McCulloch DJ, Jackson ML, Hughes JP, Lester S, Mills L, Freeman B, Rasheed MAU, Thornburg NJ, Chu HY. Seroprevalence of SARS-CoV-2 antibodies in Seattle, Washington: October 2019-April 2020.
PLoS One 2021;
16:e0252235. [PMID:
34043706 PMCID:
PMC8158900 DOI:
10.1371/journal.pone.0252235]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/11/2021] [Indexed: 12/24/2022] Open
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.
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