Travel-associated carbapenemase-producing Enterobacterales: Epidemiology and risk factors in a Finnish cohort

Background: Carbapenemase-producing Enterobacterales (CPE) are increasing worldwide, with strains associated with difficult-to-treat infections. We previously reported that international travel is a major source of CPE acquisition in the Helsinki region, Finland. To clarify the extent of importation, we investigated the epidemiology and associated risk factors of foreign-acquired CPEs. Methods: We revisited two earlier cohorts. Cohort A (n = 187 after a one-year extension) comprised patients from 2010 through 2024 presumed to have acquired CPE abroad; CPE types were categorized by travel region. Cohort B included 3029 patients screened for CPE from 2010 through 2019 within 12 months after hospitalization abroad. Multivariable analysis identified factors that predispose to colonization. Results: Among patients hospitalized abroad (Cohort B), CPE rates were particularly high for South Asia (14.6 %) and North Africa (13.7 %). Across the 24 individual countries with data, the highest CPE colonization risks were observed for Egypt (20.8 %) and India (16.4 %). In addition to destination, independent risk factors included antibiotic use, travel type, short interval between discharge from a foreign hospital and screening (within one week or one month) and male sex. For South/Southeast Asia and sub-Saharan Africa, over 70 % of CPE carriers (Cohort A) had metallo-β-lactamase-producing Enterobacterales, predominantly NDM, whereas OXA-48–like enzymes predominated in North Africa and the Middle East. Conclusions: Hospitalization in high-prevalence countries and antibiotic use emerged as key risk factors for CPE acquisition. Regional variation was evident: OXA-48–like enzymes dominated among CPEs linked to the Middle East and North Africa, whereas NDM was prevalent elsewhere in Eurasia and Africa.