Risk for SARS-CoV-2 infection in healthcare workers outside hospitals: A real-life immuno-virological study during the first wave of the COVID-19 epidemic

PLoS One. 2021 Sep 28;16(9):e0257854. doi: 10.1371/journal.pone.0257854. eCollection 2021.

Abstract

Objectives: Most COVID-19 related infections and deaths may occur in healthcare outside hospitals. Here we explored SARS-CoV-2 infections among healthcare workers (HCWs) in this setting.

Design: All healthcare providers in Stockholm, Sweden were asked to recruit HCWs at work for a study of past or present SARS-CoV-2 infections among HCWs. Study participants This study reports the results from 839 HCWs, mostly employees of primary care centers, sampled in June 2020.

Results: SARS-CoV-2 seropositivity was found among 12% (100/839) of HCWs, ranging from 0% to 29% between care units. Seropositivity decreased by age and was highest among HCWs <40 years of age. Within this age group there was 19% (23/120) seropositivity among women and 11% (15/138) among men (p<0.02). Current infection, as measured using PCR, was found in only 1% and the typical testing pattern of pre-symptomatic potential "superspreaders" found in only 2/839 subjects.

Conclusions: Previous SARS-CoV-2 infections were common among younger HCWs in this setting. Pre-symptomatic infection was uncommon, in line with the strong variability in SARS-CoV-2 exposure between units. Prioritizing infection prevention and control including sufficient and adequate personal protective equipment, and vaccination for all HCWs are important to prevent nosocomial infections and infections as occupational injuries during an ongoing pandemic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • COVID-19 / epidemiology*
  • COVID-19 / transmission*
  • Female
  • Health Personnel / trends*
  • Hospitals
  • Humans
  • Male
  • Middle Aged
  • Pandemics / prevention & control
  • Personal Protective Equipment
  • Risk Factors
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / pathogenicity
  • Sweden / epidemiology

Grants and funding

This work was supported by the Karolinska University Hospital (KUH); the County Council of Stockholm; Erling-Persson family foundation; KTH Royal Institute of Technology; Creades and SciLifeLab. Role of funder was as employer of the study team, providing facilities and resources (KUH, KTH and SciLifeLab) and also assisted with enrolment (KUH). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.