title: No added value of performing Ziehl-Neelsen on auramine-positive samples for tuberculosis diagnostics.
abstract: METHODS
  Regional Laboratory for Tuberculosis, Amsterdam, The Netherlands.
  
  
  BACKGROUND
  There is a push to switch from Ziehl-Neelsen (ZN) to auramine microscopy. Despite World Health Organization guidelines that one staining method is sufficient, in some countries national guidelines prescribe that auramine-positive samples should be confirmed by ZN.
  
  
  OBJECTIVE
  To investigate the added value of confirming auramine-positive samples using ZN.
  
  
  METHODS
  Using diagnostic data from 10 276 respiratory samples collected from 5525 patients tested for tuberculosis (TB) at the Municipal Health Service of Amsterdam between May 2006 and October 2011, we determined the diagnostic accuracy of auramine alone and of confirmation of auramine-positive samples using ZN.
  
  
  RESULTS
  Of 141 M. tuberculosis complex-positive samples detected using auramine on which ZN was performed, 32 (22.7%) were ZN-negative. A similar percentage (6/25, 24.0%) of negatives was found for samples containing non-tuberculous mycobacteria (NTM) species, thus making it impossible to distinguish between TB and NTM on the basis of ZN results.
  
  
  CONCLUSIONS
  A positive auramine result followed by a negative ZN result could not be used to exclude TB or to indicate the presence of NTM species. Confirming auramine-positive samples using ZN in this setting thus provided no clinically informative information and was a waste of resources.
authors.affiliation: Royal Tropical Institute, KIT, KIT Biomedical Research, Amsterdam, The Netherlands. r.anthony@kit.nl
authors.forename: A L
authors.initials: AL
authors.lastname: den Hertog
authors.forename: S
authors.initials: S
authors.lastname: Daher
authors.forename: M
authors.initials: M
authors.lastname: Straetemans
authors.forename: M
authors.initials: M
authors.lastname: Scholing
authors.forename: R M
authors.initials: RM
authors.lastname: Anthony
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001576:Benzophenoneidum; D002648:Child; D002675:Child, Preschool; D004396:Coloring Agents; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D009426:Netherlands / Q000453:epidemiology; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology; D013194:Staining and Labeling / Q000379:methods*; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D001576:Benzophenoneidum