414 Population testing for COVID-19: an approach for infection prevention

<h3>Background</h3> Population screening with highly sensitive diagnostic tools, such as nucleic acid amplification testing (NAAT), can enable early identification and isolation of cases and reduce transmission of SARS-CoV-2. <h3>Objective</h3> To describe the results of a rigorous, large-scale COVID-19 testing and monitoring program with confirmatory processes and adjudication of positive results. <h3>Design</h3> Descriptive Epidemiology Study <h3>Setting</h3> 32 U.S. National Football League (NFL) Clubs during the 2020 season <h3>Participants</h3> NFL players and staff <h3>Methods</h3> The NFL/NFL Players Association instituted a COVID-19 Testing and Surveillance Program for the 2020 Season, which included daily testing for players and staff, full medical follow-up and adjudication of cases. Clinical adjudication was based on subsequent daily testing, symptoms, and clinical history; persons remained in isolation during adjudication. <h3>Results</h3> Between August 1 and November 14, 2020, a total of 632,370 RT-PCR tests were administered to 11,668 individuals; 270 (2.4%) confirmed cases were observed. PPVs of the initial positive result ranged from 73–82% across RT-PCR platforms. Initial positive results were positive on re-processing 61–79% of the time. PPV increased when both results were positive to &gt;95%; however, initial positives that were negative on confirmatory processing resulted in true cases a portion of the time, depending on machine and population prevalence. High Ct values (33 to 37) could indicate onset of infection. Infected individuals were identified and isolated early in infection, preventing spread. <h3>Interventions</h3> Daily or frequent testing using three NAAT platforms, rapid point-of-care testing, and symptom monitoring. <h3>Main Outcome Measurements</h3> COVID-19 infection. <h3>Conclusion</h3> Routine RT-PCR testing allowed early detection of infection. Cycle threshold values provided a useful guidepost for understanding results. Confirmatory processing of initial positive values significantly improved PPV. Antigen POC testing was unable to reliably rule out COVID-19 early in infection. Adjudication processes were able to confirm or rule out SARS-CoV-2.