title: Comparison of LED and conventional fluorescence microscopy for detection of acid fast bacilli in a low-incidence setting.
abstract: BACKGROUND
  Light emitting diode fluorescence microscopes have many practical advantages over conventional mercury vapour fluorescence microscopes, which would make them the preferred choice for laboratories in both low- and high-resource settings, provided performance is equivalent.
  
  
  METHODS
  In a nested case-control study, we compared diagnostic accuracy and time required to read slides with the Zeiss PrimoStar iLED, LW Scientific Lumin, and a conventional fluorescence microscope (Leica DMLS). Mycobacterial culture was used as the reference standard, and subgroup analysis by specimen source and organism isolated were performed.
  
  
  RESULTS
  There was no difference in sensitivity or specificity between the three microscopes, and agreement was high for all comparisons and subgroups. The Lumin and the conventional fluorescence microscope were equivalent with respect to time required to read smears, but the Zeiss iLED was significantly time saving compared to both.
  
  
  CONCLUSIONS
  Light emitting diode microscopy should be considered by all tuberculosis diagnostic laboratories, including those in high income countries, as a replacement for conventional fluorescence microscopes. Our findings provide support to the recent World Health Organization policy recommending that conventional fluorescence microscopy be replaced by light emitting diode microscopy using auramine staining in all settings where fluorescence microscopy is currently used.
authors.affiliation: Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
authors.forename: Jessica
authors.initials: J
authors.lastname: Minion
authors.forename: Madhukar
authors.initials: M
authors.lastname: Pai
authors.forename: Andrew
authors.initials: A
authors.lastname: Ramsay
authors.forename: Dick
authors.initials: D
authors.lastname: Menzies
authors.forename: Christina
authors.initials: C
authors.lastname: Greenaway
mesh_terms: D000143:Acids / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D008856:Microscopy, Fluorescence / Q000295:instrumentation* / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013045:Species Specificity
chemical_list: D000143:Acids