Abstract

BACKGROUND. Carbapenem-resistant Enterobacterales (CRE) pose a significant global health threat. Among them, carbapenemase-producing Enterobacterales (CP-CRE) are particularly worrisome. Official data showed most CRE in Chile were non-carbapenemase producing CRE (non-CP-CRE). Reports from different regions suggest there was an increase in CP-CRE after the Covid-19 pandemic. Using a surveillance network from 11 Chilean hospitals, we aimed to describe carbapenemase production before-after the pandemic in invasive CRE isolates collected from 2018-2023, and to characterize patients with infections due to CP- and non-CP-CRE. METHODS. We prospectively collected isolates and clinical metadata from patients with culture-confirmed CRE invasive infections (i.e., bloodstream, sterile fluids/tissue) from June/2018-September/2023. CRE was defined as resistance to >1 carbapenem. All isolates were studied for carbapenemase genes (blaKPC, blaNDM, and blaVIM) by PCR. Clinical characteristics and outcomes of infected patients were compared using T-test, Wilcoxon Rank-Sum, or Chi2/Fisher's exact test, as appropriate. RESULTS. A total of 1,514 CRE isolates from 1,130 patients were recovered in the study period. The most frequent species were Klebsiella pneumoniae (75%) and Enterobacter cloacae (13%). The prevalence of CP-CRE increased from 10% in 2018-2019 to 47% in 2023 (Figure 1). Importantly, the highest increase was observed in metalloenzymes, with blaNDM accounting for 51% of CP-CRE in 2023. Out of 334 patients analyzed with invasive CRE infections, 100 (30%) had CP-CRE and 234 (70%) had a non-CP-CRE. Subjects with non-CP-CRE infections were significantly older and had a higher Charlson score (Table 1). Total ICU stay was significantly higher in the CP-CRE group (34 vs. 21 days, p=0.029). Overall, in-hospital and 14-day mortality did not differ significantly between both groups (Table 1). CONCLUSION. We observed a steep increase in the prevalence of CP-CRE infections after the Covid-19 pandemic with metalloenzymes (blaNDM) accounting for a majority of the carbapenemases observed. Our preliminary analyses of the clinical metadata suggest mortality of patients infected with CP- and non-CP-CRE are similar.