Comparative analysis of Real-Time PCR and Chemiluminescence for the detection of SARS-CoV-2

Abstract

SARS-CoV-2 infection is capable of causing a multi-organ syndrome, mainly involving the lungs with Acute Respiratory Insufficiency. The easy access to a rapid diagnosis of COVID-19 is a key point to improve the management of SARS-CoV-2 infection to contain its spread. The aim of this study is to evaluate the use of chemiluminescence technology in the diagnosis of SARS-CoV-2. In particular, a retrospective analysis was carried out on nasopharyngeal swabs from oncology patients referred to the National Cancer Institute of Naples, comparing the results of the Elecsys^® SARS-CoV-2 Antigen chemiluminescence assay with those obtained by molecular testing in Real Time RT-PCR. The concordance rate between the antigen test and Real Time RT-PCR was 70.83%. The false negative and false positive rates were 63.79% and 0%, respectively. Although the Elecsys® SARS-CoV-2 Antigen test showed a high specificity, it is not as sensitive as the molecular test which remains the reference method. Therefore, to compensate for the potential decrease in test sensitivity, negative results should be analysed together with more patient-related factors, such as history of exposure to COVID-19 and clinical symptoms, in order to guide the diagnosis and subsequent treatment of the patient. In the end, from a clinical point of view, the antigen test is useful for the identification of acute or early infection in a rapid and cost-effective way.