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

Abstract

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 (SS2 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 SS2 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.