The prevalence of antibodies to SARS CoV 2 in asymptomatic healthcare workers with intensive exposure to COVID 19

The prevalence of asymptomatic SARS-CoV-2 infection in healthcare workers with intensive exposure to COVID-19 is unclear. In this study, we investigated the seroprevalence of SARS-CoV-2 in 797 asymptomatic healthcare workers with intensive exposure to COVID-19 patients in Wuhan, China. Positive IgG was detected from 35 asymptomatic healthcare workers, and the prevalence of antibodies to SARS-CoV-2 in asymptomatic healthcare workers was 4.39% (35/797). None of them developed COVID-19 until May 15. 33 of them have performed at least one chest CT scan showing no viral pneumonia features, and 16 have finished at least one-time SARS-CoV-2 RNA detection with negative results. When contacting with the patients, 15 of them dressed with full personal protective equipment (PPE), and 16 worn N95 mask and gown. To the best of our knowledge, this is the first investigation reported that the seroprevalence of SARS-CoV-2 was 4.39% in asymptomatic healthcare workers with applied PPE in a high epidemic area, which may provide useful information of estimating asymptomatic infection rate in general population. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was partly supported by the National Science and Technology Major Project for Infectious Diseases of China (2017ZX10304402-002-005, 2018ZX10723203, 2018ZX10302206), HUST COVID-19 Rapid Response Call (2020kfyXGYJ046, 2020kfyXGYJ016), and the Medical Faculty of the University of Duisburg-Essen and Stiftung Universitaetsmedizin, University Hospital Essen, Germany. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: We obtained written informed consent from the participants and this study was approved by medical ethics committee of Union Hospital, Huazhong University of Science and Technology (0056). All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.