title: Yield of two consecutive sputum specimens for the effective diagnosis of pulmonary tuberculosis.
abstract: BACKGROUND
  From long instances, it is debatable whether three sputum specimens are required for the diagnosis of pulmonary tuberculosis (TB) or TB can be diagnosed effectively using two consecutive sputum specimens. This study was set out to evaluate the significance of examining multiple sputum specimens in diagnosis of TB.
  
  
  METHODS
  We retrospectively reviewed the acid-fast bacillus (AFB) smear and culture results of three consecutive days' sputum specimens from 413 confirmed TB patients which were detected as part of a larger active case finding study in Dhaka Central Jail, the largest correctional facility in Bangladesh.
  
  
  RESULTS
  AFB was detected from 81% (n = 334) patients, of which 89% (n = 297) were diagnosed from the first and additional 9% (n = 30) were from the second sputum specimen. M. tuberculosis growth was observed for 406 patients and 85% (n = 343) were obtained from the first sputum and additional 10% (n = 42) were from the second one. The third specimen didn't show significant additional diagnostic value for the detection of AFB by microscopy or growth of the M. tuberculosis.
  
  
  CONCLUSIONS
  We concluded from our study results that examining two consecutive sputum specimens is sufficient enough for the effective diagnosis of TB. It can also decrease the laboratory workload and hence improve the quality of work in settings with high TB burden like Bangladesh.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, Bangladesh.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Islam
authors.forename: Razia
authors.initials: R
authors.lastname: Khatun
authors.forename: Mohammad Khaja Mafij
authors.initials: MK
authors.lastname: Uddin
authors.forename: Md Siddiqur Rahman
authors.initials: MS
authors.lastname: Khan
authors.forename: Md Toufiq
authors.initials: MT
authors.lastname: Rahman
authors.forename: Tahmeed
authors.initials: T
authors.lastname: Ahmed
authors.forename: Sayera
authors.initials: S
authors.lastname: Banu
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques; D001459:Bangladesh; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D011329:Prisoners; D012189:Retrospective Studies; D012923:Social Class; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology