P21. Clinical and epidemiological characteristics of Enterococcus faecium bloodstream infections: a retrospective study in a large university hospital in Italy

Enterococcus faecium bloodstream infections (E-BSI) rank second among the Gram-positive BSI in Europe carrying significant burden of morbidity and mortality, with progressive increase of vancomycin-resistant isolates (VRE) in Italy.

Five-years (2019–2023) retrospective observational study including all patients admitted in Perugia Hospital. Primary outcome was 30-days mortality, the secondary being differences between VRE and VSE E-BSI.

We identified 216 episodes of BSI in 211 patients (55.9% male, median age 74). A predisposing condition was found in 96.2% of the patients, 82.5% having at least 2; the most represented ones were oncohematological malignancy (56.7%), cardiovascular disease (53.2%) and bilio-enteric disease (46.3%). Median Charlson score was 6.5, 48.3% of the patients had been hospitalized in the previous 90 days and 74.8% of the episodes were healthcare associated, occurring a median of 11 days after admission; 35.1% of patients had surgery in the previous 90 days. Urinary catheter was present in 62.1%, a central venous catheter (CVC) in 55.5%. 93.4% of patients had received antibiotics in the previous 90 days.

Primary E-BSI accounted for 35.5% of cases, 34.6% were CVC-related while14.2% originated from biliary tract. Polymicrobial BSI were 28.4%. VRE represented 51.9% of cases. Clinical presentation was sepsis in 37.9%, septic shock in 24.2% (being more frequent in VRE cases than VSE ones, 29.6% versus 18.4%, P 0,057), endocarditis in 4.3%. 30-days in-hospital overall mortality was 35.1%, while E-BSI attributable mortality was 9.5%, without significant differences between VRE and VSE-BSI. Multivariate analysis showed that septic shock (P 0.0039), higher SOFA score (P 0.0048) and no removal of device (P 0.037) were significantly associated with mortality. Temporal trends show increase in the overall incidence until 2021 with a subsequent drop, while VRE cases exceed VSE ones from 2021. Highest incidence was observed in Intensive care area (1.38 cases/1000 bed-days) with a steady increase, while incidence in other areas remained stable.

Our study shows E-BSI represents a significant and growing healthcare-associated infection. VRE cases are increasing and seem to be more aggressive although we didn’t find a difference in mortality between susceptible and resistant strains.