Role of cartridge-based nucleic acid amplification test in diagnosing extrapulmonary tuberculosis

Abstract

Background: Tuberculosis (TB) is a major health concern globally. Extrapulmonary tuberculosis (EPTB) accounts for around 20% of the total (EPTB) cases which are difficult to diagnose due to the lack of availability of diagnostic tools. Although pulmonary TB is most common presentation, EPTB is also an important problem clinically. Cartridge-based nucleic acid amplification (CBNAAT) test has a well-documented role in diagnosing pulmonary tuberculosis. The potency of CBNAAT in the diagnosis of EPTB cases is still debated. Aim: To establish the importance and role of diagnosing EPTB by CBNAAT. Settings: Conducted in Dr. D Y Patil Medical College Hospital and Research Centre, Dr. D Y Patil Vidyapeeth, Pimpri, Pune-411018. Design: Retrospective cross-sectional study of suspected EPTB patients in a tertiary care center area from April 2020 to September 2020. Materials and Methods: Data of suspected EPTB patients were retrieved. Potency of CBNAAT in diagnosing EPTB was assessed. Statistical Analysis: All the statistical analyses were carried out using the Statistical Package for the Social Sciences (SPSS) version 20. Results: Samples collected from 556 suspected EPTB patients were subjected to CBNAAT. The collected samples included pus, pleural fluid, cerebrospinal fluid, gastric aspirate, peritoneal fluid, tissue biopsy, pericardial fluid, ascitic fluid, synovial fluid, drain fluid, para-spinal fluid. In CBNAAT results, 67 cases were positive for TB bacilli, rifampicin resistance detected in 4 samples. Conclusion: Xpert®MTB/RIF assay is a rapid and effective method for early detection of EPTB and can be used in conjunction with routine culture methods for detection of the same.

Keywords

• cartridge-based nucleic acid amplification test
• extrapulmonary tuberculosis
• genexpert
• rifampacin