Investigating the quality of expectorated sputum for tuberculosis diagnosis in Bolivia.

A low-power microscope-based cytological system to assess the quality of expectorated sputum provided for tuberculosis (TB) diagnosis was piloted in Bolivia. A total of 3688 samples were subjected to visual and cytological examination in nine laboratories: of these, 591 (16%) were misclassified by visual examination and 294 (8%) were found to be degraded. The degree of discordance varied between locations, and laboratories received a higher number of degraded specimens from isolated health clinics. Cytological assessment of sputum was found to be feasible and identified areas for improvement in the Bolivian diagnostic system for TB.