Incidence of unknown COVID-19 infection in a cohort of emergency physicians and advance practice providers

Nathan Barksdale Aaron Nathan Barksdale, Macy G. Wood, Chad E. Branecki, Brooklin Zimmerman, Elizabeth Lyden, Thang T. Nguyen, Andrew Hatfield, Scott Koepsell, Jason Langenfeld, Wesley G. Zeger, Michael C. Wadman

Research output: Contribution to journalArticlepeer-review


Introduction: In United States, health care workers have been immersed in the COVID-19 pandemic since February 2020. Since availability of COVID-19 vaccines, there is limited literature investigating the incidence of unknown COVID-19 infections in physicians and Advanced Practitioner Providers (APPs) working in emergency departments (EDs). The primary objective is to determine the incidence unknown COVID-19 infection within a cohort of emergency physicians (EPs) and APPs. Methods: Prospective observational study at a tertiary academic center with emergency medicine residency and 64,000 annual ED visits. EPs/APPs providing care to ED patients over the prior 12 months were eligible. Serum samples were collected between May 1 and June 30, 2022. Analysis utilized Luminex xMAP® SARS-CoV-2 Multi-Antigen IgG Assay for antibodies to Nucleocapsid, Receptor-binding domain, and Spike subunit 1. Mean Fluorescent Intensity (MFI) ≥ 700 was considered positive. Subjects completed 12 question survey assessing demographics and previously confirmed COVID-19 infection. Fisher's exact test evaluated associations of demographics and clinical characteristics with confirmed COVID-19 status. Analyses performed using SAS, Version 9.4. P < 0.05 considered statistically significant. Results: Sixty-nine of 81 eligible subjects (85.2%) participated, 58.0% were male, 97.1% white, with mean age of 37. Eighteen subjects had MFI ≥ 700 strongly suggestive of prior infection, with 17.7% unknown. No statistically significant difference between age, gender, race, children in home, or household member with previously COVID-19 infection. Conclusion: Unknown previous COVID-19 infection was less then expected in this cohort of EPs/APPs, and no association with individual characteristics, previously infected household member, or children in the home.

Original languageEnglish (US)
Pages (from-to)155-160
Number of pages6
JournalAmerican Journal of Emergency Medicine
StatePublished - Feb 2023


  • Antibodies
  • COVID-19
  • Emergency medicine
  • Infection
  • SARS-CoV-2

ASJC Scopus subject areas

  • Emergency Medicine


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