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DORWARD J, NAIDOO J, MOODLEY P, SOOKRAJH Y, SAMSUNDER N, SAYED F, NAICKER N, FANSHAWE T, DRAIN PK, LESSELLS RJ, HAYWARD G, BUTLER CC, GARRETT N. Diagnostic Accuracy of the Rapid Xpert HIV-1 Viral Load XC, Xpert HIV-1 Viral Load, & m-PIMA HIV-1/2 Viral Load in South African Clinics. J Acquir Immune Defic Syndr 2022; 91:189-196. [PMID: 36094486 PMCID: PMC7613592 DOI: 10.1097/qai.0000000000003037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/31/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND We aimed to evaluate the analytic performance of 3 rapid HIV viral load assays: the novel Xpert HIV-1 VL XC (Xpert XC), Xpert HIV-1 VL (Xpert VL), and m-PIMA HIV-1/2 VL (m-PIMA). SETTING Two South African clinics. METHODS We conducted a prospective diagnostic accuracy study. Site-laboratory technicians and nurses used the Xpert XC, Xpert VL, and m-PIMA to test plasma samples from people with HIV receiving antiretroviral therapy. We compared results with the Roche cobas HIV-1 reference assay. We determined accuracy to detect viraemia at the World Health Organization (WHO) failure threshold of 1000 copies/mL on all 3 assays, and 50 and 200 copies/mL on the Xpert assays. We assessed the agreement using Bland-Altman plots. RESULTS We enrolled 140 participants (98 [70%] women, median age 37 years), who provided 189 paired samples at one or more timepoints. We tested 174 samples with the Xpert XC, 188 with the Xpert VL, and 128 with the m-PIMA. At 1000 copies/mL, sensitivity and specificity (95% confidence intervals) were 97% (82 to 100) and 98% (93 to 99) (Xpert XC), 100% (87 to 100) and 96% (91 to 98) (Xpert VL), and 92% (72 to 99) and 99% (93 to 100) (m-PIMA) respectively. At 50 copies/mL, sensitivity and specificity were 93% (81 to 98) and 96% (91 to 99) (Xpert XC), and 95% (84 to 99) and 95% (90 to 98) (Xpert VL) respectively. Mean bias was -0.10 (-0.54 to 0.34) log10 copies/mL (Xpert XC), 0.07 (-0.37 to 0.52) log10 copies/mL (Xpert VL), and -0.26 (-0.83 to 0.31) log10 copies/mL (m-PIMA). CONCLUSIONS In these South African clinics, the accuracy of all 3 assays was clinically acceptable to detect viraemia at the WHO failure threshold, whereas both Xpert assays were also accurate at detecting low-level viraemia.
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Affiliation(s)
- Jienchi DORWARD
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
| | - Jessica NAIDOO
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
| | - Pravikrishnen MOODLEY
- Department of Virology, University of KwaZulu-Natal and National Health Laboratory Service, Inkosi Albert Luthuli Central Hospital, KwaZulu-Natal, South Africa
| | - Yukteshwar SOOKRAJH
- eThekwini Municipality Health Unit, eThekwini Municipality, Durban KwaZulu-Natal, South Africa
| | - Natasha SAMSUNDER
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
| | - Fathima SAYED
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
| | - Nivashnee NAICKER
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
| | - Thomas FANSHAWE
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Paul K DRAIN
- Department of Global Health, Schools of Medicine and Public Health, University of Washington, Seattle, USA
- Department of Medicine, School of Medicine, University of Washington, Seattle, USA
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, USA
| | - Richard J LESSELLS
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
- KwaZulu-Natal Research and Innovation Sequencing Platform (KRISP), University of KwaZulu-Natal, Durban, South Africa
| | - Gail HAYWARD
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Christopher C BUTLER
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, Oxfordshire, United Kingdom
| | - Nigel GARRETT
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu–Natal, Durban, KwaZulu-Natal, South Africa
- Discipline of Public Health Medicine, School of Nursing and Public Health, University of KwaZulu-Natal, Durban, KwaZulu-Natal, South Africa
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Majam M, Msolomba V, Venter F, Scott LE, Kahamba T, Stevens WS, Rademeyer M, van Tonder T, Karim S, Kadam R, Akugizibwe P. Monitored Implementation of COVID-19 Rapid Antigen Screening at Taxi Ranks in Johannesburg, South Africa. Diagnostics (Basel) 2022; 12:402. [PMID: 35204493 PMCID: PMC8871379 DOI: 10.3390/diagnostics12020402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/23/2022] [Accepted: 01/28/2022] [Indexed: 11/30/2022] Open
Abstract
Digital tools can support community-based decentralized testing initiatives to broaden access to COVID-19 diagnosis, especially in high-transmission settings. This operational study investigated the use of antigen-detecting rapid diagnostic tests (Ag-RDTs) for COVID-19 combined with an end-to-end digital health solution, in three taxi ranks in Johannesburg, South Africa. Members of the public were eligible if they were aged ≥18 years, could read, and had a cellphone. Over 15,000 participants, enrolled between June and September 2021, were screened for COVID-19 risk factors. A digital risk questionnaire identified 2061 (13%) participants as moderate risk and 2987 (19%) as high risk, based on symptoms and/or recent exposure to a known case. Of this group referred for testing, 3997 (79%) received Ag-RDTs, with positivity rates of 5.1% in the "high-risk" group and 0.8% in the "moderate-risk" group. A subset of 569 randomly selected participants received additional PCR testing. Sensitivity of the Ag-RDT in this setting was 40% (95% CI: 30.3%, 50.3%); most false negatives had high cycle threshold values (>25), hence low viral loads. Over 80% of participants who tested positive completed a 2-week phone-based follow-up questionnaire. Overall, the digital tool combined with Ag-RDTs enhanced community-based decentralized COVID-19 testing service delivery, reporting and follow-up.
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Affiliation(s)
- Mohammed Majam
- Ezintsha, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (V.M.); (F.V.)
| | - Vanessa Msolomba
- Ezintsha, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (V.M.); (F.V.)
| | - François Venter
- Ezintsha, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa; (V.M.); (F.V.)
| | - Lesley Erica Scott
- Department of Molecular Medicine and Haematology, University of the Witwatersrand, Johannesburg 2193, South Africa; (L.E.S.); (T.K.); (W.S.S.)
| | - Trish Kahamba
- Department of Molecular Medicine and Haematology, University of the Witwatersrand, Johannesburg 2193, South Africa; (L.E.S.); (T.K.); (W.S.S.)
| | - Wendy Susan Stevens
- Department of Molecular Medicine and Haematology, University of the Witwatersrand, Johannesburg 2193, South Africa; (L.E.S.); (T.K.); (W.S.S.)
- The National Priority Program of the National Health Laboratory Service, Johannesburg 2193, South Africa
| | - Michael Rademeyer
- A2D24, Albury Office Park, 5 Albury Rd., Dunkeld West, Randburg 2196, South Africa;
| | - Tanya van Tonder
- Opinion Solutions, Melrose Arch, 44 Melrose Blvd, Birnam, Johannesburg 2196, South Africa;
| | - Sanjida Karim
- FIND, Campus Biotech, Chemin des Mines 9, 1202 Geneva, Switzerland; (S.K.); (R.K.); (P.A.)
| | - Rigveda Kadam
- FIND, Campus Biotech, Chemin des Mines 9, 1202 Geneva, Switzerland; (S.K.); (R.K.); (P.A.)
| | - Paula Akugizibwe
- FIND, Campus Biotech, Chemin des Mines 9, 1202 Geneva, Switzerland; (S.K.); (R.K.); (P.A.)
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