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

Abstract

ObjectivesTo 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.MethodsA 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 χ2test for categorical variables, regression analysis was conducted to assess the associations between source type and risk of positive COVID-19 test after occupational exposure.ResultsIn 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).ConclusionOccupational 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.