Background: There are limited data about Xpert-Ultra performance in different settings, in HIV-infected persons, in those with a history of previous TB, and with trace readouts.
Methods: We evaluated the relative accuracy of Xpert-MTB/RIF and Xpert-Ultra in 272 selected but well-characterized archived sputum samples. Of these, 168 were culture-positive (64/168 smear-positive and 104/168 smear-negative), and 104 were culture-negative (102/104 from patients with previous TB and 2/104 from patients without a TB history). Assay-specific limit-of-detection (LOD) experiments were conducted using serial dilutions of Mycobacterium tuberculosis H37Rv.
Results: Overall sensitivity (95%CI) in smear-negative culture-positive samples for Xpert-MTB/RIF and Xpert-Ultra were 71.2% (62.5-79.9) and 77% (68.9-85.1), respectively (and in HIV-infected persons: 63.5% (50-76.1) and 73.1% (61.1-85.2), respectively). The LOD for Xpert-Ultra was lower (9 versus 184 CFU/ml). There were a total of 9/272 (3.3%) Xpert Ultra trace readouts (6/104 [5.8%]) in smear-negative culture-positive persons, and 3/102 (3%) in culture-negative non-TB persons with a history of previous TB).
Conclusions: Xpert-Ultra had a lower LOD compared to Xpert-MTB/RIF. A small proportion of samples (<5%) from culture-negative patients but with a history of previous TB had a likely false-positive trace readout. These data inform the management of patients with suspected TB in endemic settings.
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http://dx.doi.org/10.1016/j.ijid.2020.03.025 | DOI Listing |
Ther Adv Infect Dis
December 2024
Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud, Universidad San Ignacio de Loyola, Lima, Campus 2, avenida La Fontana 750, La Molina, Lima, Peru.
Background: Molecular tests have contributed to reducing the mortality rate through early and accurate diagnosis of tuberculosis (TB). This is due to their low processing complexity and diagnostic accuracy superior to conventional methods.
Objective: To evaluate the diagnostic performance of Cobas MTB and Logix Smart MTB compared to Xpert MTB/RIF Ultra for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB).
Clin Infect Dis
December 2024
FIND, Geneva, Switzerland.
Background: Drug susceptibility testing (DST) is essential for starting people on effective tuberculosis (TB) regimens. No published data exists for the high-throughput LiquidArray MTB-XDR (LA-XDR) test, which detects Mycobacterium tuberculosis complex (MTBC) and fluoroquinolone, amikacin, ethambutol, and linezolid susceptibility (latter two have no rapid DSTs available).
Methods: We enrolled people (n=720) with presumptive TB who provided two sputa for a Xpert MTB/RIF Ultra and a culture (MTBC reference standard).
Objectives: To evaluate the performance of Xpert MTB/RIF Ultra testing in urine samples as part of a TB screening strategy in patients with advanced HIV disease (AHD).
Methods: We conducted a multicentre prospective cohort study across three HIV reference hospitals in Brazil, between January and December 2023. The study included adult hospitalized patients with AHD, defined by a CD4 count of <200 cells/μL in the last 3 months or clinical presentation suggestive of opportunistic infection, without effective antiretroviral treatment.
Am J Respir Crit Care Med
December 2024
University of California, San Francisco, Division of Pulmonary and Critical Care Medicine, San Francisco, United States.
: C-reactive protein (CRP)-based tuberculosis (TB) screening is recommended for people with HIV (PWH). However, its performance among people without HIV and in diverse settings is unknown. : In a multi-country study, we aimed to determine whether CRP meets the minimum accuracy targets (sensitivity ≥90%, specificity ≥70%) for an effective TB screening test.
View Article and Find Full Text PDFJ Mol Diagn
November 2024
Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, the Netherlands. Electronic address:
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