Seroprevalence of SARS‐CoV‐2 antibodies among rural healthcare workers

The objective of this longitudinal cohort study was to determine the seroprevalence of antibodies to severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) in healthcare workers employed at healthcare settings in three rural counties in eastern South Dakota and western Minnesota from May 13, 2020, through December 22, 2020. Three blood draws were performed at five clinical sites and tested for the presence of antibodies against the SARS‐CoV‐2. Serum samples were tested for the presence of antibodies using a fluorescent microsphere immunoassay (FMIA), neutralization of SARS‐CoV‐2 spike‐pseudotyped particles (SARS‐CoV‐2pp) assay, and serum virus neutralization (SVN) assay. The seroprevalence was determined to be 1/336 (0.29%) for samples collected from 5/13/20 to 7/13/20, 5/260 (1.92%) for samples collected from 8/13/20 to 9/25/20, and 35/235 (14.89%) for samples collected from 10/16/20 to 12/22/20. Eight of the 35 (22.8%) seropositive individuals identified in the final draw did not report a previous diagnosis with COVID‐19. There was a high correlation (>90%) between the FMIA and virus neutralization assays. Each clinical site's seroprevalence was higher than the cumulative incidence for the general public in the respective county as reported by state public health agencies. As of December 2020, there was a high percentage (85%) of seronegative individuals in the study population.

[1]  M. Breteler,et al.  Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany , 2021, Nature Communications.

[2]  S. S. Sohrab,et al.  Seroprevalence of neutralizing antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers in Makkah, Saudi Arabia , 2021, Journal of King Saud University - Science.

[3]  C. Donnelly,et al.  SARS-CoV-2 antibody prevalence in England following the first peak of the pandemic , 2021, Nature Communications.

[4]  D. Qu,et al.  Enhancement versus neutralization by SARS-CoV-2 antibodies from a convalescent donor associates with distinct epitopes on the RBD , 2021, Cell Reports.

[5]  N. Rosenthal,et al.  Risk Factors Associated With In-Hospital Mortality in a US National Sample of Patients With COVID-19 , 2020, JAMA network open.

[6]  Pui Ying Chan,et al.  COVID-19 Outbreak — New York City, February 29–June 1, 2020 , 2020, MMWR. Morbidity and mortality weekly report.

[7]  J. Löndahl,et al.  Exhaled respiratory particles during singing and talking , 2020, Aerosol Science and Technology.

[8]  B. Farber,et al.  Prevalence of SARS-CoV-2 Antibodies in Health Care Personnel in the New York City Area. , 2020, JAMA.

[9]  Nicole M. Bouvier,et al.  The coronavirus pandemic and aerosols: Does COVID-19 transmit via expiratory particles? , 2020, Aerosol science and technology : the journal of the American Association for Aerosol Research.

[10]  Yan Liu,et al.  Characterization of spike glycoprotein of SARS-CoV-2 on virus entry and its immune cross-reactivity with SARS-CoV , 2020, Nature Communications.

[11]  D. Cucinotta,et al.  WHO Declares COVID-19 a Pandemic , 2020, Acta bio-medica : Atenei Parmensis.

[12]  N. Dey.  COVID-19 Outbreak , 2020, Data Analytics for Pandemics.

[13]  A. M. Leontovich,et al.  The species Severe acute respiratory syndrome-related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2 , 2020, Nature Microbiology.

[14]  Rural-Urban Continuum Codes 2013 , 2020, Definitions.

[15]  S. Lindstrom,et al.  First Case of 2019 Novel Coronavirus in the United States , 2020, The New England journal of medicine.

[16]  G. Gao,et al.  A Novel Coronavirus from Patients with Pneumonia in China, 2019 , 2020, The New England journal of medicine.

[17]  C. Viboud,et al.  Urbanization and humidity shape the intensity of influenza epidemics in U.S. cities , 2018, Science.

[18]  T. Clement,et al.  Pathogenesis of Senecavirus A infection in finishing pigs. , 2016, The Journal of general virology.

[19]  F. Lardeux,et al.  Calculation of the ELISA’s cut-off based on the change-point analysis method for detection of Trypanosoma cruzi infection in Bolivian dogs in the absence of controls , 2016, Memorias do Instituto Oswaldo Cruz.

[20]  T. Clement,et al.  Development of monoclonal antibodies and serological assays including indirect ELISA and fluorescent microsphere immunoassays for diagnosis of porcine deltacoronavirus , 2016, BMC Veterinary Research.

[21]  Jane Christopher-Hennings,et al.  Development of an indirect ELISA, blocking ELISA, fluorescent microsphere immunoassay and fluorescent focus neutralization assay for serologic evaluation of exposure to North American strains of Porcine Epidemic Diarrhea Virus , 2015, BMC Veterinary Research.

[22]  A. Mishra,et al.  Health Status and Health Care Access of Farm and Rural Populations , 2012 .

[23]  A. Kittawornrat,et al.  Development of a Fluorescent Microsphere Immunoassay for Detection of Antibodies against Porcine Reproductive and Respiratory Syndrome Virus Using Oral Fluid Samples as an Alternative to Serum-Based Assays , 2011, Clinical and Vaccine Immunology.

[24]  J. Lunney,et al.  Development of an 8-plex Luminex assay to detect swine cytokines for vaccine development: assessment of immunity after porcine reproductive and respiratory syndrome virus (PRRSV) vaccination. , 2010, Vaccine.

[25]  P. Yaswen,et al.  A Versatile Viral System for Expression and Depletion of Proteins in Mammalian Cells , 2009, PloS one.