Accuracy of Roche SARS-CoV-2 Rapid Antigen Test in Nasopharyngeal Swab: Clinical Impression Matters

Background: In COVID-19 pandemic, the diagnosis and treatment must be as early possible to save life of each patient. Moreover, screening asymptomatic carriers, close contacts or healthy subjects not delay prevent transmission publics. For confirmation SARS-CoV-2 infection, nasopharyngeal swab tested either by real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) tests Rapid Antigen Test (RAT). RAT is faster, easier cheaper; thus, it suitable for health service in developing country. Objectives: The aim this study was assess diagnostic accuracy Roche (RAT) diagnosing infection. Methods: Hospital based exploratory done out-patient department fever clinic, molecular laboratory No. (1) Defence Services General Hospital. Nasopharyngeal swabs were taken, SARS- CoV-2 conducted parallel with RT-PCR test (reference standard). Results: Among 932 patients/subjects recruited, positive 468 individuals, corresponding a prevalence 50.2%. 363 patients (60.4%), false 120 patients; negative 569 individuals (39.6%), 225 patients. overall sensitivity 51.9% (95% Confidence Interval [CI] 47.29-56.53) and, specificity 74.1% CI 69.9-78.07); predictive value 66.9% 60.5%. varied Ct value; 78% clinical samples values < 20, 57.5% those between 21 25, 41.8% 26 30, 36.4% > 30. Conclusion: infections inferior manufacturer’s data. low Cycle threshold 20 which inversely related viral load. should used association impression physicians. hospital setting especially emergency department, role reconsidered presenting anosmia some cases dyspnoea, late symptoms course disease, results would negative. Other errors may arise if operator has handle more than recommended per hour peak epidemics.