Rapid Antigen Tests for COVID-19: Are Their Specificity, Sensivity and Accuracy Sufficient?

Abstract

Objective: The aim of our study was to determine the sensitivity and specificity of rapid antigen and Real-Time Polymerase Chain Reaction (RT-PCR) tests which are widely used today in patients presenting with Covid-19 complaints and to evaluate these tests’ routine usability.
 
 Methods: Two samples were taken from oropharyngeal and nasopharyngeal from 100 patients (50 women, 50 men) who applied to the Covid-19 outpatient clinic of our hospital between April and May 2022. The patients attended to the study were volunteers between the ages of 18-90. One of the samples was studied with the BNG SARS-CoV-2 Antigen Rapid Test (Saliva) and evaluated with the naked eye after 15 minutes according to the company's recommendations. The other sample was studied with RT-PCR on BIO-RAD CFX Real Time System with DSCoronex Covid-19 QPCR Test Kit. The epidemiological data and clinical conditions of the patients were determined by questionnaires. The age, gender, symptoms (fever, cough, headache, diarrhea, sore throat, shortness of breath, loss of taste and smell, myalgia) of the patient and the day of the symptoms were questioned.
 
 Results: The median age was 41.5 (19-85). Thirty-four (34%) patients who applied with Covid-19 complaints were found to be PCR positive. Of 34 patients with positive PCR, 24 (71%) were also positive by rapid antigen test, and 10 (29.4%) were found to be negative.
 
 Conclusion: It is known that rapid antigen tests generally have lower sensitivity and higher specificity than RT-PCR. In our study, the sensitivity was 71% and the specificity was 100%. The Accuracy (Diagnostic Value) rate of the rapid antigen test results we used was determined as 90%. Our results suggest that rapid antigen tests are inexpensive and practical tests to reduce transmission, especially in epidemics to control the epidemic with rapid isolation.