Same day sputum smear microscopy for the diagnosis of Pulmonary Tuberculosis

Abstract

ZN staining is a common sputum microscopy technique used for the newlinediagnosis of TB. As per the literature (Selvakumar et al. 2002; Selvakumar et al. newline2005), in ZN staining, the concentration of phenol should be 5% and basic newlineFuchsin (BF) should be 1%; otherwise, the smear positivity can be reduced newlineautomatically. The RNTCP (1998), Government of India, recommends usage of newline1% BF in ZN staining, 5-min exposure time, while WHO (Weyer, 1998) and the newlineInternational Union Against Tuberculosis and Lung Disease (IUATLD) (2000) newlineguidelines recommend only 0.3% BF. Deun et al. (2005) showed that ZN newlinestaining with 1% BF for 15 min might be superior to 0.3% BF for 5 min. Hence, newlinein this study, prolonged primary staining step (15 min) is used for the sputum newlinesmears to identify tubercle bacilli. In India, serial sputum microscopy by light newlineemitting diode (LED) fluorescence microscopy (FM) is the technique being newlineused. Hence, in this study, fluorescent staining (FS) technique is also evaluated newlineto stain the sputum smears. Several modifications of ZN staining were reported newlinein the literature. But, in the available literature, modifications of ZN staining on newlineeconomical decolorisation are limited. Hence acid fast staining by jar method newlineand reverse ZN (RZN) staining techniques was also evaluated. The newlinediagnostic utility of same day approach is at par with the standard spot morning newlineapproach in the detection of the pulmonary tuberculosis. With same day newlineapproach, repeated hospital visits are not required for the diagnosis or for report newlinecollection or for treatment. In addition to patient convenience, smear negative newlinepatients can undergo GeneXpert evaluation on the same day and same day newlineinitiation of treatment is the added advantage of same day approach