Denise J McCulloch1, Michael L Jackson2, James P Hughes3, Sandra Lester4, Lisa Mills5, Brandi Freeman6, Mohammad Ata Ur Rasheed4, Natalie J Thornburg6, Helen Y Chu1. 1. School of Medicine, University of Washington, Seattle, Washington, United States of America. 2. Kaiser Permanente Washington, Seattle, Washington, United States of America. 3. Department of Biostatistics, School of Public Health, University of Washington, Seattle, Washington, United States of America. 4. Synergy America, Inc., Duluth, Georgia, United States of America. 5. Eagle Global Scientific, LLC, Atlanta, Georgia, United States of America. 6. Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
Abstract
BACKGROUND: The first US case of SARS-CoV-2 infection was detected on January 20, 2020. However, some serology studies suggest SARS-CoV-2 may have been present in the United States prior to that, as early as December 2019. The extent of domestic COVID-19 detection prior to 2020 has not been well-characterized. OBJECTIVES: To estimate the prevalence of SARS-CoV-2 antibody among healthcare users in the greater Seattle, Washington area from October 2019 through early April 2020. STUDY DESIGN: We tested residual samples from 766 Seattle-area adults for SARS-CoV-2 antibodies utilizing an ELISA against prefusion-stabilized Spike (S) protein. RESULTS: No antibody-positive samples were found between October 2, 2019 and March 13, 2020. Prevalence rose to 1.2% in late March and early April 2020. CONCLUSIONS: The absence of SARS-CoV-2 antibody-positive samples in October 2019 through mid-March, 2020, provides evidence against widespread circulation of COVID-19 among healthcare users in the Seattle area during that time. A small proportion of this metropolitan-area cohort had been infected with SARS-CoV-2 by spring of 2020.
BACKGROUND: The first US case of SARS-CoV-2 infection was detected on January 20, 2020. However, some serology studies suggest SARS-CoV-2 may have been present in the United States prior to that, as early as December 2019. The extent of domestic COVID-19 detection prior to 2020 has not been well-characterized. OBJECTIVES: To estimate the prevalence of SARS-CoV-2 antibody among healthcare users in the greater Seattle, Washington area from October 2019 through early April 2020. STUDY DESIGN: We tested residual samples from 766 Seattle-area adults for SARS-CoV-2 antibodies utilizing an ELISA against prefusion-stabilized Spike (S) protein. RESULTS:No antibody-positive samples were found between October 2, 2019 and March 13, 2020. Prevalence rose to 1.2% in late March and early April 2020. CONCLUSIONS: The absence of SARS-CoV-2 antibody-positive samples in October 2019 through mid-March, 2020, provides evidence against widespread circulation of COVID-19 among healthcare users in the Seattle area during that time. A small proportion of this metropolitan-area cohort had been infected with SARS-CoV-2 by spring of 2020.
Authors: Rachel E Geyer; Jack Henry Kotnik; Victoria Lyon; Elisabeth Brandstetter; Monica Zigman Suchsland; Peter D Han; Chelsey Graham; Misja Ilcisin; Ashley E Kim; Helen Y Chu; Deborah A Nickerson; Lea M Starita; Trevor Bedford; Barry Lutz; Matthew J Thompson Journal: JMIR Public Health Surveill Date: 2022-02-22