1g - An outbreak of carbapenemase-producing Enterobacterales (CPE) in a new-build single bed-room specialist cardiothoracic hospital in England, 2024

Background : Globally, hospitals are experiencing increases in CPE (carbapenemase-producing Enterobacterales) bacteria that can cause antibiotic-resistant infections. Investigation into a CPE outbreak at a new-build single-bed-ward cardiothoracic hospital in England occurred after the detection of two clinical cases. Understanding transmission dynamics and the impact of control measures is crucial for preparation for increasing healthcare-based CPE outbreaks.

Methods : A case was defined as a hospital in-patient testing PCR-positive for CPE (KPC-2 mechanism) from June 2024. Admission and weekly rectal screening was conducted for patients on the same floors as the clinical cases. Screening positivity rates were calculated before and after implementation of control measures. 35 environmental samples were collected. Whole-genome sequencing (WGS) of clinical and environmental samples was performed to understand relatedness. In-hospital movements of cases were plotted to identify common exposure areas.

Results : 33 cases were identified; 31 detected through screening and two in clinical samples. The clinical cases were closely related on WGS, indicating in-hospital transmission. Four environmental samples were CPE-positive; WGS ruled out relatedness for three samples; one sample (from a floor scrubber) was distantly related to the clinical samples. No common exposure areas among cases were identified. Control measures included increased screening, paused elective surgeries, cohorting positive patients, “double” chlorine cleaning, suspending floor scrubbers, staff education, and increased contact precautions. Screening positivity rates dropped from 11.9% to 0.4% after control measure implementation.

Conclusions Despite the hospital's modern design, CPE spread rapidly across multiple areas. Comprehensive control measures contained the outbreak. A definitive link between clinical and environmental isolates was not found but cannot be discounted. With rising global CPE prevalence, our findings highlight the need for strict infection control, even in state-of-the-art hospitals, to prevent future outbreaks.