Performance characteristics of five antigen-detecting rapid diagnostic test (Ag-RDT) for SARS-CoV-2 asymptomatic infection: a head-to-head benchmark comparison

Abstract

Background: Mass testing for early identification and isolation of infectious COVID-19 individuals, irrespective of concurrent symptoms, is an efficacious strategy to reduce disease transmission. Antigen-detecting rapid diagnostic tests (Ag-RDT) appear as a potentially suitable tool for mass testing on account of their ease-of-use, fast turnaround time, and low cost. However, benchmark comparisons are scarce, particularly in the context of unexposed asymptomatic individuals. \nMethods: We used nasopharyngeal specimens from unexposed asymptomatic individuals to assess five Ag-RDTs: PanBioTM COVID-19 Ag Rapid test (Abbott), CLINITEST Rapid COVID-19 Antigen Test (Siemens), SARS-CoV-2 Rapid Antigen Test (Roche Diagnostics), SARS-CoV-2 Antigen Rapid Test Kit (Lepu Medical), and COVID-19 Coronavirus Rapid Antigen Test Cassette (Surescreen). Samples were collected between December 2020-January 2021 during the third wave of the epidemic in Spain.\nFindings: The analysis included 101 specimens with confirmed positive PCR results and 185 with negative PCR. For the overall sample, the performance parameters of Ag-RDTs were as follows: Abbott assay, sensitivity 38,6% (95% CI 29,1 to 48,8) and specificity 99,5% (9 to 100%); Siemens, sensitivity 51,5% (41,3 to 61,6) and specificity 98,4% (95,3 to 99,6); Roche, sensitivity 43,6% (33,7 to 53,8) and specificity 96,2% (92,4 to 98,5); Lepu, sensitivity 45,5% (35,6 to 55,8) and specificity 89,2% (83,8 to 93,3%); Surescreen, sensitivity 28,8% (20,2 to 38,6) and specificity 97,8% (94,5 to 99,4%). For specimens with cycle threshold (Ct) 99% and a PPV<50% at 1% prevalence. \nInterpretation: Two commercial, widely available assays can be used for SARS-CoV-2 antigen testing to achieve sensitivity in specimens with a Ct