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Spooner E, Reddy S, Ntoyanto S, Sakadavan Y, Reddy T, Mahomed S, Mlisana K, Dlamini M, Daniels B, Luthuli N, Ngomane N, Kiepiela P, Coutsoudis A. TB testing in HIV-positive patients prior to antiretroviral treatment. Int J Tuberc Lung Dis 2022; 26:224-231. [PMID: 35197162 PMCID: PMC8886959 DOI: 10.5588/ijtld.21.0195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND: TB diagnosis in patients with HIV is challenging due to the lower sensitivities across tests. Molecular tests are preferred and the Xpert® MTB/RIF assay has limitations in lower-income settings. We evaluated the performance of loop-mediated isothermal amplification (LAMP) and the lipoarabinomannan (LAM) test in HIV-positive, ART-naïve clinic patients.METHODS: A total of 783 eligible patients were enrolled; three spot sputum samples of 646 patients were tested using TB-LAMP, Xpert, smear microscopy and culture, while 649 patients had TB-LAM testing. Sensitivity, specificity, and negative and positive predictive values were estimated with 95% confidence intervals.RESULTS: Sensitivities for smear microscopy, TB-LAMP and Xpert were respectively 50%, 63% and 74% compared to culture, with specificities of respectively 99.2%, 98.5% and 97.5%. An additional eight were positive on TB-LAM alone. Seventy TB patients (9%) were detected using standard-of-care testing, an additional 27 (3%) were detected using study testing. Treatment was initiated in 57/70 (81%) clinic patients, but only in 56% (57/97) of all those with positive TB tests; 4/8 multidrug-resistant samples were detected using Xpert.CONCLUSION: TB diagnostics continue to miss cases in this high-burden setting. TB-LAMP was more sensitive than smear microscopy, and if followed by culture and drug susceptibility testing as required, can diagnose TB in HIV-positive patients. TB-LAM is a useful add-in test and both tests at the point-of-care would maximise yield.
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Affiliation(s)
- E Spooner
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, Durban, South Africa, HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa
| | - S Reddy
- South African Medical Research Council, Durban, South Africa
| | - S Ntoyanto
- HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa
| | - Y Sakadavan
- HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa
| | - T Reddy
- Biostatistics Unit, South African Medical Research Council, Durban, South Africa
| | - S Mahomed
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa, Medical Microbiology Department, National Health Laboratory Services, Durban, South Africa, Centre for AIDS Programme Research in South Africa, Durban, South Africa
| | - K Mlisana
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa, Medical Microbiology Department, National Health Laboratory Services, Durban, South Africa
| | - M Dlamini
- Medical Microbiology Department, National Health Laboratory Services, Durban, South Africa
| | - B Daniels
- HIV Prevention Research Unit, South African Medical Research Council, Durban, South Africa
| | - N Luthuli
- EThekwini Health Unit, EThekwini Municipality, Durban, South Africa
| | - N Ngomane
- Occupational Health, Durban, South Africa
| | - P Kiepiela
- South African Medical Research Council, Durban, South Africa
| | - A Coutsoudis
- Department of Paediatrics and Child Health, University of KwaZulu-Natal, Durban, South Africa
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