Xpert MTB/RIF®, a novel automated polymerase chain reaction-based tool for the diagnosis of tuberculosis [Technical note]

There is an urgent need for new point of care tests for tuberculosis (TB). Xpert MTB/RIF® is a real-time polymerase chain reaction-based system that detects Mycobacterium tuberculosis DNA and rifampicin (RMP) resistance modulating mutations directly from clinical samples in 2 h. The sensitivity for detecting M. tuberculosis in culture-positive samples was 93.8% (60/64) and exceeded smear microscopy (40/64, 62.5%). The specificity for detecting M. tuberculosis was 92.0% (23/25) and for RMP resistance it was 100% (8/8). The test is simple to conduct and requires basic sputum handling facilities only. These characteristics render it a promising close-to-patient test for TB in various settings.