DIAGNOSTIC YIELD OF BRONCHOALVEOLAR LAVAGE GENE XPERT IN SPUTUM NON-PRODUCERS AND SMEAR NEGATIVE, PULMONARY TUBERCULOSIS CASES AT IRD, SMS MEDICAL COLLEGE, JAIPUR.

Abstract

Background: Tuberculosis (TB) has been and remains a major global health problem. India accounts for one fourth of the global TB burden.

Methods: This was a tertiary hospital based, descriptive type of observational study conducted on fifty consecutive patients with clinicoradiologically consistent pulmonary tuberculosis who were either sputum smear negative for AFB or sputum non-producers at the Department of Tuberculosis and Chest Diseases, Institute of Respiratory Diseases, Jaipur from October 2017 to October 2018.

Results: The positivity of BAL AFB smear & Gene Xpert were 15 (30%) & 32 (64%) respectively. With BAL MTB culture as the gold standard, BAL AFB smear showed a sensitivity of 35%, specificity of 90%, positive predictive value (PPV) of 93.3%, negative predictive value (NPV) of 25.7%. BAL Gene Xpert showed a sensitivity of 72.5%, specificity of 70% and PPV of 90.60% and NPV of 38.9%.

Conclusion- GeneXpert and AFB smear microscopy share almost same specificity but sensitivity of GeneXpert is much higher than AFB smear microscopy in respiratory samples as shown in our study.

Keywords: GeneXpert, AFB smear microscopy, Specificity, Sensitivity.