EVALUATION OF NOVEL HYPERTONIC SALINE SODIUM HYDROXIDE (HS-SH) METHOD FOR DECONTAMINATION OF SPUTUM SAMPLES FOR DETECTION OF MYCOBACTERIUMTUBERCULOSIS IN A TERTIARY CARE HOSPITAL

INTRODUCTION Sputum microscopy remains the mainstay of diagnosis of pulmonary tuberculosis but lacks sensitivity compared to culture. Prerequisite for microscopic examination of sputum sample is prior decontamination. Conventional methods for decontamination include Petroffs method which is routinely done, while N-Acetyl-L-Cysteine Sodium Hydroxide (NALC-NaOH) still remains a gold standard.OBJECTIVES To evaluate the performance of the Novel Hypertonic Saline Sodium hydroxide (HS-SH) method with the standard NALC-NaOH for decontamination of sputum specimens.MATERIALS AND METHODS Total of 143 sputum samples obtained from both in-patients and out-patients of PSG Hospitals were subjected to decontamination by both HS-SH method and NALC-NAOH methods. Slides were then examined under oil immersion for acid fast bacilli by conventional Ziehl Neelsen staining method. RESULTS Out of 143 microbiological sputum samples, 104 were found to be positive for acid fast bacilli by both Modified petroffs method and Hypertonic saline sodium hydroxide method (HS-SH) of concentration and decontamination and 39 samples were negative by both these methods. Sensitivity, Specificity, Positive predictive value Negative predictive value of the HS-SH method was found to be 100.CONCLUSION The novel HS-SH decontamination method is equally sensitive, specific, cost-effective, feasible and less time consuming compared to the gold standard NALC-NaOH method for decontamination of Mycobacterium tuberculosis from sputum samples and can be routinely used in all peripheral health centres because of the low cost, especially in developing countries.