Same day sputum smear microscopy for the diagnosis of pulmonary tuberculosis: Ziehl-Neelsen versus fluorescent staining

BACKGROUND: Sputum smear microscopy is the main tool for the diagnosis of pulmonary tuberculosis (TB), especially in low- and middle-income countries (LMICs). Limited sensitivity of smear microscopy and patient dropouts (PDs) are the important obstacles of national TB control programs. OBJECTIVES: (1) To assess the diagnostic utility of the same day (SS(2)) approach (2) To compare the smear results of the spot morning (SM) and the SS(2) approaches. MATERIALS AND METHODS: The study was conducted in the Department of Microbiology, GSL Medical College, Rajahmundry, Andhra Pradesh, India from January 2011 to February 2015. Three sputum samples were collected [spot (S), second spot (S(2)) 1 h after S, and morning sample (M)] from the volunteers. The sputum smears were stained by Ziehl-Neelsen (ZN), modified ZN (MZN), and fluorescent staining (FS) techniques and the results were pooled and compared under SM and SS(2) approaches. RESULTS: Of the 3,186 study participants, sputum smear positivity (SSP) for SM approach was 9.6% and 10.8% and for SS(2) approach, it was 9.4% and 10.6%, respectively, with ZN and FS and the results were statistically insignificant (Mann-Whitney U test, P > 0.05). CONCLUSION: Technically SSP was similar for both the approaches and no improvement was observed with the SS(2) approach. Hence, there is an urgent need to improve SSP.