The evolving epidemiology of Carbapenemase-producing Enterobacterales in Canadian acute care facilities, 2010-2023

Carbapenemase-producing Enterobacterales (CPE) are associated with substantial morbidity and mortality with limited treatment options and have an ability to spread rapidly in healthcare settings. We analyzed surveillance data from the Canadian Nosocomial Infection Surveillance Program to describe trends and the epidemiology of CPE from 2010 to 2023.

Participating acute-care hospitals submitted eligible isolates to the National Microbiology Laboratory for detection of carbapenemase genes. Trained infection control professionals applied standardized definitions to collect epidemiological data by chart review from 30-97 hospitals from 2010 to 2023.

The national incidence of CPE infection (0.03 to 0.14 per 10,000 patient days; R² = 0.76) and colonization (0.02 to 0.78 per 10,000 patient days; R² = 0.83) increased exponentially from 2010 to 2023. We identified rapidly rising rates of healthcare-associated (HA) CPE infections from 2019 to 2023 (0.05 to 0.09 per 10,000 patient-days, p = 0.04), attributed to select hospitals (7/97) which accounted for half (53%) of all HA-CPE infections in 2023. Similarly, we identified that 2023 HA-CPE colonization rates were highest in medium (201-499 beds) and large (≥500 beds) hospitals in the Central region. Most patients did not report international travel (66%) nor receipt of medical care abroad (74%). Travel and receipt of medical care were less commonly reported among bla_KPC associated cases (7.1% and 5.3% respectively) compared to bla_NDM (55% and 45% respectively) and bla_OXA-48 (57% and 39%) associated cases. Furthermore, bla_KPC was the predominant carbapenemase among all HA-CPE isolates (62%, 950/1,534).

Surveillance data from a national network of Canadian acute care hospitals indicates that while the incidence of CPE in Canada remains low, it is accelerating at an exponential rate. Our findings suggest that nosocomial transmission is driving the recent increase in CPE incidence in Canada. Improved infection control measures and antimicrobial stewardship as well as access to newer antimicrobials are all urgently needed.