Accuracy and incremental yield of urine Xpert MTB/RIF Ultra vs. Determine TB-LAM for diagnosis of pulmonary tuberculosis

• Published in: Diagnostic microbiology and infectious disease Vol. 96; no. 1; p. 114892
• Main Authors: Andama, A, Jaganath, D, Crowder, R, Asege, L, Nakaye, M, Katumba, D, Mwebe, S, Semitala, F, Worodria, W, Joloba, M, Mohanty, S, Somoskovi, A, Cattamanchi, A
• Format: Journal Article
• Language: English
• Published: 04-09-2019
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2019.114892

The performance of urine Xpert MTB/RIF Ultra (Xpert Ultra) for pulmonary TB diagnosis is unknown. HIV-positive and HIV-negative adults were enrolled at two health facilities in Kampala, Uganda. We compared the accuracy of urine Xpert Ultra and Determine TB-LAM in reference to sputum-based testing (positive Xpert MTB/RIF or culture), and assessed incremental yield. Urine Xpert Ultra had low sensitivity (17.2%, 95% CI 12.3–23.2) but high specificity (98.1%, 95% CI 94.4–99.6). Sensitivity reached 50.0% (95% CI 28.2–71.8) among HIV-positive patients with CD4 <100 cells/μL. Compared to Determine TB-LAM, urine Xpert Ultra was 9.4% (95% CI 3.8–14.9, p=0.01) more sensitive, and 17.2% (95% CI 4.5–29.8, p=0.01) more sensitive among HIV-positive patients. However, the incremental sensitivity of urine Xpert Ultra relative to sputum Xpert MTB/RIF was only 1% (95% CI −0.9 to 2.8). Urine Xpert Ultra could be an alternative for patients with advanced HIV infection unable to produce sputum.