title: An operational study comparing microscopes and staining variations for tuberculosis LED FM.
abstract: METHODS
  Tuberculosis control projects, Damien Foundation Bangladesh.
  
  
  OBJECTIVE
  To compare transmitted fluorescence (Olympus CX21™/FRAEN FluoLED™) with epi-fluorescence (Zeiss Primostar iLED™) light-emitting diode microscopes (LED-FM) and various auramine staining and destaining/counterstaining techniques for the detection of acid-fast bacilli.
  
  
  METHODS
  Multicentre blinded reading of routine smears on both types of microscopes using different staining techniques in multiple phases. LED-FM rechecking of discordant series with and without restaining to calculate operating characteristics.
  
  
  RESULTS
  Among 64 874 smears, both instruments detected 9.6% positives. Compared to the standard technique, the stronger auramine-O formulation did not perform better. Thiazine red counterstaining tended to yield more false-positive as well as false-negative errors. Combined destaining/counterstaining (sensitivity 93%, positive predictive value [PPV] 98%) proved significantly less effective. Both destaining with 1% hydrochloric acid (HCl) and 10% alcohol and the standard 0.5% HCl and 70-95% alcohol were equally accurate (sensitivity 95-96%, PPV 99%). The sturdiness of the microscopes in field conditions was sub-optimal: only 5/16 instruments did not break down.
  
  
  CONCLUSIONS
  Both microscopes performed equally well. The standard staining technique is as good as the more complicated and expensive variations. A destaining solution containing only 10% alcohol works perfectly well. The inferior quality of LED-FM microscope components is an obstacle to FM expansion.
authors.affiliation: <label>*</label>International Union Against Tuberculosis and Lung Disease, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Van Deun
authors.affiliation: <label><sup>‡</sup></label>Damien Foundation Bangladesh, Dhaka, Bangladesh.
authors.forename: K J M
authors.initials: KJ
authors.lastname: Aung
authors.affiliation: <label><sup>‡</sup></label>Damien Foundation Bangladesh, Dhaka, Bangladesh.
authors.forename: M H
authors.initials: MH
authors.lastname: Khan
authors.affiliation: <label><sup>†</sup></label>Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: B C
authors.initials: BC
authors.lastname: de Jong
authors.affiliation: <label><sup>†</sup></label>Mycobacteriology Unit, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Gumusboga
authors.affiliation: <label><sup>‡</sup></label>Damien Foundation Bangladesh, Dhaka, Bangladesh.
authors.forename: M A
authors.initials: MA
authors.lastname: Hossain
mesh_terms: D001576:Benzophenoneidum / Q000737:chemistry; D005188:False Negative Reactions; D005189:False Positive Reactions; D008856:Microscopy, Fluorescence / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D013194:Staining and Labeling; D014376:Tuberculosis / Q000175:diagnosis*
chemical_list: D009930:Organic Chemicals; C419142:thiazin red; D001576:Benzophenoneidum