Discordant tuberculin skin and interferon-gamma tests during contact investigations: A dilemma for tuberculosis controllers

S. O'Neal, K. Hedberg, A. Markum, S. Schafer

Research output: Contribution to journalArticle

12 Scopus citations


Current recommendations conflict over the appropriate use of interferon-gamma whole blood assays to screen for tuberculosis (TB) infection in contact investigations. We report here on a worksite TB contact investigation in which tuberculin skin test (TST) and QuantiFERON®-TB Gold (QFT-G) were both used to identify infection among 61 co-workers. Of the 27 (44%) who had a TST ≥15 mm, 11 (41%) had negative QFT-G, raising concerns that QFT-G may not be sufficiently sensitive when used alone in contact investigations. The questionable performance of QFT-G in this setting is not unexpected, as the negative predictive value of a test decreases with increasing prevalence.

Original languageEnglish (US)
Pages (from-to)662-664
Number of pages3
JournalInternational Journal of Tuberculosis and Lung Disease
Issue number5
StatePublished - Jul 6 2009



  • Contact investigation
  • Epidemiology
  • Interferon gamma assay
  • Tuberculosis

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Infectious Diseases

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