title: The use of an interferon-gamma release assay to screen for pediatric latent tuberculosis infection in the eastern region of the Emirate of Abu Dhabi.
abstract: OBJECTIVE
  Intense migration to the United Arab Emirates from tuberculosis (TB) high-endemic areas presents a particular risk to the population. Screening for latent tuberculosis infection (LTBI) usually involves risk assessment, the tuberculin skin test (TST), and interferon-gamma release assay (IGRA). This study investigated the use of an IGRA to screen for LTBI and compared its performance with a risk assessment questionnaire.
  
  
  METHODS
  This prospective cross-sectional study was conducted at seven Ambulatory Healthcare Services facilities in Abu Dhabi. Participants (88% Emiratis) were pediatric patients presenting for routine care. The QuantiFERON-TB Gold In-Tube test was performed and the parents completed a questionnaire assessing TB risk factors.
  
  
  RESULTS
  Six-hundred and ninety-nine subjects (median age 8.7 years, interquartile range 9.2 years) were enrolled; 669 (96%) agreed to testing. Four patients had a positive IGRA; one had previously been treated for TB, resulting in three patients with LTBI. The estimated LTBI prevalence was 0.45% (95% confidence interval 0.09-1.3). A household contact from a TB high-endemic area was reported in 44%, travel to a TB high-endemic area in 10%, and contact with someone with a chronic cough in 7%, a TB case in 3%, a TST-positive case in 2%, and an IGRA-positive case in 2%. Fifty percent of participants had at least one risk factor. The risk assessment did not predict a positive IGRA.
  
  
  CONCLUSIONS
  The questionnaire yielded a risk of TB exposure of 50%, however the LTBI prevalence, as defined by the IGRA, was low (0.45%).
authors.affiliation: Ambulatory Healthcare Services, Al-Ain, United Arab Emirates.
authors.forename: Lolowa A
authors.initials: LA
authors.lastname: Al Mekaini
authors.affiliation: Ambulatory Healthcare Services, Al-Ain, United Arab Emirates.
authors.forename: Omar N
authors.initials: ON
authors.lastname: Al Jabri
authors.affiliation: Department of Pediatrics, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors.forename: Hassib
authors.initials: H
authors.lastname: Narchi
authors.affiliation: Ambulatory Healthcare Services, Al-Ain, United Arab Emirates.
authors.forename: Salwa M
authors.initials: SM
authors.lastname: Kamal
authors.affiliation: Ambulatory Healthcare Services, Al-Ain, United Arab Emirates.
authors.forename: Abdelazim
authors.initials: A
authors.lastname: Mabrook
authors.affiliation: Ambulatory Healthcare Services, Al-Ain, United Arab Emirates.
authors.forename: Mariam M
authors.initials: MM
authors.lastname: Al Kuwaiti
authors.affiliation: Institute of Public Health, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors.forename: Mohamud M
authors.initials: MM
authors.lastname: Sheek-Hussein
authors.affiliation: Department of Pediatrics, United Arab Emirates University, Al-Ain, United Arab Emirates.
authors.forename: Abdul-Kader
authors.initials: AK
authors.lastname: Souid
authors.affiliation: Department of Pediatrics, United Arab Emirates University, Al-Ain, United Arab Emirates. Electronic address: alsuwaidia@uaeu.ac.ae.
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: Alsuwaidi
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D059425:Interferon-gamma Release Tests / Q000379:methods*; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008403:Mass Screening / Q000379:methods; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014374:Tuberculin Test / Q000379:methods; D014479:United Arab Emirates / Q000453:epidemiology
keywords: IGRA; Interferon-gamma release assay; LTBI; Pediatric latent tuberculosis infection; TB risk assessment; UAE