Antibodies against SARS-CoV-2 among health care workers in a country with low burden of COVID-19.

Introduction: Greece is a country with limited spread of SARS-CoV-2 and cumulative infection attack rate of 0.12% (95% CI 0.06-0.26). Health care workers (HCWs) are a well-recognized risk group for COVID-19. The study aimed to estimate the seroprevalence of antibodies to SARS-CoV-2 in a nosocomial setting and assess potential risk factors.
Methods: HCWs from two hospitals participated in the study. Hospital-1 was a tertiary university affiliated center, involved in the care of COVID-19 patients while hospital-2 was a tertiary specialized cardiac surgery center not involved in the care of these patients. A validated, CE, rapid, IgM/IgG antibody point-of-care test was used. Comparative performance with a reference globally available assay was assessed.
Results: 1,495 individuals consented to participate (response rate 77%). The anti-SARS-CoV-2 weighted prevalence was 1.26% (95% CI 0.43, 3.26) overall and 0.53% (95% CI 0.06, 2.78) and 2.70% (95% CI 0.57, 9.19) in hospital-1 and hospital-2, respectively although the study was underpowered to detect statistically significant differences. The overall, hospital-1, and hospital-2 seroprevalence was 10, 4 and 22 times higher than the estimated infection attack rate in general population, respectively. Suboptimal use of personal protective equipment was noted in both hospitals.
Conclusions: These data have implications for the preparedness of a second wave of COVID-19 epidemic, given the low burden of SARS-CoV-2 infection rate, in concordance with national projections.
Competing Interests: The study received funding from Gilead Sciences. There is a potential conflict of interest for the primary investigator, HA due to the funding received from Gilead. No other participant in the study has received funds from Gilead in any form or has been employed by Gilead. No participants have received funds for consultation services or donations or worked for any commercial company that would constitute a conflict of interest for the authors, including but not limited to Abbott and GenBody. The aforementioned competing interest does not alter our adherence to PLOS ONE policies on sharing data and materials.