Title: Evaluation of Xpert MTB/RIF assay for the diagnosis of extra pulmonary tuberculosis
Author: Juhi Taneja, Biswajit Sen, Sheetal Rani and Navin Dang
Institute: Dr Dang’s Laboratory Pvt. Ltd. New Delhi
Email of corresponding author: firstname.lastname@example.org
Introduction:The Xpert MTB/RIF assay (Cepheid, USA) is a catridge based real time polymerase chain reaction based molecular test with high accuracy for pulmonary TB detection (sensitivity 89%, specificity 99%).After the policy update by WHO in 2013, the Xpert MTB/RIF assay has been endorsed for detection of extrapulmonary tuberculosis as well; thereby providing rapid and accurate testing for extrapulmonary tuberculosis which accounts for approximately 25% of all tuberculosis cases.
Objective: To determine the prevalence of Rifampicin resistance in extrapulmonary samples by Xpert MTB/RIF assay.
Material and Methods: A total 321 extra pulmonary specimens (90 urine, 77 Pus, 8 tissue, 17 pleural fluid, 10 cerebrospinal fluid (CSF), 8 ascitic fluid, 8 synovial fluid, 15 semen, and 88 endometrial biopsy specimens) were submitted to the Laboratory for mycobacterial testing with the GeneXpert® MTB/RIF system, and microscopy from May 2013 to May 2014.
Result: Out of 321 samples tested,67 (20.9%) were positive for Mycobacterium tuberculosis and 7 (10.4%) were positive for Rifampicin resistance.30 (9.3%) cases were detected by ZN smear microscopy.
Conclusion: Xpert MTB/RIF assay is a reliable technique for the rapid and simultaneous detection of Mycobacterium tuberculosis and Rifampicin resistance from extrapulmonary samples.Leave a reply →