Key Points

Monitoring of reports of nosocomial COVID-19 cases, e-SIN, France, from March 1, 2020, to November 28, 2022

• 77.7% of reports received since the start of the epidemic corresponded to clusters of cases (CG).

• 10: the median number of cases per outbreak.

• 33% of healthcare professionals involved in HCUs throughout the epidemic, a figure that has been gradually declining since 2020.

• The source of nosocomial CG is predominantly a patient (56%).

The two most frequently cited hypotheses to explain transmission are the failure to identify a case upon admission (41%) and breaches in the application of infection control measures (42%), particularly during patient care and when receiving families/visitors.