Infection outbreaks caused by carbapenemase-producing Enterobacterales: An epidemiological surveillance study in public hospitals in Chile, 2017–2024

Background Infectious outbreaks caused by carbapenemase-producing Enterobacterales (CPE) in hospitals constitute a global health threat. Objective To characterise CPE infectious outbreaks in public hospitals in Chile during 2017–2024. Methods Retrospective epidemiological surveillance study using national public health data across three periods: baseline pre-pandemic (2017–2019), pandemic (2020−2022), and post-pandemic (2023–2024). Results Seventy-two CPE outbreaks, 945 associated cases and 21 attributable deaths were notified. Median CPE outbreak size in the pre-pandemic period (4 cases) peaked during the pandemic (7 cases) and recovered afterwards post-pandemic (4 cases). Median outbreak duration decreased over time (pre-pandemic period: 75 days; pandemic: 45 days; post-pandemic: 9 days). Klebsiella pneumoniae was the primary cause (83.3% of outbreaks, 92.6% of cases) and KPC the most common carbapenemase detected (54.2% of outbreaks, 53.7% of cases). OXA-48-like and KPC + NDM co-production were observed from 2021 onwards, and IMP was first identified in 2024. Conclusions The size of CPE outbreaks in Chilean public hospitals increased significantly during the pandemic and shrunk back to pre-pandemic values afterwards. CPE outbreak duration decreased sharply from the pandemic onwards. Since 2021, carbapenemases detected in CPE hospital outbreaks have diversified in Chile.