Healthcare workers' SARS-CoV-2 infection rates during the second wave of the pandemic: prospective cohort study

ObjectivesTo assess if healthcare workers during the second wave of the COVID-19 pandemic had increased SARS-CoV-2 infection rates following close contact with patients, co-workers and persons outside work with COVID-19. DesignProspective cohort study. SettingPublic hospital employees in Denmark. Participants5985 healthcare workers (88.6% women) who daily on a smartphone reported COVID-19 contact. Main outcome measuresSARS-CoV-2 infection rates defined by the first positive polymerase chain reaction (PCR) test recorded in a register with complete test coverage. Results159 positive and 35 996 negative PCR tests for SARS-CoV-2 were recorded during 514 165 person-days of follow-up November 25, 2020 - April 30, 2021. The SARS-CoV-2 infection rate for healthcare workers who during the previous 3-7 days had close contact with COVID-19 patients was 153.7 per 100 000 person-days (0.15% per day) corresponding with an incidence rate ratio of 3.17 (40 cases, 95% CI 2.15 to 4.66) when compared with no close contact with COVID-19 patients. SARS-CoV-2 incidence rate ratios following close contact with co-workers and persons outside work with COVID-19 were 2.54 (10 cases, 95% CI 1.30 to 4.96) and 17.79 (35 cases, 95% CI 12.05 to 26.28). These estimates were mutually adjusted and further adjusted for age, sex, month and number of previous PCR tests. ConclusionsDespite strong focus on preventive actions 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 with COVID-19. The numbers affected were comparable to the numbers affected following COVID-19 contact outside work. Close contact with co-workers was also a risk factor. This stresses the need for increased focus on preventive actions to secure healthcare workers health during ongoing and future waves of SARS-CoV-2 and other infections. Summary boxO_ST_ABSWhat is already known on this topic?C_ST_ABSDuring the first wave of the COVID-19 pandemic, preventive measures were inadequate and healthcare workers were at increased risk of SARS-CoV-2 infection. What this study adds?During the second wave of the pandemic, despite a strong focus on preventive actions, healthcare workers were still at increased risk of SARS-CoV-2 infection following close contact with COVID-19 patients. The numbers affected were comparable to the numbers affected following COVID-19 contact outside work. Healthcare works were also at increased risk following close contact with co-workers.