Comparative evaluation of Xpert MTB/RIF and the new Xpert MTB/RIF ultra with respiratory and extra-pulmonary specimens for tuberculosis case detection in a low incidence setting

摘要

The Xpert MTB/RIF assay (Xpert) is an automated molecular test for the detection of tuberculosis and rifampin resistance (RIF-R), but it lacks sensitivity in smear-negative samples and some limitations in determination of RIF-R have also been reported. The new Xpert MTB/RIF Ultra (Ultra) was developed to overcome these limitations. We aimed to compare Ultra and Xpert diagnostic accuracy setting culture and drug susceptibility testing as reference standards.