Relationship of SARS-CoV-2 Antigen and Reverse Transcription PCR Positivity for Viral Cultures
Dustin W. Currie, Melisa M. Shah, Phillip P. Salvatore, Laura Ford, Melissa Whaley, Jennifer K. Meece, Lynn Ivacic, Natalie J. Thornburg, Azaibi Tamin, Jennifer L. Harcourt, Jennifer Folster, Magdalena Medrzycki, Shilpi Jain, Phili Wong, Kimberly Goffard, Douglas Gieryn, Juliana Kahrs, Kimberly Langolf, Tara Zochert, Christopher H. Hsu, Hannah L. Kirking, Jacqueline E. Tate, for the CDC COVID-19 Response Epidemiology Field Studies Team1
Abstract
A ntigen platforms for severe acute respiratory syn- drome coronavirus 2 (SARS-CoV-2) diagnostic testing have rapid turnaround time, are easy to use, and are less expensive than real-time reverse transcription PCR (RT-PCR) diagnostic testing. Using RT-PCR as the reference test, performance evaluations of the Abbott BinaxNOW COVID-19 Antigen Card Test (https:// www.abbott.com) reported a high specifi city (>98%) (1-4) but lower sensitivity, ranging from 64.2% to 89.0% for symptomatic persons (2-4) and 35.8% to 70.2% for asymptomatic persons (2,3). However, other studies have demonstrated a period of prolonged positivity for RT-PCR testing beyond which virus has been isolated (5,6). Therefore, a comprehensive examination of antigen test performance characteristics in identifying infectious persons who have SARS-CoV-2 infections requires comparison with multiple data points, including RT-PCR test positivity and the ability to isolate the virus (a marker for infectiousness) (5-7). In this study, we expand on a previous report (1) that examined performance of antigen testing relative to RT-PCR by reporting virus isolation data for persons who had positive results by antigen test or RT-PCR.