SARS-CoV-2 Rapid Antigen Detection in Respiratory and Nonrespiratory Specimens in COVID-19 Patients

Abstract

Rapid antigen testing for coronavirus disease 2019 (COVID-19) available at present provides immediate results at low cost with less expertise and without any need of sophisticated infrastructure. Most of these test kits available are for nasopharyngeal samples. This is a novel study to detect the presence of COVID antigen in samples other than throat and oropharyngeal. Various samples received from patients admitted in the COVID-19 dedicated center were tested for the presence of antigen. Same procedure was followed as done for the nasopharyngeal sample. A total of 150 samples were tested, which included ascitic fluid, pleural fluid, drain fluid, bile, bronchoalveolar lavage, cerebrospinal fluid, endotracheal tube aspirate, sputum, tissue, and urine. Out of 150, 11 (7.33%) were positive and 138 (92.66%) were negative for the antigen test. The COVID-19 antigen test kit, though designed for nasopharyngeal samples, was able to detect the presence of antigen in other clinical samples.