Impact of sputum quality and quantity on smear and culture positivity: findings from a tuberculosis prevalence study in central India

Abstract

The objective of this study was to assess the impact of sputum quality and quantity on smear and culture positivity for Mycobacterium tuberculosis. A total of 14 708 sputum specimens, collected from respiratory symptomatics in a TB prevalence survey, were evaluated for gross appearance and volume of sputum and examined by smear microscopy and culture. The smear and culture positivity increased with the quantity and the up gradation in quality of sputum, and the difference was significant. The study highlights the importance of visual screening of sputum specimens in the detection of pulmonary TB particularly in resource limited settings.