IntroductionCOVID 19 has been vastly spreading since December 2019 and the medical teams worldwide are doing their best to limit its spread. In the absence of a vaccine the best way to fight it is by detecting infected cases early and isolate them to prevent its spread. Therefore, a readily available, rapid, and cost-effective test with high specificity and sensitivity for early detection of COVID 19 is required. In this study, we are testing the diagnostic performance of a rapid antigen detection test in mildly symptomatic cases. (RADT).MethodsThe study included 4183 male patients who were mildly symptomatic. A nasal sample for the rapid antigen test and a nasopharyngeal sample was taken from each patient. Statistical analysis was conducted to calculate the sensitivity, specificity, positive predictive value, negative predictive value and kappa coefficient of agreement.ResultsThe prevalence of COVID 19 in the study population was 17.5% (733/4183). The calculated sensitivity and specificity were 82.1% and 99.1% respectively. Kappa’s coefficient of agreement between the rapid antigen test and RT-PCR was 0.859 (p < 0.001). A stratified analysis was performed and it showed that the sensitivity of the test improved significantly with lowering the cutoff Ct value to 24.ConclusionThe results of the diagnostic assessment of nasal swabs in the RADT used in our study are promising regarding the potential benefit of using them as a screening tool in mildly symptomatic patients. The diagnostic ability was especially high in cases with high viral load. The rapid antigen test is intended to be used alongside RT-PCR and not replace it. RADT can be of benefit in reducing the use of PCR.

IntroductionThe best way to mitigate an outbreak besides mass vaccination is via early detection and isolation of infected cases. As such, a rapid, cost-effective test for the early detection of COVID-19 is required.MethodsThe study included 4,183 mildly symptomatic patients. A nasal and nasopharyngeal sample obtained from each patient was analyzed to determine the diagnostic ability of the rapid antigen detection test (RADT, nasal swab) in comparison with the current gold-standard (RT-PCR, nasopharyngeal swab).ResultsThe calculated sensitivity and specificity of the RADT was 82.1 and 99.1%, respectively. Kappa's coefficient of agreement between the RADT and RT-PCR was 0.859 (p &lt; 0.001). Stratified analysis showed that the sensitivity of the RADT improved significantly when lowering the cut-off RT-PCR Ct value to 24.ConclusionOur study's results support the potential use of nasal swab RADT as a screening tool in mildly symptomatic patients, especially in patients with higher viral loads.