Validation and implementation of the Panbio COVID-19 Ag rapid test for the diagnosis of SARS-CoV-2 infection in symptomatic hospital healthcare workers

BACKGROUND: RT-PCR is the current recommended laboratory method to diagnose SARS-CoV-2 in healthcare workers (HCW). As RT-PCR is not widely available and is time-consuming, it limits decision making on removal from and return to work of possibly contagious HCW. AIM: In this study we evaluated the Panbio™ COVID-19 Ag rapid test (PanbioCAgRT) in 825 hospital HCW. METHODS AND FINDING: This study consisted of two phases. In the validation phase, we tested hospital HCW with mild symptoms (three days or less) in parallel using the PanbioCAgRT and the RT-qPCR test. The PanbioCAgRT demonstrated 86.7% sensitivity, 100% specificity, 100% PPV and 98.5% NPV with regard to RT-qPCR. For HCW with PanbioCAgRT-/RT-qPCR+, the median Ct value was 30.9, whereas for the HCW with PanbioCAgRT+/RT-qPCR+ the median Ct value was 19.3 (P<0.001). In the second phase, we implemented an on-site antigen test-based strategy for symptomatic hospital HCW: HCW that tested positive with the PanbioCAgRT on-site were considered SARS-CoV-2 positive and were sent home. HCW that tested negative with the PanbioCAgRT on-site were allowed to work with PPE pending RT-qPCR test results from the laboratory. Sensitivity of the antigen test-based strategy was 72.5% and NPV was 97%. For HCW with PanbioCAgRT-/RT-qPCR+ median Ct values were 27.8. CONCLUSION: The PanbioCAgRTt validated in this study showed a high sensitivity and specificity in samples obtained from HCW with high viral loads. The antigen-based testing strategy proposed in this study seems to be effective, safe and easy to implement in a wide range of occupational healthcare settings.