Xpert MTB/RIF Ultra and Xpert MTB/RIF for diagnosis of tuberculosis in an HIV-endemic setting with a high burden of previous tuberculosis: a two-cohort diagnostic accuracy study

Publication date: Available online 14 February 2020Source: The Lancet Respiratory MedicineAuthor(s): Hridesh Mishra, Byron W P Reeve, Zaida Palmer, Judy Caldwell, Tania Dolby, Charissa C Naidoo, Jennifer G Jackson, Samuel G Schumacher, Claudia M Denkinger, Andreas H Diacon, Paul D van Helden, Florian M Marx, Robin M Warren, Grant TheronSummaryBackgroundXpert MTB/RIF Ultra (Ultra) is a new test for tuberculosis undergoing global roll-out. We assessed the performance of Ultra compared with Xpert MTB/RIF (Xpert) in an HIV-endemic setting where previous tuberculosis is frequent and current test performance is suboptimal.MethodsIn this two-cohort diagnostic accuracy study, we used sputum samples from patients in South Africa to evaluate the accuracy of Ultra and Xpert against a single culture reference standard. For the first cohort (cohort A), we recruited adults (aged ≥18 years) with symptoms of presumptive tuberculosis at Scottsdene clinic in Cape Town, South Africa. We collected three sputum samples from each patient in cohort A, two at the first visit of which one was tested using Xpert and the other was tested using culture, and one sample the next morning which was tested using Ultra. In a separate cohort of patients with presumptive tuberculosis and recent previous tuberculosis (≤2 years) who had submitted sputum samples to the National Health Laboratory Services (cohort B), decontaminated sediments were, after processing, randomly allocated (1:1) for testing with Ultr...
Source: The Lancet Respiratory Medicine - Category: Respiratory Medicine Source Type: research