Comparative Evaluation of Rapid Isothermal Amplification and Antigen Assays for Screening Testing of SARS-CoV-2

Abstract

Human transmission of SARS-CoV-2 and emergent variants of concern continue to occur globally, despite mass vaccination campaigns. Public health strategies to reduce virus spread should therefore rely, in part, on frequent screening with rapid, inexpensive, and sensitive tests. We evaluated two digitally integrated rapid tests and assessed their performance using stored nasal swab specimens collected from individuals with or without COVID-19. An isothermal amplification assay combined with a lateral flow test had a limit of detection of 10 RNA copies per reaction, and a positive percent agreement (PPA)/negative percent agreement (NPA) during the asymptomatic and symptomatic phases of 100%/100% and 95.83/100%, respectively. Comparatively, an antigen-based lateral flow test had a limit of detection of 30,000 copies and a PPA/NPA during the asymptomatic and symptomatic phases of 82.86%/98.68% and 91.67/100%, respectively. Both the isothermal amplification and antigen-based lateral flow tests had optimized detection of SARS-CoV-2 during the peak period of transmission; however, the antigen-based test had reduced sensitivity in clinical samples with qPCR Ct values greater than 29.8. Low-cost, high-throughput screening enabled by isothermal amplification or antigen-based techniques have value for outbreak control.

Development of RT-RPA-based point-of-care tests for epidemic arthritogenic alphaviruses

“…At the outset, both approaches involve replacing one of the reaction primers with a 5’labelled version to generate a singly labelled amplification product. The first method involves a separate hybridization step, where the singly-labelled amplification product, is denatured and then hybridized with a labelled probe 32,40 . The second approach involves introducing an nfo-probe, which are labelled probes with an internal abasic site, into the reaction, along with an endonuclease (nfo or Endo IV) that cleaves at that abasic site upon probe hybridization 29 .…”

Nasal swab is a good alternative sample for detecting SARS-CoV-2 with rapid antigen test: A meta-analysis

“…Among the 49 studies on nasal swabs containing 79,073 samples [ [2] , [3] , [4] , 6 , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] ], all of them were published between 2021 and 2022, and twenty-one studies were conducted in the USA [ 12 , 14 , 15 , 18 , 21 , 22 , [25] , [26] , [27] , [32] , [33] , [34] , [35] , 39 , 44 , 45 , [47] ...…”

Update of European Society of Clinical Microbiology and Infectious Diseases coronavirus disease 2019 guidelines: diagnostic testing for severe acute respiratory syndrome coronavirus 2

“… In patients with signs and symptoms compatible with COVID-19, we suggest the use of rapid antigen detection testing in respiratory samples other than nasopharyngeal and saliva samples versus laboratory-based NAAT in samples other than nasopharyngeal and saliva samples for the diagnosis of COVID-19. Weak for Low [ 9 , 26 , [114] , [115] , [116] , [117] , [118] , [119] , [120] , [121] , [122] , [123] , 93 , [124] , [125] , [126] , [127] , [128] , [107] , [108] , [109] , [110] , [111] , [112] , [113] ] 15 In patients with signs and symptoms compatible with COVID-19 of equal or less than 7 days-onset , should rapid antigen detection testing be used, compared with standard NAAT (commercial and/or in house) for diagnosis of COVID-19? In patients with signs and symptoms compatible with COVID-19 of equal or less than 7 days-onset, we suggest the use of rapid antigen detection testing versus laboratory-based NAAT for the diagnosis of COVID-19.…”

“… In asymptomatic people, we suggest the use of laboratory-based NAAT in non-nasopharyngeal/non-saliva respiratory samples versus rapid antigen testing in non-nasopharyngeal/non-saliva for the diagnosis of COVID-19. Weak against Low [ 107 , 110 , 128 , 154 , 156 , 159 , 164 , 167 , 171 , 111 , 112 , 118 , [120] , [121] , [122] , 124 , 126 ] 6 In asymptomatic people should rapid antigen tests be used in saliva samples as compared laboratory based NAAT to diagnose COVID-19? In asymptomatic people, we suggest the use of laboratory-based NAAT in saliva samples versus rapid antigen testing in saliva for the diagnosis of COVID-19.…”