High performances of a novel antigen detection test on nasopharyngeal specimens for SARS-CoV-2 infection diagnosis: a prospective study
Introduction The SARS-CoV-2 pandemic has become a major public health issue worldwide. Developing and evaluating rapid and easy-to-perform diagnostic tests is an absolute priority. The current prospective study was designed to assess diagnostic performances of an antigen-based rapid detection test (COVID-VIRO) in a real-life setting. Methods Two nasopharyngeal specimens of symptomatic or asymptomatic adult patients hospitalized in the Infectious Diseases Department or voluntarily accessing the COVID-19 Screening Department of the Regional Hospital of Orleans, France, were concurrently collected. COVID VIRO diagnostic specificity and sensitivity were assessed in comparison to real-time reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) results. A subgroup of patients underwent an additional oropharyngeal and/or a saliva swab for rapid testing. Results 121 patients already having a confirmed infection and 127 patients having no evidence of recent or ongoing infection were enrolled, for a total of 248 couple of nasopharyngeal swab specimens. Overall COVID-VIRO sensitivity was 96.7% (IC: 93.5%-99.9%). In asymptomatic patients, patients having symptoms for more than 4 days and those having a RT-qPCR Cycle threshold value >32, sensitivity was of 100%, 95.8% and 96.9% respectively. The concordance between RT-qPCR and COVID VIRO rapid test was 100% for the 127 patients with no SARS-CoV-2 infection. Conclusion COVID-VIRO test had 100% specificity and above 95% sensitivity, better than WHO recommendations (specificity ≥97-100%, sensitivity ≥80%). These rapid tests are particularly interesting for large-scale screening in Emergency Department, low resource settings and airports.