SARS-CoV-2 infection among healthcare workers in a hospital in Madrid, Spain

Abstract

Background: Healthcare workers (HCWs) are especially vulnerable to infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Aim: The aim of this study was to describe the epidemiological and clinical characteristics of coronavirus disease 2019 (COVID-19) among HCWs from February 24^th to April 30^th, 2020, in a hospital in Madrid, Spain.

Methods: This was a retrospective cohort study. Cumulative COVID-19 incidence was calculated for all HCWs and categorized according to presumed level of COVID-19 exposure (high, medium, and low).

Findings: Among 1911 HCWs, 213 (11.1%) had COVID-19 during the study period. Cases increased gradually from March 8^th, peaking on March 17^th and declining thereafter. The peak of cases among HCWs was reached 14 days before the peak in admitted COVID-19 cases in the hospital. There were no significant differences in the proportion of COVID-19 cases according to level of occupational exposure (P = 0.123). There were five departments and two professions in which >20% of the workers had confirmed COVID-19. Temporal clusters were identified in three of these departments and one profession, with most of the cases occurring over a period of less than five days. The prevalence of comorbidities was low and 91.5% of patients had mild or moderate symptoms. Eleven patients were admitted to the hospital and one patient needed intensive care. None of the patients died. The median time of sick leave was 20 (interquartile range: 15-26) days.

Conclusion: The results suggest that HCW-HCW transmission accounted for part of the cases. In spite of a low prevalence of comorbidities and a mild clinical course in most cases, COVID-19 caused long periods of sick leave.

Keywords: COVID-19; Health personnel; Hospital infections; Infection control.

Figure 1

Number of healthcare workers with confirmed COVID-19 by day of presentation to the clinic (blue bars). The number of patients with COVID-19 who were admitted to the hospital for the study period (A, green line) and the number of microbiologically confirmed reported cases in the Madrid Autonomous Region (MAR) (B, orange line) are also shown. Weekend days (Saturday and Sunday) are March 7^th–8^th, 14^th–15^th, 21^st–22^nd and 28^th–29^th, and April 4^th–5^th, 11^th–12^th, 18^th–19^th, 25^th–26^th. One patient with COVID-19 who stayed in the hospital from February 24^th to 28^th is not shown in (A). HCWs, healthcare workers.

Figure 2

Number of cases according to date of presentation for the departments (A) and professions (B) with more than 10 HCWs and in which more than 20% of the HCWs had COVID-19.