Same-day sputum smear microscopy for the diagnosis of pulmonary tuberculosis: direct vs. concentrated smear.

OBJECTIVE: To evaluate the efficacy of sputum microscopy by the concentration method using spot and morning and same-day smears for the diagnosis of pulmonary tuberculosis. METHODS: Three sputum specimens (spot, second spot and morning) were collected from study participants. Three smears were prepared from the direct sample and three using the N-acetyl-l-cysteine-sodium hydroxide concentration method. The smears were stained using Ziehl-Neelsen (ZN) staining, modified ZN (MZN) staining and fluorescent staining (FS). Smear results were pooled and compared in two categories: standard spot and morning, and same-day smears. The χ(2) test was used to evaluate the statistical difference in smear-positive cases. RESULTS: Among 3186 participants included in the study, smear positivity was respectively 9.6%, 9.8% and 10.8% for ZN, MZN and FS smears using spot and morning smears. Using same-day smears, smear positivity was respectively 9.5%, 9.8% and 10.6% for ZN, MZN and FS smears. Smear positivity increased to 16% with the concentration method. CONCLUSION: Nil dropouts and patient convenience are the added advantages of using same-day smears, and the concentration method improved smear positivity. Given these advantages, using same-day smears with the concentration method should be considered by the World Health Organization and India's Revised National Tuberculosis Control Programme.

Same day sputum smear microscopy approach with modified ZN staining for the diagnosis of pulmonary tuberculosis in a microscopy centre at Rajahmundry.

BACKGROUND: Sputum smear microscopy is the main-stay in the diagnosis of pulmonary tuberculosis in many developing countries. To overcome the drop outs, same day diagnosis is ideal. MATERIALS AND METHODS: In the current study, two spot sputum samples (SS 2 approach) are collected within a gap of one hour (same day sputum smear microscopy) in addition to the standard spot morning (SM) approach. The smears were stained with standard Ziehl Neelsen (ZN) and modified ZN staining techniques. RESULTS: Out of 1537 patients, sputum smear positivity (SSP) was 9.43% (146 patients) in SM approach with standard ZN staining. Smear positivity was increased to 9.8% (151 patients) with modified ZN staining. For SS 2 approach, SSP was 9.37% (144 patients) and 9.8% (151 patients) with standard and modified ZN staining procedures, respectively. CONCLUSIONS: Diagnosis of lung tuberculosis is possible with two spot sputum samples with modified ZN staining.