Epidemiological and bacteriological trends from 2013 to 2023 of carbapenemase-producing enterobacterales (CPE) in a French university hospital: A permanent risk of outbreak.

Aim: The aim of this study was to describe the epidemiology and bacteriological trends of carbapenemase-producing Enterobacteriaceae (CPE) at Nantes University Hospital from 2013 to 2023.

Methods: Potential CPE carriers were prospectively detected, and their contacts were systematically screened for CPE digestive colonization. A retrospective study was conducted from 2013 to 2023 (on patient characteristics) and from 2016 to 2023 (on CPE characteristics). An outbreak was defined as at least one secondary case occurring among contact patients during the same hospitalization, in the same unit, and with the same staff.

Results: All in all, 553 CPE-positive carriers were identified during the study period. Among them, 178 (32 %) were sporadic cases and 100 (18 %) were incidentally detected. Fifty-seven outbreaks were investigated comprising 305 (55 %) secondary cases. The most commonly identified CPE species in outbreaks were Klebsiella pneumonia OXA-48.

Conclusion: CPE detection in the hospital was associated mainly with epidemic spread involving a variable number of secondary cases. CPE patients detected incidentally (without specific infection control measures) several days after hospital admission, repatriates and patients with a history of hospitalization abroad are at high risk of in-hospital CPE spread. The number of outbreaks did not decrease during the study period, and more generally, the number of secondary cases tends in some uncontrolled situations to increase, particular when CPE- positive patients are transferred or rehospitalized.