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. 2022 Apr 25;17(4):e0266410.
doi: 10.1371/journal.pone.0266410. eCollection 2022.

SARS-CoV-2 seroprevalence among healthcare workers

Talia D Wiggen  1 , Bruno Bohn  1 , Angela K Ulrich  2   3 , Steven D Stovitz  4 , Ali J Strickland  3 , Brianna M Naumchik  5 , Sara Walsh  6 , Stephen Smith  6 , Brett Baumgartner  7 , Susan Kline  8 , Stephanie Yendell  9 , Craig Hedberg  3 , Timothy J Beebe  10 , Ryan T Demmer  1   11
Affiliations

SARS-CoV-2 seroprevalence among healthcare workers

Talia D Wiggen et al. PLoS One. .

Abstract

Background: Monitoring COVID-19 infection risk among health care workers (HCWs) is a public health priority. We examined the seroprevalence of SARS-CoV-2 among HCWs following the fall infection surge in Minnesota, and before and after COVID-19 vaccination. Additionally, we assessed demographic and occupational risk factors for SARS-CoV-2 infection.

Methods: We conducted two rounds of seroprevalence testing among a cohort of HCWs: samples in round 1 were collected from 11/22/20-02/21/21 and in round 2 from 12/18/20-02/15/21. Demographic and occupational exposures assessed with logistic regression were age, sex, healthcare role and setting, and number of children in the household. The primary outcome was SARS-CoV-2 IgG seropositivity. A secondary outcome, SARS-CoV-2 infection, included both seropositivity and self-reported SARS-CoV-2 test positivity.

Results: In total, 459 HCWs were tested. 43/454 (9.47%) had a seropositive sample 1 and 75/423 (17.7%) had a seropositive sample 2. By time of sample 2 collection, 54% of participants had received at least one vaccine dose and seroprevalence was 13% among unvaccinated individuals. Relative to physicians, the odds of SARS-CoV-2 infection in other roles were increased (Nurse Practitioner: OR[95%CI] 1.93[0.57,6.53], Physician's Assistant: 1.69[0.38,7.52], Nurse: 2.33[0.94,5.78], Paramedic/EMTs: 3.86[0.78,19.0], other: 1.68[0.58,4.85]). The workplace setting was associated with SARS-CoV-2 infection (p = 0.04). SARS-CoV-2 seroprevalence among HCWs reporting duties in the ICU vs. those working in an ambulatory clinic was elevated: OR[95%CI] 2.17[1.01,4.68].

Conclusions: SARS-CoV-2 seroprevalence in HCW increased during our study period which was consistent with community infection rates. HCW role and setting-particularly working in the ICU-is associated with higher risk for SARS-CoV-2 infection.

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Conflict of interest statement

Dr. Baumgartner is employed by Quansys Biosciences (Utah, USA), the manufacturer and testing site of the assays used. There are no patents, products in development, or marketed products associated with this research to declare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Figures

Fig 1
Fig 1. Study design and timeline relative to Minnesota SARS-CoV-2 infection rates.
Fig 2
Fig 2. Participant flow diagram.
Fig 3
Fig 3. SARS-CoV-2 seroprevalence by month for sample 1 and sample 2 serology testing among all participants.
Samples from February are included in the Overall group, but not presented separately due to low numbers. In sample 1 (N = 1), 0% were seropositive, in sample 2 (N = 5) 100% were seropositive. Samples with a missing date of collection are only included in the Overall group. In sample 1 (N = 10), 30% were seropositive. In sample 2 (N = 12), 25% were seropositive. %(N/total) presented above each bar.
Fig 4
Fig 4. SARS-CoV-2 seroprevalence by month for sample 1 and sample 2 serology testing among only those who were not vaccinated for COVID-19 prior to the day of serology testing.
There are 2 samples from February or without a date of collection included in the overall results. %(N/total) presented above each bar.
Fig 5
Fig 5. SARS-CoV-2 seroprevalence according to time from vaccination among vaccinated individuals.
%(N/total) presented above each bar.
See this image and copyright information in PMC

References

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