The role of a whole blood interferon-gamma assay for the detection of latent tuberculosis infection in Bacille Calmette-Guérin vaccinated children

Diagn Microbiol Infect Dis. 2008 Dec;62(4):389-94. doi: 10.1016/j.diagmicrobio.2008.08.022. Epub 2008 Nov 5.


The tuberculin skin test (TST) has limitations in children who are under the Bacille Calmette-Guérin (BCG) effect. Our aim was to evaluate the QuantiFERON-TB Gold In-Tube (QFT-G IT) blood test for Mycobacterium tuberculosis infection in children and to compare results with those of the TST. QFT-G IT and TST data were collected from 227 children between 0 and 15 years of age, split into 4 risk groups. Forty-two children were close contacts, 29 were casual contacts, and 65 were controls. The QFT-G IT positivity rates were 19% (8/42), 6.9% (2/29), and 1.5% (1/65), with a significantly higher rate for the close contacts over the controls (P < 0.05). The high specificity of the QFT-G IT assay and the association of positive results with increasing risk of infection in our study suggest it has major benefits over the TST as a screening test for latent infection with M. tuberculosis in BCG-vaccinated children.

MeSH terms

  • BCG Vaccine / immunology*
  • Child, Preschool
  • Contact Tracing
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Interferon-gamma / blood*
  • Male
  • Tuberculosis / blood
  • Tuberculosis / diagnosis*
  • Tuberculosis / epidemiology


  • BCG Vaccine
  • Interferon-gamma