What a difference a day makes: same-day versus 2-day sputum smear microscopy for diagnosing tuberculosis
This study was conducted in 9 district-level microscopy centres in Assam and Tripura, India
Abstract
Setting
9 district-level microscopy centres in Assam and Tripura, India.
Objective
Same-day sputum microscopy is now recommended for tuberculosis (TB) diagnosis. We compared this method against the conventional 2-day approach in routine programmatic settings.
Methods
During October–December 2012, all adult presumptive TB patients were requested to provide 3 sputum samples for examination by Ziehl-Neelsen smear microscopy. Detection of acid-fast bacilli with any sample was diagnostic. The first and second spot sample comprised the same-day approach, and the first spot sample and next-day sample comprised the 2-day approach.
Results
Of 2168 presumptive TB patients, 403 (18.6%) were smear-positive according to the same-day method compared to 427 (19.7%) by the 2-day method (McNemar’s test, P < 0.001). Of the total 429 TB patients, 26 (6.1%) were missed by the same-day method and 2 (0.5%) by the 2-day method.
Conclusion
Same-day specimen collection for microscopy missed more TB than 2-day collection. In India, missing cases by using same-day microscopy would translate into a considerable absolute number, hindering TB control efforts. We question the indiscriminate switch to same-day diagnosis in settings where patients reliably return for testing the next day.
This research was supported by the UK Department for International Development’s Operational Research Capacity Building Programme led by the International Union Against TB and Lung Disease (The Union)
Citation
D. J. Deka, B. Choudhury, P. Talukdar, T. Q. Lo, B. Das, S. A. Nair, P. K. Moonan, A. M. V. Kumar (2016). What a difference a day makes: same-day versus 2-day sputum smear microscopy for diagnosing tuberculosis. Public Health Action. 2016 Dec 21; 6(4): 232–236. doi: 10.5588/pha.16.0062