 (51.4%) were confirmed as active HCV infections.

    Conclusion: False-positive antibody assays may occur with great frequency when screening low HCV prevalence populations, emphasizing the need for �reflex� HCV RNA testing to avoid clinician and patient confusion and distress.

    Scott D. Holmberg, MD, MPH, FIDSA, Anne C. Moorman, BSN, MPH, Jan Drobeniuc, MD, PhD and Saleem Kamili, PhD, Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA

    Disclosures:

    S. D. Holmberg, None

    A. C. Moorman, None

    J. Drobeniuc, None

    S. Kamili, None

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