Role of automated GenexpertMTb/Rif system for rapid detection of Mycobacterium tuberculosis and Rifampicin resistance in extrapulmonary tuberculosis: A prospective study


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Article type :

Original Article

Author :

Mrugesh Desai, Meghna Patel, A T Leuva

Volume :

5

Issue :

1

Abstract :

Introduction: Extrapulmonary Tuberculosis is infection of mycobacterium tuberculosis involving organ other than lung. It account for 15-20% of all TB cases. Various combined approach used for diagnosis of Extrapulmonary TB. GeneXpert MTB/RIF System is cartridge based nucleic acid amplification test to detect tuberculosis and rifampicin resistance in two hours. Materials and Methods: This hospital based prospective study was carried out for period of 6 months with objective:-1) To evaluate the efficacy of GeneXpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis (EPTB) by comparing it with composite reference standard which include smear microscopy, clinical findings at time of presentation and three months follow up and radiological investigations.2) To look for Rifampicin Resistance by GeneXpert. Results: Out of total of 168 enrolled patients 135 patients met the criteria of composite reference standard (CRS). Among total 135 CRS ve EPTB Cases, 23 were paediatric (below 12 years of age) and 112 were Adults. Smear Microscopy was positive in 18 patients while GeneXpert gave positive results in 38 patients (8 paediatric and 30 adult patients). Rifampicin resistance was detected in 4 patients. Pleural effusion is the most commonly obtained sample followed by CSF, lymphnode, ascitic, urine, other fluid. Conclusions: Sensitivity of GeneXpert is more as compared to smear microscopy. GeneXpert showed better sensitivity in CSF, tissue, lymphnode, pleural and urine. So early microbiological diagnosis and Rifampicin drug sensitivity in Extrapulmonary sample lead to early treatment initiation of Tuberculosis and decrease morbidity and mortality due to tuberculosis. RNTCP has also recommended use of GeneXpert in suspected TB in Extrapulmonary sites.

Keyword :

 GeneXpert, Extrapulmonary Tuberculosis, Smear Microscopy, Sensitivity.