title: Performance of three LED-based fluorescence microscopy systems for detection of tuberculosis in Uganda.
abstract: BACKGROUND
  Direct smear microscopy using Ziehl-Neelsen (ZN) staining is the mainstay of tuberculosis (TB) diagnosis in most high burden countries, but is limited by low sensitivity in routine practice, particularly in high human immunodeficiency virus (HIV) prevalence settings.
  
  
  METHODS
  We compared the performance of three commercial light emitting diode (LED)-based microscopy systems (Primostar™ iLED, Lumin™ and AFTER®) for fluorescent detection of Mycobacterium tuberculosis with ZN microscopy on slides prepared from sputum of TB suspects. Examination time for LED-based fluorescent microscopy (LED FM) and ZN slides was also compared, and a qualitative user appraisal of the LED FM systems was carried out.
  
  
  RESULTS
  LED FM was between 5.6 and 9.4% more sensitive than ZN microscopy, although the difference was not statistically significant. There was no significant difference in the sensitivity or specificity of the three LED FM systems, although the specificity of Fraen AFTER was somewhat lower than the other LED FM methods. Examination time for LED FM was 2 and 4 times less than for ZN microscopy. LED FM was highly acceptable to Ugandan technologists, although differences in operational performance of the three systems were reported.
  
  
  CONCLUSIONS
  LED FM compares favourably with ZN microscopy, with equivalent specificity and a modest increase in sensitivity. Screening of slides was substantially quicker using LED FM than ZN, and LED FM was rated highly by laboratory technologists. Available commercial systems have different operational characteristics which should be considered prior to programmatic implementation.
authors.affiliation: Tuberculosis Research Laboratory, Foundation for Innovative New Diagnostics, Kampala, Uganda. heidi.albert@finddiagnostics.org
authors.forename: Heidi
authors.initials: H
authors.lastname: Albert
authors.forename: Yukari
authors.initials: Y
authors.lastname: Manabe
authors.forename: George
authors.initials: G
authors.lastname: Lukyamuzi
authors.forename: Patrick
authors.initials: P
authors.lastname: Ademun
authors.forename: Sheena
authors.initials: S
authors.lastname: Mukkada
authors.forename: Barnabas
authors.initials: B
authors.lastname: Nyesiga
authors.forename: Moses
authors.initials: M
authors.lastname: Joloba
authors.forename: C N
authors.initials: CN
authors.lastname: Paramasivan
authors.forename: Mark D
authors.initials: MD
authors.lastname: Perkins
mesh_terms: D005189:False Positive Reactions; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008027:Light; D008856:Microscopy, Fluorescence / Q000295:instrumentation* / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000378:metabolism; D015588:Observer Variation; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D013183:Sputum / Q000378:metabolism; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D014454:Uganda
chemical_list: D011933:Reagent Kits, Diagnostic