title: Added value of interferon-gamma release assays in screening for tuberculous infection in the Netherlands.
abstract: BACKGROUND
  Interferon-gamma release assays (IGRAs) are reported to be more specific for the diagnosis of latent tuberculous infection (LTBI) than the tuberculin skin test (TST). The two-step procedure, TST followed by an IGRA, is reported to be cost-effective in high-income countries, but it requires more financial resources.
  
  
  OBJECTIVE
  To assess the added value of IGRA compared to TST alone in the Netherlands.
  
  
  METHODS
  Test results and background data on persons tested with an IGRA were recorded by the Public Municipal Health Services in a web-based database. The number of persons diagnosed with LTBI using different screening algorithms was calculated.
  
  
  RESULTS
  In those tested with an IGRA, at least 60% of persons who would have been diagnosed with LTBI based on TST alone had a negative IGRA. Among those with a TST reaction below the cut-off for the diagnosis of LTBI, 13% had a positive IGRA. For 41% of persons tested with an IGRA after TST, the IGRA influenced whether or not an LTBI diagnosis would be made.
  
  
  CONCLUSIONS
  With the IGRA as reference standard, a high proportion of persons in low-prevalence settings are treated unnecessarily for LTBI if tested with TST alone, while a small proportion eligible for preventive treatment are missed. Incremental costs of the two-step strategy seem to be balanced by the improved targeting of preventive treatment.
authors.affiliation: KNCV Tuberculosis Foundation, The Hague, The Netherlands.
authors.forename: C G M
authors.initials: CG
authors.lastname: Erkens
authors.affiliation: KNCV Tuberculosis Foundation, The Hague, The Netherlands.
authors.forename: A G
authors.initials: AG
authors.lastname: Dinmohamed
authors.affiliation: Public Health Service Rotterdam Rijnmond, Rotterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kamphorst
authors.affiliation: GGD Twente, Enschede, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Toumanian
authors.affiliation: GGD Brabant Zuidoost, Eindhoven, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: van Nispen-Dobrescu
authors.affiliation: GGD Zuid Limburg, Heerlen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Alink
authors.affiliation: GGD Den Haag, Den Haag, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Oudshoorn
authors.affiliation: Public Health Services Amsterdam, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Mensen
authors.affiliation: KNCV Tuberculosis Foundation, The Hague, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: van den Hof
authors.affiliation: Public Health Services Amsterdam, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Borgdorff
authors.affiliation: KNCV Tuberculosis Foundation, The Hague, The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Verver
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D017048:Health Care Costs; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000191:economics; D055985:Latent Tuberculosis / Q000175:diagnosis* / Q000188:drug therapy / Q000191:economics / Q000276:immunology / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000472:pathogenicity*; D009426:Netherlands; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014374:Tuberculin Test / Q000191:economics; D019564:Unnecessary Procedures; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents