Comparative evaluation of Panbio and SD Biosensor antigen rapid diagnostic tests for COVID-19 diagnosis

Abstract

The aim of our study was to evaluate the diagnostic performance of two antigen rapid diagnostic tests (Ag-RDTs) to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We evaluated Panbio and SD-Biosensor Ag-RDTs. We employed 186 polymerase chain reaction (PCR) negative samples to evaluate the specificity and 170 PCR positive samples to assess the sensitivity. We evaluated their sensitivity according to Cycle threshold (Ct) values and days post onset of symptoms (d.p.o.). Tests were compared using the McNemar's test. Agreement was evaluated using the kappa score. Specificity was 100% for Panbio and 97.3% for SD-Biosensor. Sensitivity for samples with Ct≤ 20 was 100% for both assays and for samples with Ct = 20–25 was 93.0% (Panbio) and 95.3% (SD-Biosensor) (p = 1.000). Sensitivity decreased for samples wit Ct = 25–30 (Panbio: 41.3%, SD-Biosensor: 52.2%, p = 0.125) and samples with Ct≥ 30 (Panbio: 5.0%, SD-Biosensor: 17.5%, p = 0.063). Sensitivity within seven d.p.o. was 87.7% for Panbio and 90.4% for SD-Biosensor and notably decreased after seven d.p.o. Agreement with PCR was excellent for high viral load samples (Ct ≤ 25): Panbio, 98.9%, kappa = 0.974; SD-Biosensor, 97.4%, kappa = 0.940. Agreement between Ag-RDTs was excellent (94.9%, kappa = 0.882). Panbio and SD-Biosensor Ag-RDTs showed excellent agreement and diagnostic performance results for samples with high viral loads (Ct≤ 25) or samples within seven d.p.o.