Enhancing Sensitivity of Ziehl-Neelsen Stain Using Sodium Hypochlorite Sedimentation Technique for Diagnosis of Undiagnosed Cases of Smear Negative Pulmonary Tuberculosis

Tuberculosis is the chronic infectious disease and for its diagnosis battery of investigations are done. Ziehl Neelsen staining for detection of causative Acid Fast Bacilli is one of them. Positive smears diagnose the disease but negative smears doesn’t exclude the disease. We here done attempt to diagnose the undiagnosed cases by modifying the conventional ZN staining method. Patients suspicious of having pulmonary Tuberculosis were included in the study. Sputum examination was done by Ziehl-Neelsen staining method. Acid Fast Bacilli positive sputum samples were excluded from the study. Total 120 confirmed smear negative cases by conventional Ziehl-Neelsen method were studied. Sputum samples were processed for Culture and sodium hypochlorite sedimentation technique. Smears were stained by ZN method after sodium hypochlorite sedimentation technique. Of 120 initial negative cases 8 cases were found to be positive. Culture was positive in 10 cases. Thus this study was an attempt to show the increase in sensitivity of conventional ZN staining with the use of sodium hypochlorite concentration.