title: Evaluation of an interferon-gamma release assay in young contacts of active tuberculosis cases.
abstract: In a cross-sectional study in a hospital in Tehran in 2006-08 the QuantiFERON-TB interferon-gamma release assay (QTB) was compared with the tuberculin skin test (TST) in 59 young people (aged < 20 years) with close contact with immunocompetent cases of proven pulmonary tuberculosis. After 1 year follow-up 10 subjects had progressed to tuberculosis disease and received treatment; TSTwas positive in 30% and QTB in 100%. Of the 49 non-progressive subjects, TST was positive in 10.4% and QTB in 16.3%. The agreement between TST and QTB assay in non-progressive subjects was poor (K = 0.43). False positive and false negative rates for TST were 40.0% and 9.3% respectively; positive and predictive values were 60.0% and 90.7%. We suggest adding the interferon assay to the skin test in the decision to perform chest X-ray or to start chemoprophylaxis at least in younger subjects (aged < 20 years).
authors.affiliation: Research Centre of Paediatric Infectious Diseases, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran. samileh_noorbakhsh@yahoo.com
authors.forename: S
authors.initials: S
authors.lastname: Noorbakhsh
authors.forename: J
authors.initials: J
authors.lastname: Mousavi
authors.forename: M
authors.initials: M
authors.lastname: Barati
authors.forename: A R
authors.initials: AR
authors.lastname: Shamshiri
authors.forename: M
authors.initials: M
authors.lastname: Shekarabi
authors.forename: A
authors.initials: A
authors.lastname: Tabatabaei
authors.forename: G
authors.initials: G
authors.lastname: Soleimani
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests; D007492:Iran / Q000453:epidemiology; D008297:Male; D011237:Predictive Value of Tests; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000635:transmission