title: Comparison of QuantiFERON-TB gold in tube test versus tuberculin skin test for screening of latent tuberculosis infection in Saudi Arabia: A population-based study.
abstract: OBJECTIVE
  To compare QuantiFERON-TB gold in tube (QFT-GIT) test with tuberculin skin test (TST) in detecting latent tuberculosis infection (LTBI) among a general population in Saudi Arabia.
  
  
  METHODS
  A population-based cross-sectional study was conducted between July 2010 and March 2013 among individuals randomly selected from the list of those receiving care at primary healthcare centers in three provinces of Saudi Arabia; Central, Western, and Eastern provinces. Those younger than 5 years, immunocompromised, had a current or previous history of active TB, LTBI, or who were receiving anti-TB medications were excluded. Informed consent was obtained before the study questionnaire was completed. Participants were then evaluated for LTBI using QFT-GIT test followed immediately by TST.
  
  
  RESULTS
  Of the 1369 subjects included in the final analysis, QFT-GIT was positive in 124 (9.1%) and TST was positive in 127 (9.3%). Positive concordance was observed in 49 (3.6%) subjects while negative concordance was observed in 1167 (85.2%) subjects. The overall agreement between the two tests was 88.8% with a significant kappa (κ) test (κ = 0.332, P < 0.001). Concordance was significantly higher in younger age, female gender, single status, students, primary education, living in middle-sized families, and never smoked.
  
  
  CONCLUSIONS
  The overall agreement of TST and QFT-GIT for the detection of LTBI among a Saudi general population was 88.8%. QFT-GIT is probably comparable to TST for detecting LTBI in an intermediate TB burden country with high at birth bacille calmette guerin vaccination coverage. Further prospective studies are needed to compare the ability of both tests to predict TB disease.
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Jeddah, Saudi Arabia; Department of Infection Prevention and Control, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Hanan H
authors: HH
authors: Balkhy
authors: Department of Infection Prevention and Control, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Public Health and Community Medicine, Faculty of Medicine, Tanta University, Tanta, Egypt.
authors: Kamel
authors: K
authors: El Beltagy
authors: Department of Infection Prevention and Control, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Public Health and Community Medicine, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
authors: Aiman
authors: A
authors: El-Saed
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Preventive Medicine, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Badr
authors: B
authors: Aljasir
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Infection Prevention and Control, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Abdulhakeem
authors: A
authors: Althaqafi
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Medicine, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Adel F
authors: AF
authors: Alothman
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Mohammad
authors: M
authors: Alshalaan
authors: Department of Pediatrics, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia; Department of Medicine, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
authors: Hamdan
authors: H
authors: Al-Jahdali
keywords: Latent mycobacterium tuberculosis infection; QuantiFERON-TB gold in tube test; Saudi Arabia; tuberculin skin test