Detection of Mycobacterium tuberculosis Infection in United States Navy Recruits Using the Tuberculin Skin Test or Whole-Blood Interferon- Release Assays
Open Access
- 1 October 2007
- journal article
- research article
- Published by Oxford University Press (OUP) in Clinical Infectious Diseases
- Vol. 45 (7), 826-836
- https://doi.org/10.1086/521106
Abstract
Background. Military personnel are at risk for acquiring Mycobacterium tuberculosis infection because of activities in close quarters and in regions with a high prevalence of tuberculosis (TB). Accurate tests are needed to avoid unnecessary treatment because of false-positive results and to avoid TB because of false-negative results and failure to diagnose and treat M. tuberculosis infection. We sought to estimate the specificity of the tuberculin skin test (TST) and 2 whole-blood interferon-γ release assays (QuantiFERON-TB assay [QFT] and QuantiFERON-TB Gold assay [QFT-G]) and to identify factors associated with test discordance. Methods. A cross-sectional comparison study was performed in which 856 US Navy recruits were tested for M. tuberculosis infection using the TST, QFT, and QFT-G. Results. Among the study subjects, 5.1% of TSTs resulted in an induration ⩾10 mm, and 2.9% of TSTs resulted in an induration ⩾15 mm. Eleven percent of QFT results and 0.6% of QFT-G results were positive. Assuming recruits at low risk for M. tuberculosis exposure were not infected, estimates of TST specificity were 99.1% (95% confidence interval [CI], 98.3%–99.9%) when a 15-mm cutoff value was used and 98.4% (95% CI, 97.3%–99.4%) when a 10-mm cutoff value was used. The estimated QFT specificity was 92.3% (95% CI, 90.0%–94.5%), and the estimated QFT-G specificity was 99.8% (95% CI, 99.5%–100%). Recruits who were born in countries with a high prevalence of TB were 26–40 times more likely to have discordant results involving a positive TST result and a negative QFT-G result than were recruits born in countries with a low prevalence of TB. Nineteen (50%) of 38 recruits with this type of discordant results had a TST induration ⩾15 mm. Conclusions. The QFT-G and TST are more specific than the QFT. No statistically significant difference in specificity between the QFT-G and TST was found using a 15-mm induration cutoff value. The discordant results observed among recruits with increased risk of M. tuberculosis infection may have been because of lower TST specificity or lower QFT-G sensitivity. Negative QFT-G results for recruits born in countries where TB is highly prevalent and whose TST induration was ⩾15 mm suggest that the QFT-G may be less sensitive than the TST. Additional studies are needed to determine the risk of TB when TST and QFT-G results are discordant.Keywords
This publication has 26 references indexed in Scilit:
- Routine Hospital Use of a New Commercial Whole Blood Interferon-γ Assay for the Diagnosis of Tuberculosis InfectionAmerican Journal of Respiratory and Critical Care Medicine, 2005
- Comparison of Tuberculin Skin Test and New Specific Blood Test in Tuberculosis ContactsAmerican Journal of Respiratory and Critical Care Medicine, 2004
- Comparison of a Whole-Blood Interferon γ Assay With Tuberculin Skin Testing for Detecting Latent Mycobacterium tuberculosis InfectionJAMA, 2001
- Antigenic Equivalence of Human T-Cell Responses to Mycobacterium tuberculosis -Specific RD1-Encoded Protein Antigens ESAT-6 and Culture Filtrate Protein 10 and to Mixtures of Synthetic PeptidesInfection and Immunity, 2000
- Detection of Active Tuberculosis Infection by T Cell Responses to Early‐Secreted Antigenic Target 6‐kDa Protein and Culture Filtrate Protein 10The Journal of Infectious Diseases, 2000
- Diagnostic Standards and Classification of Tuberculosis in Adults and ChildrenAmerican Journal of Respiratory and Critical Care Medicine, 2000
- Human T Cell Responses to the ESAT‐6 Antigen fromMycobacterium tuberculosisThe Journal of Infectious Diseases, 1999
- Differential T cell responses toMycobacterium tuberculosis ESAT6 in tuberculosis patients and healthy donorsEuropean Journal of Immunology, 1998
- A sandwich enzyme immunoassay for bovine interferon‐γ and its use for the detection of tuberculosis in cattleAustralian Veterinary Journal, 1990
- The Byrd StudyArchives of environmental health, 1968