title: Simple measures are as effective as invasive techniques in the diagnosis of pulmonary tuberculosis in Malawi.
abstract: METHODS
  Detection of smear-positive pulmonary tuberculosis (PTB) cases is vital for tuberculosis (TB) control. Methods to augment sputum collection are available, but their additional benefit is uncertain in resource-limited settings.
  
  
  OBJECTIVE
  To compare the diagnostic yields using five methods to obtain sputum from adults diagnosed with smear-negative PTB in Malawi.
  
  
  METHODS
  Self-expectorated sputum was collected under supervision for microscopy and mycobacterial culture in the study laboratory. Confirmed smear-negative patients provided physiotherapy-assisted sputum and induced sputum, followed the next morning by gastric washing and bronchoalveolar lavage (BAL) samples.
  
  
  RESULTS
  A total of 150 patients diagnosed with smear-negative PTB by the hospital service were screened; 39 (26%) were smear-positive from supervised self-expectorated sputum examined in the study laboratory. The remaining 111 confirmed smear-negative patients were enrolled in the study; 89% were human immunodeficiency virus positive. Seven additional smear-positive cases were diagnosed using the augmented sputum collection techniques. No differences were observed in the numbers of cases detected using the different methods. Of the 46 smear-positive cases, 44 (95.6%) could be detected from self-expectorated and physiotherapy-assisted samples.
  
  
  CONCLUSIONS
  For countries such as Malawi, the best use of limited resources to detect smear-positive PTB cases would be to improve the quality of self-expectorated sputum collection and microscopy. The additional diagnostic yield using BAL after induced sputum is limited.
authors.affiliation: Tropical and Infectious Diseases Unit, Royal Liverpool University Hospital, Liverpool, UK. belldavidj@gmail.com
authors.forename: D J
authors.initials: DJ
authors.lastname: Bell
authors.forename: R
authors.initials: R
authors.lastname: Dacombe
authors.forename: S M
authors.initials: SM
authors.lastname: Graham
authors.forename: A
authors.initials: A
authors.lastname: Hicks
authors.forename: D
authors.initials: D
authors.lastname: Cohen
authors.forename: T
authors.initials: T
authors.lastname: Chikaonda
authors.forename: N
authors.initials: N
authors.lastname: French
authors.forename: M E
authors.initials: ME
authors.lastname: Molyneux
authors.forename: E E
authors.initials: EE
authors.lastname: Zijlstra
authors.forename: S B
authors.initials: SB
authors.lastname: Squire
authors.forename: S B
authors.initials: SB
authors.lastname: Gordon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D005260:Female; D006801:Humans; D008295:Malawi; D008297:Male; D008875:Middle Aged; D013048:Specimen Handling / Q000379:methods*; D013183:Sputum / Q000382:microbiology*; D013270:Stomach / Q000382:microbiology; D007507:Therapeutic Irrigation; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D055815:Young Adult