Open AccessA prospective study of asymptomatic SARS-CoV-2 infection among individuals involved in academic research under limited operations during the COVID-19 pandemic
Author(s) -
Audrey Pettifor,
Bethany L. DiPrete,
Bonnie Shook-Sa,
Lakshmanane Premkumar,
Kriste Kuczynski,
Dirk P. Dittmer,
Allison E. Aiello,
Shan M. Wallet,
Robert Maile,
Joyce Tan,
Ramesh Jadi,
Linda Pluta,
Aravinda M. de Silva,
David J. Weber,
Min Kim,
Arlene C. Seña,
Corbin D. Jones
Publication year - 2022
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.0267353
Subject(s) - seroconversion , asymptomatic , medicine , serology , seroprevalence , cumulative incidence , incidence (geometry) , subclinical infection , pandemic , virology , confidence interval , covid-19 , cohort study , prospective cohort study , immunology , cohort , antibody , disease , infectious disease (medical specialty) , physics , optics
Background Early in the pandemic, transmission risk from asymptomatic infection was unclear, making it imperative to monitor infection in workplace settings. Further, data on SARS-CoV-2 seroprevalence within university populations has been limited. Methods We performed a longitudinal study of University research employees on campus July-December 2020. We conducted questionnaires on COVID-19 risk factors, RT-PCR testing, and SARS-CoV-2 serology using an in-house spike RBD assay, laboratory-based Spike NTD assay, and standard nucleocapsid platform assay. We estimated prevalence and cumulative incidence of seroconversion with 95% confidence intervals using the inverse of the Kaplan-Meier estimator. Results 910 individuals were included in this analysis. At baseline, 6.2% (95% CI 4.29–8.19) were seropositive using the spike RBD assay; four (0.4%) were seropositive using the nucleocapsid assay, and 44 (4.8%) using the Spike NTD assay. Cumulative incidence was 3.61% (95% CI: 2.04–5.16). Six asymptomatic individuals had positive RT-PCR results. Conclusions Prevalence and incidence of SARS-CoV-2 infections were low; however, differences in target antigens of serological tests provided different estimates. Future research on appropriate methods of serological testing in unvaccinated and vaccinated populations is needed. Frequent RT-PCR testing of asymptomatic individuals is required to detect acute infections, and repeated serosurveys are beneficial for monitoring subclinical infection.