Utility of Xpert® MTB/RIF assay for extrapulmonary tuberculosis, a two year study

<b>Introduction:</b> Tuberculosis is major health concern worldwide. Extra pulmonary Tuberculosis accounts for 20% cases which remain undetected due to its diverse clinical presentation and lack of diagnostic means. Early detection of tuberculosis and multidrug resistance is a priority in diagnosis of tuberculosis. <b>Aim:</b> To evaluate the utility of Xpert® MTB/RIF assay in the extra pulmonary tuberculosis samples. <b>Material and Methods:</b> Different body fluid specimens with strong clinical suspicion and microscopic examination negative for Acid-fast bacilli were send for Xpert® MTB/RIF assay under Revised National Tuberculosis Control Programme, over 2 years. <b>Results:</b> Xpert® MTB/RIF assay was performed on 227 body fluid samples. 34 were positive for Mycobacterium Tuberculosis with positivity rate of 64.7%(11/28) for pus(pyothorax, psoas abscess, synovial abscess), 21.2%(28/160) for pleural fluid, 15.3%(2/15) for gastric aspirate, 12.5%(1/9) for CSF and 7.1%(1/15) for ascitic fluid. Rifampicin resistance was detected in 9.7%(3/34), 2 of the pus and 1 of the gastric aspirate samples. <b>Conclusion:</b> Xpert® MTB/RIF assay is an efficient, reliable and fast technique with good potential in rapid diagnosis of extrapulmonary tuberculosis in pyogenic body fluids. But in others (pleural fluid, ascitic fluid, CSF, gastric aspirate) it is not sensitive, efficient and cost-effective to be recommended for diagnosis of extrapulmonary tuberculosis. However, it significantly reduces the time compared to culture methods in making diagnosis and initiation of treatment. Therefore it can be used routinely in diagnosing extrapulmonary tuberculosis but there is still a scope of further research for more reliable, sensitive and specific investigation of choice.