Original article

Scand J Work Environ Health 2022;48(7):530-539    pdf full text

doi:10.5271/sjweh.4049 | Published online: 03 Jul 2022, Issue date: 01 Sep 2022

Healthcare workers’ SARS-CoV-2 infection rates during the second wave of the pandemic: follow-up study

by Würtz AM, Kinnerup MB, Pugdahl K, Schlünssen V, Vestergaard JM, Nielsen K, Cramer C, Bonde JP, Biering K, Carstensen O, Hansen KK, Dalbøge A, Flachs EM, Hansen ML, Thulstrup AM, Würtz ET, Kjærsgaard M, Christensen MW, Kolstad HA

Objectives This study aimed to assess if, during the second wave of the COVID-19 pandemic, healthcare workers had increased severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates, following close contact with patients, co-workers and persons outside work with COVID-19.

Methods A follow-up study of 5985 healthcare workers from Denmark was conducted between November 2020 and April 2021 and provided day-to-day information on COVID-19 contacts. SARS-CoV-2 infection was defined by the first positive polymerase chain reaction (PCR) test ever. Data was analyzed in multivariable Poisson regression models.

Results The SARS-CoV-2 infection rates following close contact 3–7 days earlier with patients, co-workers and persons outside work with COVID-19 were 153.7, 240.8, and 728.1 per 100 000 person-days, respectively. This corresponded with age, sex, month, number of PCR tests and mutually adjusted incidence rate ratios of 3.17 [40 cases, 95% confidence interval (CI) 2.15–4.66], 2.54 (10 cases, 95% CI 1.30–4.96) and 17.79 (35 cases, 95% CI 12.05–26.28). The risk of SARS-CoV-2 infection was thus lower, but the absolute numbers affected was higher following COVID-19 contact at work than COVID-19 contact off work.

Conclusions Despite strong focus on preventive measures during the second wave of the pandemic, healthcare workers were still at increased risk of SARS-CoV-2 infection when in close contact with patients or co-workers with COVID-19. There is a need for increased focus on infection control measures in order to secure healthcare workers’ health and reduce transmission into the community during ongoing and future waves of SARS-CoV-2 and other infections.

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