CHANGING DYNAMICS IN EXTRAPULONARY TUBERCULOSIS DETECTION AND ROLE OF CARTRIDGE-BASED NUCLEIC ACID AMPLIFICATION TEST IN ITS DIAGNOSIS

Introduction: Extrapulmonary Tuberculosis (EPTB) accounts for 15%–53% of all TB cases. Diagnosis is challenging due to its paucibacillary nature. In recent years, the Cartridge-based Nucleic Acid Amplification (CBNAAT) has emerged as a diagnostic tool with higher sensitivity. Literature on CBNAAT for an extra pulmonary sample is limited. Hence the study was conducted to evaluate the role of CBNAAT in early diagnosis of EPTB, and also to seek the spectrum of extrapulmonary tubercular infection and determine Rifampicin resistance among them from this region. Material And Methods: In this cross-sectional, laboratory-based comparative study of 1 year duration, 246 samples from suspected EPTB cases were subjected to ZN stain microscopy and CBNAAT, and diagnostic methods were compared (ZN smear, CBNAAT and liquid Culture). Thorough clinical corelation were made. For all CBNAAT positive samples rifampicin resistance were noted as marker for MDR TB. Results: The positivity rate of CBNAAT (19.9%) was higher than that of ZN smear (4%) and Liquid culture (18%). Most common EPTB in our study was found in tubercular lymphadenopathy followed by tubercular meningitis. Rifampicin resistance was found to be 8.16% among EPTB cases. Results was entered into Microsoft excel format and diagnostic test were evaluated by SPSS version-22 using liquid culture as reference. Conclusion:CBNAATwas found to be more sensitive than liquid culture for suspected EPTB cases. It also has added advantage of early detection, significantly reduced turnaround time, and ability to indicate MDR-TB (RIF resistance) for early initiation of appropriate treatment.