Comparing dynamics and determinants of SARS-CoV-2 transmissions among health care workers of adult and pediatric settings in central Paris

Background From the start of the pandemic, health-care workers (HCW) have paid a heavy toll to the coronavirus disease-19 (COVID-19) outbreak. Objectives To describe the dynamics and determinants of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in HCW. Design Prospective observational study conducted from February 24th until April 10th, 2020. Setting Comparison of a 1,500-bed adult and a 600-bed pediatric setting of a tertiary-care university hospital located in central Paris. Participants All symptomatic HCW screened for SARS-CoV-2 on a nasopharyngeal swab. Measurements HCW screened positive were prospectively questioned on their profession, symptoms, occupational and non-occupational exposures to SARS-CoV-2. Results Among 1344 symptomatic HCW tested, 373 were positive (28%) and 336 (90%) corresponding questionnaires were completed. Three hospitalizations and no death were reported. Most HCW (70%) had patient-facing occupational activities (22% in COVID-19 dedicated units). The total number of HCW cases peaked on March 23rd, then decreased slowly, concomitantly with a continuous increase of compliance to preventive measures (including universal medical masking and personal protective equipment (PPE) for direct care to COVID-19 patients). Attack rates were of 3.2% and 2.3% in the adult and pediatric setting, respectively (p=0.0022). In the adult setting, HCW more frequently reported exposure to COVID-19 patients without PPE (25% versus 15%, p=0.046). Report of contacts with children attending out-of-home care facilities dramatically decreased over the study period. Limitations Lack of COVID-19 negative controls and recall bias. Conclusion Universal masking, reinforcement of hand hygiene, and PPE with medical masks for patients’ care allowed protection of HCW and containment of the outbreak. Residual transmissions were related to persistent exposures with undiagnosed patients or colleagues and not to contacts with children attending out-of-home care facilities. ### Competing Interest Statement AC reports personal fees and non-financial support from Janssen Cilag, outside the submitted work. RG reports personal fees and other from Sanofi, personal fees from MSD, personal fees from Eumedica, personal fees from Pfizer, personal fees from Frezenius, personal fees from Cubist, personal fees from Correvio, personal fees from Astellas, outside the submitted work. PF reports personal fees and non-financial support from MSD France, personal fees from ViiV Healthcare, non-financial support from Gilead Science, personal fees and non-financial support from Janssen Cilag, personal fees from Medtronic SAS, non-financial support from Astellas, non-financial support from GSK, outside the submitted work. MLV reports non-financial support from Biomerieux, non-financial support from Diasorin, outside the submitted work. OL reports personal fees from Pfizer, personal fees from Astellas, personal fees from MSD, personal fees from Gilead, outside the submitted work. SK reports research grants from bioMérieux, personal fees from Accelerate Diagnostics, bioMérieux, MSD and Menarini, and travel expenses from bioMérieux, Astellas, MSD and Pfizer, outside the submitted work. All other authors declare no conflict of interests. ### Funding Statement This study had no funding source or sponsor implicated in the study design, in the collection, analysis, and interpretation of data, in the writing of the report, and in the decision to submit the article for publication. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes 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 Authors declare that all data referred in the manuscript is fully available.