title: Tuberculin skin test and QuantiFERON® assay in young children investigated for tuberculosis in South Africa.
abstract: METHODS
  Although the literature on interferon-gamma release assays on tuberculosis (TB) in children has increased, data pertaining to young children remain relatively limited.
  
  
  OBJECTIVE
  To compare results from the tuberculin skin test (TST) and the QuantiFERON®-TB Gold In-Tube  assay (QFT) in children aged <3 years investigated for TB disease.
  
  
  METHODS
  TB suspects were evaluated by medical history and examination, TST, QFT, chest radiography, induced sputum and gastric washings for smear and culture for Mycobacterium tuberculosis.
  
  
  RESULTS
  A total  of 400 children were enrolled. Among 397 children with both test results, 68 (17%) were QFT-positive and 72 (18%) were TST-positive (≥10 mm). Agreement between the tests was excellent (94%, κ = 0.79, 95%CI 0.69-0.89). TB disease was diagnosed in 52/397 (13%) participants:  3 definite, 35 probable and 14 possible TB. QFT sensitivity and specificity for TB disease were respectively 38% and 81%. TST sensitivity and specificity were respectively 35% and 84%.
  
  
  CONCLUSIONS
  While TST and QFT had excellent concordance in this population, both tests had much lower  sensitivity for TB disease than has been reported for other age groups. Our results suggested equivalent performance of QFT and TST in the diagnosis of TB disease in young children in a high-burden setting.
authors.affiliation: South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa. sizulu.moyo@uct.ac.za
authors.forename: S
authors.initials: S
authors.lastname: Moyo
authors.forename: F
authors.initials: F
authors.lastname: Isaacs
authors.forename: S
authors.initials: S
authors.lastname: Gelderbloem
authors.forename: S
authors.initials: S
authors.lastname: Verver
authors.forename: A J
authors.initials: AJ
authors.lastname: Hawkridge
authors.forename: M
authors.initials: M
authors.lastname: Hatherill
authors.forename: M
authors.initials: M
authors.lastname: Tameris
authors.forename: H
authors.initials: H
authors.lastname: Geldenhuys
authors.forename: L
authors.initials: L
authors.lastname: Workman
authors.forename: M
authors.initials: M
authors.lastname: Pai
authors.forename: G
authors.initials: G
authors.lastname: Hussey
authors.forename: W A
authors.initials: WA
authors.lastname: Hanekom
authors.forename: H
authors.initials: H
authors.lastname: Mahomed
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000097:blood; D059425:Interferon-gamma Release Tests / Q000379:methods*; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology* / Q000302:isolation & purification; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013019:South Africa; D013183:Sputum / Q000382:microbiology; D014374:Tuberculin Test / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
chemical_list: D007371:Interferon-gamma