title: Integrated strategies to optimize sputum smear microscopy: a prospective observational study.
abstract: BACKGROUND
  Smear-positive tuberculosis (TB) case detection rates are far below targets in most low-income countries. The standard approach to smear microscopy involves sputum collection over multiple days and examination of sputum smears by light microscopy (LM), an insensitive and time-consuming technique.
  
  
  OBJECTIVE
  To determine whether two alternative approaches can increase smear-positive case detection by increasing the efficiency (single-specimen microscopy) or sensitivity (light-emitting diode [LED] fluorescence microscopy [FM]) of TB suspect evaluation.
  
  
  METHODS
  We enrolled patients with cough of 2 weeks or more admitted to Mulago Hospital in Kampala, Uganda and collected spot and early morning sputum specimens. We compared the diagnostic accuracy of four prespecified strategies based on the number of sputum specimens collected (one specimen versus two specimens) and the type of microscopy (LM versus LED FM) using mycobacterial culture as a reference standard.
  
  
  RESULTS
  Two hundred thirty-three of 464 (50%) patients had culture-positive TB. There was no difference in sensitivity between single-specimen and two-specimen strategies when smears were examined with LM (55 vs. 56%; difference, -1%; 95% confidence interval [CI], -5 to +2%) or LED FM (61 vs. 64%; difference, -3%; 95% CI, -7 to +1%). LED FM was more sensitive than LM with both the single-specimen (61 vs. 55%; difference, 6%; 95% CI, 2-10%) and two-specimen strategies (64 vs. 56%; difference, 8%; 95% CI, 3-12%). Findings were similar among the HIV-infected patient subset (n = 321 patients).
  
  
  CONCLUSIONS
  In low-income, high TB burden settings, single-specimen microscopy and LED FM, either alone or in combination, could considerably increase identification of smear-positive TB cases.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA. acattamanchi@medsfgh.ucsf.edu
authors.forename: Adithya
authors.initials: A
authors.lastname: Cattamanchi
authors.forename: Laurence
authors.initials: L
authors.lastname: Huang
authors.forename: William
authors.initials: W
authors.lastname: Worodria
authors.forename: Saskia
authors.initials: S
authors.lastname: den Boon
authors.forename: Nelson
authors.initials: N
authors.lastname: Kalema
authors.forename: Winceslaus
authors.initials: W
authors.lastname: Katagira
authors.forename: Patrick
authors.initials: P
authors.lastname: Byanyima
authors.forename: Samuel
authors.initials: S
authors.lastname: Yoo
authors.forename: John
authors.initials: J
authors.lastname: Matovu
authors.forename: Philip C
authors.initials: PC
authors.lastname: Hopewell
authors.forename: J Lucian
authors.initials: JL
authors.lastname: Davis
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods; D008859:Microscopy, Polarization / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology*; D014454:Uganda