Rapid Test Ag 2019-nCoV (PROGNOSIS, BIOTECH, Larissa, Greece); Performance Evaluation in Hospital Setting with Real Time RT-PCR

Introduction: Rapid antigen tests (RATs) are convenient for SARS-CoV-2 detection because they are simpler and faster than nucleic acid amplification tests (NAATs). This study aimed to assess the accuracy of a locally manufactured test; Rapid Test Ag 2019-nCoV (PROGNOSIS, BIOTECH, Larissa, Greece) in a clinical setting and during mass screening. Methods: Nasopharyngeal samples from 624 individuals were analyzed. The results of the rapid test were compared to real-time reverse-transcription quantitative polymerase chain reaction (RT-qPCR). At the end of the test’s procedure, positive test strips were scanned in an S-Flow reader in order to roughly estimate the antigen concentration. Results: The lower limit of detection of the test was 468.75 genome copies/mL. The PROGNOSIS rapid test displayed a sensitivity of 85.5% (141/165) (95%CI: 79.1–90.5) and a specificity of 99.8% (458/459) (95%CI: 98.8–100.0%). The general inter-rater agreement was 0.89 (95%CI: 85.1–93.3). The regression analysis between the S-flow reader measurements (viral antigen) and the viral load of the positive samples demonstrated a weak correlation (R(2) = 0.288, p < 0.001). Conclusion: The Rapid Test Ag 2019-nCoV demonstrated sufficient sensitivity, excellent specificity and could be available to be used with low overall cost. Thus, it could be used as point of care test, but also for mass screening for rapid detection of infected persons (e.g., for travelers).