title: Pre-employment screening of latent tuberculosis infection among healthcare workers using tuberculin skin test and QuantiFERON-TB Gold test at a tertiary care hospital in Saudi Arabia.
abstract: OBJECTIVE
  To assess the agreement between the tuberculin skin test (TST) and the QuantiFERON-TB Gold test (QFT-G) as pre-employment screening tests for latent tuberculosis infection (LTBI) among healthcare workers.
  
  
  METHODS
  A retrospective cross-sectional study was conducted among 1412 healthcare workers who were screened for LTBI during the period from August 2009 to May 2011 at a tertiary-care hospital in the Kingdom of Saudi Arabia (KSA). The studied population was screened for LTBI using both TST and QFT-G simultaneously. The agreement between both tests was quantified using the Kappa coefficient (κ).
  
  
  RESULTS
  Comparing the results of QFT-G with TST, the tests had a significant overall agreement of 73.7% (1040/1412; κ=0.33; p<0.01). Negative concordance comprised 60.1% of the results, and positive concordance comprised 13.5%. However, positive TST but negative QFT comprised 16.3% of the results, and negative TST but positive QFT-G comprised 10.1%. Concordance was significantly associated with young age, female gender, Saudi-born nationals, and early career but not job type (clinical versus non-clinical) nor status of Bacillus Calmette-Guerin (BCG) vaccination.
  
  
  CONCLUSIONS
  This study demonstrated 73.7% overall agreement between TST and QFT-G results among healthcare workers during pre-employment screening for LTBI. The results need to be confirmed in future studies before recommending QFT-G as a pre-employment screening test for LTBI.
authors.affiliation: Infection Prevention and Control Department, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia; Community Medicine Department, Faculty of Medicine, Mansoura University, Egypt. Electronic address: mhelaly72@gmail.com.
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Helaly
authors.affiliation: Infection Prevention and Control Department, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Waseem
authors.initials: W
authors.lastname: Khan
authors.affiliation: Infection Prevention and Control Department, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia; Community Medicine Department, Faculty of Medicine, Mansoura University, Egypt.
authors.forename: Aiman
authors.initials: A
authors.lastname: El-Saed
authors.affiliation: Infection Prevention and Control Department, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia; King Saud Bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Kingdom of Saudi Arabia; King Abdullah International Medical Research Center, National Guard Health Affairs, Kingdom of Saudi Arabia.
authors.forename: Hanan H
authors.initials: HH
authors.lastname: Balkhy
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004651:Employment; D005260:Female; D006282:Health Personnel; D006801:Humans; D059425:Interferon-gamma Release Tests; D055985:Latent Tuberculosis / Q000175:diagnosis*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D012189:Retrospective Studies; D012529:Saudi Arabia; D062606:Tertiary Care Centers; D014374:Tuberculin Test; D055815:Young Adult
keywords: Healthcare workers; Latent tuberculosis infection; QuantiFERON-TB Gold test; Tuberculin skin test