Objective: We evaluated the epidemiology of carbapenemase-producing bacteria (CPB) in Switzerland by comparing risk factors between patients colonized with CPB and patients colonized with extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE).
Methods: This retrospective cohort study was conducted at the University Hospital Basel in Switzerland. Hospitalized patients with CPB in any sample between January 2008 and July 2019 were included. The ESBL-PE group consisted of hospitalized patients with detection of ESBL-PE from any sample between January 2016 and December 2018. Comparisons of risk factors for acquisition of CPB and ESBL-PE were performed by logistic regression.
Results: Inclusion criteria were met for 50 patients in the CPB group and 572 in the ESBL-PE group. In the CPB group, 62% had a travel history and 60% had been hospitalized abroad. When comparing the CPB group to the ESBL-PE group, hospitalization abroad (odds ratio [OR], 25.33; 95% confidence interval [CI], 11.07-57.98) and prior antibiotic therapy (OR, 4.76; 95% CI, 2.15-10.55) remained independently associated with CPB colonization. Hospitalization abroad (P < .001) and prior antibiotic therapy (P < .001) predicted CPB in the comparison of CPB with ESBL Escherichia coli, whereas hospitalization abroad was associated with CPB in comparison to ESBL Klebsiella pneumoniae.
Conclusions: Although CPB still seem to be mainly imported from areas of higher endemicity, local acquisition of CPB is emerging, especially in patients with close and/or frequent contact with healthcare services. This trend resembles the epidemiology of ESBL K. pneumoniae, supporting mainly healthcare-associated transmission. Frequent evaluation of CPB epidemiology is required to improve detection of patients at risk of CPB carriage.