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

Background: The objective of this study was to assess the impact of sputum quality and quantity on smear and culture positivity for Mycobacterium tuberculosis.

Methods: 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.

Results: The smear and culture positivity increased with the quantity and the up gradation in quality of sputum, and the difference was significant.

Conclusion: The study highlights the importance of visual screening of sputum specimens in the detection of pulmonary TB particularly in resource limited settings.