Same-day sputum smear microscopy for the diagnosis of pulmonary tuberculosis - Light-emitting diode fluorescent staining with direct sputum versus Ziehl-Neelsen staining with concentration sputum

OBJECTIVE: The objective of the study was to evaluate the utility of fluorescent staining (FS) technique with direct sputum for the diagnosis of pulmonary tuberculosis (TB). METHODS: Three sputum specimens (spot, second spot, and morning) were collected from the study participants. One smear was prepared from the direct sample and one using the N-acetyl-L-cysteine-sodium hydroxide concentration method. The direct smears were stained using FS, and Ziehl-Neelsen (ZN) staining was used to stain smears prepared after concentration method. Smear results were pooled and compared in two categories: standard spot-morning and same-day smears. The Chi-square test was used to evaluate the statistical difference in smear-positive cases. RESULTS: Among 2922 participants included in the study, smear positivity was, respectively, 10.5% and 10.2% for FS and ZN smears using spot-morning approach. Using the same-day approach, the smear positivity was, respectively, 10.4% and 9.9% for FS and ZN smears; statistically, the difference was not statistically significant (P > 0.05) between the staining techniques in both the approaches. CONCLUSION: More smear positivity is the advantage of using FS technique. Given this advantage, National TB Control Programs of high-TB-burden countries should consider installing light-emitting diode FS technique in peripheral settings also.