Infect Control Hosp Epidemiol. 2020 Sep 23:1-25. doi: 10.1017/ice.2020.1220. Online ahead of print.
OBJECTIVE: The seroprevalence of Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-COV-2) IgG antibody was evaluated among employees of a Veterans Affairs Healthcare System to assess potential risk factors for transmission and infection.
METHODS: All employees were invited to participate in a questionnaire and serological survey to detect antibodies to SARS-CoV-2 M protein as part of a facility-wide quality improvement and infection prevention initiative regardless of clinical or non-clinical duties. The initiative was conducted from June 8 to July 8, 2020.
RESULTS: Of the 2900 employees, 50.9% participated in the study, revealing a positive SARS-COV-2 seroprevalence of 4.9% (72/1476), [95% CI of 4.04% - 5.89%]. There were no statistically significant differences in the presence of antibody based on gender, age, frontline worker status, job title, performance of aerosol generating procedures or exposure to known patients with coronavirus infectious disease 2019 (COVID-19) within the hospital. Employees who reported exposure to a known COVID-19 case outside of work had a significantly higher seroprevalence at 14.84% (23/155) compared to those that did not 3.70% (48/1296), OR 4.53 [95% CI 2.67-7.68] p<0.0001. Notably, 29% of seropositive employees reported no history of symptoms for SARS-CoV-2 infection.
CONCLUSIONS: Seroprevalence of SARS-COV-2 among employees was not significantly different among those who provided direct patient care and those who did not, suggesting facility-wide infection control measures based were effective. Employees who reported direct personal contact with COVID-19 positive persons outside of work were more likely to have SARS-CoV-2 antibodies. Employee exposure to SARS-CoV-2 outside of work may introduce infection into hospitals.