Professional practice for COVID-19 risk reduction among health care workers : a Cross-Sectional Study with Matched Case-Control Comparison

WILSON, S.; MOUET, A.; JEANNE-LEROYER, C.; BORGEY, F.; ODINET-RAULIN, E.; HUMBERT, X.; LE HELLO, S.; THIBON, P.

Abstract Background: Health care workers (HCWs) are particularly exposed to COVID-19 and therefore it is paramount to study preventive measures in this population. Aim: To investigate socio-demographic factors and professional practice associated with the risk of COVID-19 among HCWs in health establishments in Normandy, France Methods: A cross-sectional and 3 case-control studies were conducted in order to explore the possible risk factors that lead to SARS-CoV2 transmission within HCWs, based on an online questionnaire. The case-control studies focused on risk factors associated with care of COVID-19 patients, care of non COVID-19 patients and contacts between colleagues. Findings: Among 2,058 respondents, respectively 1,363 (66.2%) and 695 (33.8%) in medical and medico-social establishments, 301 (14.6%) reported having been infected by SARS-CoV2. When caring for COVID-19 patients, HCWs who declared wearing respirators, either for all patient care (ORa 0.39; 95% CI: 0.29-0.51) or only when exposed to aerosol-generating procedures (ORa 0.56; 95% CI: 0.43-0.70), had a lower risk of infection compared with HCWs who declared wearing mainly surgical masks. During care of non COVID-19 patients, wearing mainly a respirator was associated with a higher risk of infection (ORa 1.84; 95% CI: 1.06-3.37). An increased risk was also found for HCWs who changed uniform in workplace changing rooms (ORa 1.93; 95% CI: 1.63-2.29). Conclusion: Correct use of PPE adapted to the situation and risk level is essential in protecting HCWs against infection.