Optimizing sars-cov-2 surveillance in the united states: Insights from the national football league occupational health program

Christina DeFilippo Mack, Michael Osterholm, Erin B. Wasserman, Natalia Petruski-Ivleva, Deverick J. Anderson, Emily Myers, Navdeep Singh, Patti Walton, Gary Solomon, Christopher Hostler, Jimmie Mancell, Allen Sills

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


Background: Evidence to understand effective strategies for surveillance and early detection of SARS-CoV-2 is limited. Objective: To describe the results of a rigorous, large-scale COVID-19 testing and monitoring program. Design: The U.S. National Football League (NFL) and the NFL Players Association (NFLPA) instituted a large-scale COVID-19 monitoring program involving daily testing using 2 reverse transcription polymerase chain reaction (RT-PCR) platforms (Roche cobas and Thermo Fisher QuantStudio), a transcriptionmediated amplification platform (Hologic Panther), and an antigen point-of-care (aPOC) test (Quidel Sofia). Setting: 32 NFL clubs in 24 states during the 2020 NFL season. Participants: NFL players and staff. Measurements: SARS-CoV-2 test results were described in the context of medically adjudicated status. Cycle threshold (Ct) values are reported when available. Results: A total of 632 370 tests administered across 11 668 persons identified 270 (2.4%) COVID-19 cases from 1 August to 14 November 2020. Positive predictive values ranged from 73.0% to 82.0% across the RT-PCR platforms. High Ct values (33 to 37) often indicated early infection. For the first positive result, the median Ct value was 32.77 (interquartile range, 30.02 to 34.72) and 22% of Ct values were above 35. Among adjudicated COVID-19 cases tested with aPOC, 42.3% had a negative result. Positive concordance between aPOC test result and adjudicated case status increased as viral load increased. Limitations: Platforms varied by laboratory, and test variability may reflect procedural differences. Conclusion: Routine RT-PCR testing allowed early detection of infection. Cycle threshold values provided a useful guidepost for understanding results, with high values often indicating early infection. Antigen POC testing was unable to reliably rule out COVID-19 early in infection.

Original languageEnglish (US)
Pages (from-to)1081-1089
Number of pages9
JournalAnnals of internal medicine
Issue number8
StatePublished - Aug 1 2021

Bibliographical note

Funding Information:
Protocols, program conduct, operations, analytics, and manuscript preparation for this COVID-19 monitoring program were funded by the NFL/NFLPA.

Publisher Copyright:
© 2021 American College of Physicians. All rights reserved.


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