Patterns of Extrapulmonary Tuberculosis and the Role of Cartridge-Based Nucleic Acid Amplification Test in the Diagnosis of Extrapulmonary Tuberculosis

A BSTRACT Background: Extrapulmonary tuberculosis (EPTB) was underdiagnosed due to its varying and nonspecific symptoms and limited diagnostic tools. Recent data suggest that there is an increase in the incidence of EPTB due to the availability of the newer diagnostic tools. Objectives: This study aims to evaluate the patterns and role of newer diagnostic tools, such as cartridge-based nucleic acid amplification test (CBNAAT), in EPTB. Methods: Six hundred and thirty-six patients with a presumptive diagnosis of EPTB were subjected to diagnostic tools, such as cartridge-CBNAATs, Ziehl–Neelsen (Z–N) stain, and cytology or histopathology. Results: Out of 636 presumptive cases of EPTB, 116 cases were positive for tuberculosis. The cartridge-CBNAAT showed positivity in all 116 cases. Out of these 116 EPTB cases, only 10 cases were positive on Z–N stain, and 24 cases were positive on cytology and histopathology. The most common sites affected were the lymph nodes and the pleural cavities. Conclusion: Cartridge-CBNAAT gives a rapid result and plays a significant role in the diagnosis of EPTB.