ABSTRACT
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.
Subject(s)
COVID-19 , InfectionsABSTRACT
Background The SARS-CoV-2 virus is responsible for the infectious respiratory disease called COVID-19 (COronaVIrus Disease). In response to the growing COVID-19 pandemic, Rapid Diagnostic Tests (RDTs) have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood. We conducted a real-life study to evaluate the performance of two RDTs, COVID-PRESTO and COVID-DUO, compared to the gold standard, RT-PCR. Methods RT-PCR testing of SARS-Cov-2 was performed from nasopharyngeal swab specimens collected in adult patients visiting the infectious disease department at the hospital (Orleans, France). Fingertip whole blood samples taken at different time points after onset of the disease were tested with RDTs. The specificity and sensitivity of the rapid test kits compared to test of reference (RT-PCR) were calculated. Results Among 381 patients with symptoms of COVID-19 who went to the hospital for a diagnostic, 143 patients were RT-PCR negative. Results of test with RDTs were all negative for these patients, indicating a specificity of 100% for both RDTs. In the RT-PCR positive subgroup (n=238), 133 patients were tested with COVID-PRESTO and 129 patients were tested with COVID-DUO (24 patients tested with both). The further the onset of symptoms was from the date of collection, the greater the sensitivity. The sensitivity of COVID-PRESTO test ranged from 10.00% for patients having experienced their 1st symptoms from 0 to 5 days ago to 100% in patients where symptoms had occurred more than 15 days before the date of tests. For COVID-DUO test, the sensitivity ranged from 35.71% [0-5 days] to 100% (> 15 days). Conclusion COVID-PRESTO and DUO RDTs turned out to be very specific (none false positive) and to be sensitive enough after 15 days from onset of symptom. These easy to use IgG/IgM combined test kits are the first ones allowing a screening with capillary blood sample, by typing from a finger prick. These rapid tests are particularly interesting for screening in low resource settings.