title: Comparison among three cold staining methods in the primary diagnosis of tuberculosis: a pilot study.
abstract: OBJECTIVE
  In developing countries, sputum smear microscopy is the main tool for pulmonary tuberculosis case finding. The objective of the present study was to evaluate the diagnostic efficacy of Gabbett's staining (GS) and modified cold staining (MCS), both of which are two-step methods, in comparison with that of fluorescent staining (FS), which is a three-step method, for the detection of AFB in sputum smears.
  
  
  METHODS
  Our sample comprised 260 sputum samples collected from individuals suspected of having pulmonary tuberculosis at Kasturba Hospital, in Manipal, India. Smears were prepared in triplicate: one each for FS, MCS, and GS. The smears were randomly numbered so that the examiner was blinded to the sample identities.
  
  
  RESULTS
  Of the 260 samples, 16 (6.15%), 15 (5.77%), and 13 (5.00%) showed positive AFB results with FS, MCS, and GS, respectively. The sensitivity of GS and MCS, in comparison with that of FS, was 81.25% and 93.75%, respectively. The concordance of GS and MCS with FS was good (0.988 and 0.996, respectively), and no statistically significant differences were found.
  
  
  CONCLUSIONS
  Although MCS and GS were found to be less sensitive than was FS, which is evaluated under fluorescence microscopy, the first two are promising methods for the diagnosis of tuberculosis.
authors.affiliation: Department of Microbiology, St. John's Medical College, Bangalore, India. soham.micro@gmail.com
authors.forename: Soham
authors.initials: S
authors.lastname: Gupta
authors.forename: Vishnu Prasad
authors.initials: VP
authors.lastname: Shenoy
authors.forename: Indira
authors.initials: I
authors.lastname: Bairy
authors.forename: Sethumadhavan
authors.initials: S
authors.lastname: Muralidharan
mesh_terms: D001431:Bacteriological Techniques; D004396:Coloring Agents; D006801:Humans; D008856:Microscopy, Fluorescence; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011897:Random Allocation; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D013194:Staining and Labeling / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
chemical_list: D004396:Coloring Agents