Coworkers are more likely than patients to transmit SARS-CoV-2 infection to healthcare personnel

Occup Environ Med. 2022 Oct;79(10):713-716. doi: 10.1136/oemed-2022-108276. Epub 2022 Aug 4.


Objectives: To compare the impact of occupational exposures to SARS-CoV-2 positive patients and SARS-CoV-2 positive coworkers, by comparing the frequency of occupational exposure incidents and the rate of healthcare personnel (HCP) who developed a positive PCR test for SARS-COV-2 after occupational exposure to the two different types of infectious individuals.

Methods: A retrospective analysis of all confirmed higher risk occupational exposure incidents that occurred in HCP from 20 March 2020 to 31 December 2020 at a large multisite US academic medical centre. Comparisons between groups for source type were performed using unpaired Student's t-test for continuous variables and the χ2 test for categorical variables, regression analysis was conducted to assess the associations between source type and risk of positive COVID-19 test after occupational exposure.

Results: In total, 2253 confirmed medium or high-risk occupational exposures occurred during the study period. 57% were exposures from coworker sources. Each source individual exposed a mean of 2.6 (95% CI 2.3 to 2.9) HCP; during postexposure surveillance, 4.5% of exposed HCP tested positive within 14 days. A coworker source on average exposed 2.2 (95% CI 2.01 to 2.4) other HCP and infected 0.14 (95% CI 0.1 to 0.17) HCP, while patient sources exposed a mean of 3.4 (95% CI 2.6 to 4.2) HCP but only infected 0.07 (95% CI 0.04 to 0.11) HCP. The multivariate analysis demonstrated that exposure to a coworker source carried a higher risk of testing positive compared with exposure to a patient source (OR 3.22; 95% CI 1.72 to 6.04).

Conclusion: Occupational exposures to coworker sources were not only more frequent but also associated with triple the risk of developing COVID-19 infection, compared with exposures to patient sources.

Keywords: COVID-19; Healthcare personnel; Occupational exposures; SARS-CoV-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / epidemiology
  • Delivery of Health Care
  • Health Personnel
  • Humans
  • Retrospective Studies
  • SARS-CoV-2