ABSTRACT
BACKGROUND: Detection of SARS-CoV-2 infections relies on the use of sensitive, accurate and high throughput RT-PCR assays. OBJECTIVES: We assessed the analytical performance of the Abbott RealTime SARS-CoV-2 (RT-SARS), Alinity m SARS-CoV-2 (AlinSARS) assays and compared the clinical performance of the RT-SARS, AlinSARS, and Alinity m Resp-4-Plex (Alin4Plex) assays to the Seegene Allplex assay (Allplex) and an inhouse test (Inhouse). RESULTS: We found 100 % positive percent agreement (PPA) and 100 % negative percent agreement (NPA) comparing RT-SARS and Allplex. RT-SARS, AlinSARS and Inhouse showed 100 % NPA and 100 % PPA across all assays, except for the RdRp target of Inhouse (PPA = 84 %). Similarly, Alin4Plex and Allplex showed high agreement with specimens containing either SARS-CoV-2, influenza A, influenza B, or RSV. Detection rates of 100 % for SARS-CoV-2 at 50 copies/mL, high precision, and no cross-reactivity with non-SARS-CoV-2 respiratory pathogens were observed for RT-SARS and AlinSARS. AlinSARS detected SARS-CoV-2 in spiked throat washes and in specimens infected with SARS-CoV-2 Alpha or Beta variants. CONCLUSIONS: The newly developed RT-SARS, AlinSARS, and Alin4Plex assays proved to be useful for detecting SARS-CoV-2 RNA in clinical samples.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , RNA, Viral/genetics , Sensitivity and SpecificityABSTRACT
Mass molecular diagnostic testing for the SARS-CoV-2 pandemic has drawn on laboratory developed tests, commercial assays, and fully-automated platforms to accommodate widespread demand. The Alinity m instrument by Abbott is capable of detecting several clinically relevant pathogens and has recently received FDA emergency use authorization for SARS-CoV-2 molecular testing. The Alinity m performs automatic sample preparation, RT-PCR assembly, amplification, detection, and result calculation in under two hours. Here, we validate the performance characteristics of the Alinity m SARS-CoV-2 assay in comparison with the Roche cobas 6800 and Hologic Panther Fusion platforms. Across 178 positive and 195 negative nasopharyngeal swab specimens (CT range 14.30-38.84), the Alinity m detected one additional positive specimen that was found to be negative on the Roche cobas 6800 (PPA 100%, NPA 99.5%). Across a separate set of 30 positive and 174 negative nasopharyngeal swab specimens (CT range 14.1-38.5), the Alinity m had 100% positive and negative agreement with the Hologic Panther Fusion. Using SeraCare SARS-CoV-2 RNA standards, the assay limit of detection was verified to be two-fold more sensitive than the parameters stated by the SARS-CoV-2 AMP kit package insert, at 50 virus copies/mL. Assay specificity was 100% over 20 specimens positive for other respiratory viruses and intraday precision was 100% concordant with <2% CV. These data illst u illustrate the Abbott Alinity m system's high concordance with reference assays and analyti high analytical for SARS-CoV-2 molecular detection.