Role of cartridge-based nucleic acid amplification test to diagnose tuberculosis at tertiary care teaching hospital in Rajasthan, India

Rajendra Babu Mathur, Uma Shankar Shukla, Hemant Kumar Bindal


Background: Tuberculosis is one of the top 10 causes of death worldwide as per the Global TB report 2017, the estimated incidence of TB in India was approximately 28,00,000 cases accounting for about a quarter of the world’s TB cases (10 million). It is of utmost important to diagnose early and treat it to reduce disease transmission. GeneXpert MTB/RIF, an automated cartridge-based molecular technique detects Mycobacterium Tuberculosis and rifampicin resistance within two hours, has been recommended by WHO for rapid diagnosis of TB.

Methods: Author conducted a retrospective study in the Department of TB and Chest, of tertiary care center at Jhalawar Medical College (JMC), Jhalawar to evaluate and analyze the role of CBNAAT to diagnose tuberculosis from 1st January 2018 to 31st December 2018. Author included all patients who came to department of TB and Chest of JMC, Jhalawar either new/ relapsed/ defaulters/ referred cases from ART/ ICTC center, Pediatric Department; Gynaecology and Obstetrics Department, peripheral Government Health Care Facilities and Private Hospitals of Jhalawar District catering about 15.5 lac population were subjected to both ZN staining/ Fluorescent microscopy and CBNAAT in the study period.

Results: A total of 3078 samples (pulmonary 2739+EP 339) were tested for ZN staining / Fluorescent microscopy and CBNAAT during the study period. Mean age of the study population was 36.5±10.3 years. 1873 tested were negative and 1205 samples were positive for CBNAAT. Of these 1205 positive samples, 1174 were sputum/ BAL samples and 31 were extra pulmonary samples. Authors found rifampicin resistance rate of 6.98% (82/1174) in pulmonary tuberculosis cases, 3 rifampicin resistance cases were detected in extra pulmonary samples. CBNAAT could identify 255 cases (14.01%) that were smear negative. Author found TB-HIV coinfection rate of 18.75%.

Conclusions: Author found CBNAAT to be an important diagnostic modality especially in smear negative patients for early diagnosis and treatment. Author could detect Mycobacterium Tuberculosis in 14.01% of patients with negative smear microscopy for AFB. In PLHIV, CBNAAT detected Mycobacterium Tuberculosis in 18.75% (12/64) of patients. Author found rifampicin resistance rate of 6.98% (82/1174) in pulmonary tuberculosis cases.


Cartridge-based nucleic acid amplification test, Extra-pulmonary, People living with HIV, Smear negative, Tuberculosis

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