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. 2022 Apr 15;89(5):537-545.
doi: 10.1097/QAI.0000000000002902.

Evaluation of SAMBA II: A Qualitative and Semiquantitative HIV Point-of-Care Nucleic Acid Test

Lauren R Violette  1   2 , Andy Cornelius-Hudson  1 , Madison Snidarich  1 , Lisa A Niemann  1 , Sonny Michael Assennato  3 , Allyson Ritchie  3 , Neha Goel  3 , Pollyanna R Chavez  4 , Steven F Ethridge  4 , David A Katz  5 , Helen Lee  3 , Kevin P Delaney  4 , Joanne D Stekler  1   2   5
Affiliations

Evaluation of SAMBA II: A Qualitative and Semiquantitative HIV Point-of-Care Nucleic Acid Test

Lauren R Violette et al. J Acquir Immune Defic Syndr. .

Abstract

Background: Point-of-care (POC) nucleic acid tests (NATs) have potential to diagnose acute HIV infection and monitor persons taking pre-exposure prophylaxis or antiretroviral therapy (ART). POC NATs have not yet been evaluated in the US.

Methods: From June 2018-March 2019, we conducted a cross-sectional evaluation of the Simple Amplification-Based Assay version II (SAMBA II) POC NAT. People with HIV (PWH) and persons testing for HIV were tested with the SAMBA II qualitative (Qual) whole blood (WB) test. From April-September 2019, the Qual test was used on persons who were ART-naive, and SAMBA II Semi-quantitative (Semi-Q) WB was used with ART-experienced PWH. Both were performed on unprocessed venipuncture (VP) and, when indicated by protocol, fingerstick (FS) WB and plasma. SAMBA results were compared with Abbott RealTime HIV-1 polymerase chain reaction results on plasma. We calculated sensitivity, specificity, and concordance between tests.

Results: SAMBA was used in 330 visits among 280 participants: 202 (61.2%) visits from PWH, and 128 (38.8%) from HIV-negative persons. Qual test sensitivity with ART-naive participants was 91.4% [32/35, 95% confidence interval (CI): 77.6% to 97.0%] using VP WB and 100% (27/27, 95% CI: 87.5% to 100%) using FS WB. Specificity was 100% using both specimen types. Concordance between the gold standard and Semi-Q at 1000 copies/mL among PWH on ART was 97.7% (86/88, 95% CI: 92.1% to 99.4%) and 100% (30/30, 95% CI: 88.7% to 100%) using VP and FS WB, respectively.

Conclusions: The SAMBA II POC NATs showed high sensitivity, specificity, and concordance with the gold standard assay, indicating its potential use in diagnostics and monitoring. Future work will evaluate POC NAT implementation in the US.

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Conflict of interest statement

S.M.A., A.R., N.G. and H.L. are employed by Diagnostics for the Real World (DRW), the creators of the SAMBA II test. DRW provided 2 SAMBA II machines for investigational use. The remaining authors have no conflicts of interest to disclose.

References

    1. Centers for Disease Control and Prevention. HIV Surveillance Report, 2018 (Updated); vol. 31. May 2020. Accessed December 14, 2020. http://www.cdc.gov/hiv/library/reports/hiv-surveillance.html.
    1. Division of HIV/AIDS Prevention. Basic Statistics. Centers for Disease Control and Prevention January 27, 2021. Accessed February 10, 2021. https://www.cdc.gov/hiv/basics/statistics.html.
    1. Joint United Nations Programme on HIV/AIDS (UNAIDS). 2025 AIDS Targets Accessed February 10, 2021. https://aidstargets2025.unaids.org/assets/images/prevailing-against-pand....
    1. Hutchinson AB, Branson BM, Kim A, Farnham PG. A meta-analysis of the effectiveness of alternative HIV counseling and testing methods to increase knowledge of HIV status. AIDS 2006;20(12):1597–1604. - PubMed
    1. Spielberg F, Branson BM, Goldbaum GM, et al. Choosing HIV counseling and testing strategies for outreach settings: a randomized trial. J Acquir Immune Defic Syndr 2005;38(3):348–355. - PubMed

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