title: Post-bronchoscopy sputum: improving the diagnostic yield in smear negative pulmonary TB.
abstract: BACKGROUND
  Patients with suspected active Pulmonary Tuberculosis (PTB) who are Acid-Fast Bacilli (AFB) smear negative or non-productive of sputum may undergo bronchoalveolar lavage. However, post-bronchoscopy sputum (PBS) sampling is not routine. The aim of this study was to establish the potential diagnostic value of PBS sampling.
  
  
  METHODS
  A retrospective study of patients attending a London University hospital with microbiologically confirmed PTB between January 2004 and December 2010. Patients who were AFB smear negative or non-productive of sputum were eligible if sputum sampling was performed within 7 days of bronchoscopy.
  
  
  RESULTS
  Over the study period, 236 patients had microbiologically confirmed smear negative PTB of which 57 patients were eligible for the study. 15 patients (26.3%) were infected with HIV. 19 patients (33.3%) converted to AFB sputum smear positivity post-bronchoscopy and 5 patients (8.8%) were exclusively AFB sputum smear positive on PBS microscopy. Mycobacterium tuberculosis was cultured from the PBS of 43 patients (75.4%) and of these, 4 (7.0%) were exclusively PBS culture positive.
  
  
  CONCLUSIONS
  PBS analysis can provide a simple method of rapidly diagnosing pulmonary tuberculosis. In this cohort, M. tuberculosis culture yield was increased by 7% through PBS sampling. This study has important infection control implications with nearly one third of patients becoming more infectious after bronchoscopy.
authors.affiliation: Chest and Allergy Department, St Mary's Hospital, Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, UK. petergeorge@doctors.net.uk
authors.forename: Peter M
authors.initials: PM
authors.lastname: George
authors.forename: Meera
authors.initials: M
authors.lastname: Mehta
authors.forename: Jaideep
authors.initials: J
authors.lastname: Dhariwal
authors.forename: Aran
authors.initials: A
authors.lastname: Singanayagam
authors.forename: Claire E
authors.initials: CE
authors.lastname: Raphael
authors.forename: Mohammad
authors.initials: M
authors.lastname: Salmasi
authors.forename: David W
authors.initials: DW
authors.lastname: Connell
authors.forename: Philip
authors.initials: P
authors.lastname: Molyneaux
authors.forename: Melissa
authors.initials: M
authors.lastname: Wickremasinghe
authors.forename: Annette
authors.initials: A
authors.lastname: Jepson
authors.forename: Onn Min
authors.initials: OM
authors.lastname: Kon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D001999:Bronchoscopy; D005260:Female; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D055815:Young Adult