Diagnostic role of Xpert-MTB RIF assay in osteoarticular tuberculosis: A retrospective study

Core Tip

Core Tip: Osteoarticular tuberculosis (OATB) is a severe form of extrapulmonary tuberculosis (TB) that needs prompt management. However, there is difficulty in collecting samples and, secondarily, the paucibacillary nature of the lesion gives poor sensitivity and reproducibility, often with long turnaround time of the routine conventional laboratory tests. Xpert MTB RIF assay has been approved by the World Health Organization for rapid diagnosis of pulmonary/extrapulmonary TB. This study aims to find the diagnostic efficiency of gene Xpert for OATB in suspected patients. We found sensitivity of gene Xpert assay, culture, and smear when compared with CRS to be 94.6%, 13.5%, and 16.2%, respectively, while specificity in all the three types of tests was 100%. The kappa percentage of agreement for gene Xpert, culture, and microscopy were found to be 95%, 20%, and 22.6%, respectively. Follow-up of the gene Xpert positive patients after getting anti-tubercular treatment revealed improvement of their conditions. We conclude that gene Xpert has higher sensitivity than other conventional tests for the timely diagnosis of OATB.