title: Same-day sputum smear microscopy for the diagnosis of pulmonary tuberculosis: direct vs. concentrated smear.
abstract: OBJECTIVE
  To evaluate the efficacy of sputum microscopy by the concentration method using spot and morning and same-day smears for the diagnosis of pulmonary tuberculosis.
  
  
  METHODS
  Three sputum specimens (spot, second spot and morning) were collected from study participants. Three smears were prepared from the direct sample and three using the N-acetyl-l-cysteine-sodium hydroxide concentration method. The smears were stained using Ziehl-Neelsen (ZN) staining, modified ZN (MZN) staining and fluorescent staining (FS). Smear results were pooled and compared in two categories: standard spot and morning, and same-day smears. The χ(2) test was used to evaluate the statistical difference in smear-positive cases.
  
  
  RESULTS
  Among 3186 participants included in the study, smear positivity was respectively 9.6%, 9.8% and 10.8% for ZN, MZN and FS smears using spot and morning smears. Using same-day smears, smear positivity was respectively 9.5%, 9.8% and 10.6% for ZN, MZN and FS smears. Smear positivity increased to 16% with the concentration method.
  
  
  CONCLUSIONS
  Nil dropouts and patient convenience are the added advantages of using same-day smears, and the concentration method improved smear positivity. Given these advantages, using same-day smears with the concentration method should be considered by the World Health Organization and India's Revised National Tuberculosis Control Programme.
authors.affiliation: Department of Microbiology, GSL Medical College, Rajahmundry, India.
authors.forename: T J
authors.initials: TJ
authors.lastname: Chandra
authors.affiliation: Centre for Laboratory Animal Technology and Research, Sathyabama University, Chennai, India.
authors.forename: R
authors.initials: R
authors.lastname: Selvaraj
authors.affiliation: Department of Pathology, GSL Medical College, Rajahmundry, India.
authors.forename: Y V
authors.initials: YV
authors.lastname: Sharma
mesh_terms: D000328:Adult; D001431:Bacteriological Techniques; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008856:Microscopy, Fluorescence; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000382:microbiology; D013194:Staining and Labeling; D013997:Time Factors; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology; D057188:Workflow