Comparative field study of Rapid-Antigen Detection (RAD) with Multiplex Real Time-PCR for COVID-19 diagnosis

Abstract

RT-PCR is a gold standard test for the diagnosis of SARS-CoV2 (Covid-19) infection; however, it is an expensive, time consuming and technical demanding technique. Rapid antigen detection immunoassay (RAD) is cost-effective, quick as well as can be performed and interpreted easily. The rapid diagnosis of COVID-19 patients is essential to reduce cost and control the disease spread; however, the real world data of these tests must be validated with RT-PCR before they can be used at large scale. The objective of this study was to determine the sensitivity and specificity of PanbioTMCOVID-19 Ag-Rapid test device (Abbot) with multiplex RT-PCR. METHODS: A total of n=3509 samples were tested for SARS-CoV-2 RAD and RT-PCR at Institute of Biomedical and Genetic Engineering, Islamabad. The rapid antigen tests were performed by PanbioTMCOVID-19 Ag-Rapid test device (Abbott) and compared with RT-PCR performed on Thermo Fisher (ABI) Quant Studio 5 using CDC 2019-nCoV RT-PCR protocol. RESULTS: Total (n=3509), n=458 (7.60%) samples were reported positive by rapid antigen out of which n= 445 RT-PCR positive (13 false positive by rapid antigen), n=3051 (92.4%) were negative. True antigen negative tests n= 3051) were repeated with RT-PCR among these, n=25 were observed RT-PCR positive (rapid antigen false negative). The threshold cycle (CT) for the RT-PCR tests of these samples was >30. CONCLUSION: PanbioTMCOVID-19 Ag-Rapid test devices (Abbott) showed a sensitivity ratio 94.6% compared to RT-PCR. The PanbioTMCOVID-19 Ag-Rapid test device (Abbott) is reliable and can be used for screening and isolation of positive patients from the population.