Utilization of Xpert MTB/RIF assay in tertiary care hospital: Diagnostic accuracy of extrapulmonary tuberculosis specimens

Abstract

The performance of the Xpert MTB/RIF G4, the Xpert MTB/RIF Ultra and the AFB smear microscopy in detecting TB in extrapulmonary specimens from cerebrospinal fluid (CSF), body fluid, gastric content pus and lymphnode tissue and were submitted to laboratory for Mycobacteria diagnosis evaluated. Each sample from 95 of extrapulmonary specimens was divided for diagnosis using microscopy and Xpert MTB/RIF G4 assays, and each sample from 31 of extrapulmonary specimens was divided for diagnosis using microscopy and Xpert MTB/RIF Ultra assays; these were all comparatively evaluated, using the TB culture as a gold standard. For extrapulmonary specimen, the sensitivity and specificity were respectively: 66.67%, 98.80%, and 75.00, 96.30%. This result show that the new and improved Xpert MTB/RIF Ultra assay was more sensitive than GeneXpert G4 and AFB smear in extrapulmonary specimens.Tuberculosis