Open AccessProspective observational study and serosurvey of SARS-CoV-2 infection in asymptomatic healthcare workers at a Canadian tertiary care center
Author(s) -
Victor H Ferreira,
Andrzej Chruscinski,
Vathany Kulasingam,
Trevor J. Pugh,
Tamara Dus,
Brad Wouters,
Amit M. Oza,
Matthew Ierullo,
Terrance Ku,
Beata Majchrzak-Kita,
Sonika T. Humar,
Ilona Bahinskaya,
Natalia Pinzon,
Jianhua Zhang,
Lawrence E. Heisler,
Paul M. Krzyzanowski,
Bernard Lam,
Ilinca M. Lungu,
Dorin Manase,
Krista Pace,
Pouria Mashouri,
Michael Brudno,
Michael Garrels,
Tony Mazzulli,
Myron I. Cybulsky,
Atul Humar,
Deepali Kumar
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0247258
Subject(s) - asymptomatic , medicine , seroprevalence , context (archaeology) , cohort study , seroconversion , health care , prospective cohort study , virology , serology , immunology , human immunodeficiency virus (hiv) , antibody , biology , paleontology , economics , economic growth
Health care workers (HCWs) are at higher risk for SARS-CoV-2 infection and may play a role in transmitting the infection to vulnerable patients and members of the community. This is particularly worrisome in the context of asymptomatic infection. We performed a cross-sectional study looking at asymptomatic SARS-CoV-2 infection in HCWs. We screened asymptomatic HCWs for SARS-CoV-2 via PCR. Complementary viral genome sequencing was performed on positive swab specimens. A seroprevalence analysis was also performed using multiple assays. Asymptomatic health care worker cohorts had a combined swab positivity rate of 29/5776 (0.50%, 95%CI 0.32–0.75) relative to a comparative cohort of symptomatic HCWs, where 54/1597 (3.4%) tested positive for SARS-CoV-2 (ratio of symptomatic to asymptomatic 6.8:1). SARS-CoV-2 seroprevalence among 996 asymptomatic HCWs with no prior known exposure to SARS-CoV-2 was 1.4–3.4%, depending on assay. A novel in-house Coronavirus protein microarray showed differing SARS-CoV-2 protein reactivities and helped define likely true positives vs. suspected false positives. Our study demonstrates the utility of routine screening of asymptomatic HCWs, which may help to identify a significant proportion of infections.