SARS-CoV-2 seroprevalence and asymptomatic viral carriage in healthcare workers: a cross-sectional study

Original: Thorax 2020; 11 September 2020

Author(s): Shields A, Faustini SE, Perez-Toledo M et al.

Reviewer: Stylianos Loukides, e-Learning Director

Published: 18 Oct, 2020

Healthcare workers are susceptible to SARS-COV-2 infection. Previously published data supports increased infection rates either in symptomatic or/and asymptomatic individuals. The above rates are predominately occurred in symptomatic individuals and are considered higher compared to general population. We are still questioning ourselves whether any existed antibody responses are associated with immunity. Furthermore, we are still unaware of how long antibody titers will be maintained.

The current cross sectional study wanted to determine the prevalence of infection and seroprevalence of SARS-CoV-2 antibodies in healthcare workers and their relationship to prior symptoms of COVID-19. Additionally, to analyze the hospital departments in which participants worked.

545 individuals were recruited. Patients symptomatic on the day of recruitment as well as those isolated at home with symptoms compatible to SARS COV-2 were excluded.
Participants were asked to retrospectively report any illnesses consistent with COVID-19 that they had suffered in the previous 4 months. Ethnodemographic data and their department of work were also recorded.

The whole prevalence of SARS-CoV-2 viral carriage was 2.4% (n=13/545). The overall seroprevalence of SARS-CoV-2 antibodies was 24.4% (n=126/516). Those participants who were reported symptomatic had had higher seroprevalence (37.5% vs 17.1%, p<0.0001) Seroprevalence was greatest among those working in housekeeping (34.5%), acute medicine (33.3%) and general internal medicine (30.3%), with lower rates observed in participants working in intensive care (14.8%). Black Asian and minority ethnic people were at increased risk. Women had a higher seroprevalence than men but the above difference did not reach statistical significance.

The study showed increased seroprevalence among health care workers. This rate was mainly related to the underline ethnicity as well as to the the hospital departments in which participants worked. The latest showed a protective enviroment for those working in ICU.

The study confirms the occupational risk and raises a significant point for helathcare workers: The measurement of seroprevalence must be a routine assessment for people who are working at health facilities.

Respiratory digests
Respiratory infections