risk factors for persistent enterococcal bacteremia: a multicenter retrospective study

Conditions favoring persistent enterococcal bacteremia (pEB) have not been fully investigated yet. The aim of our study is to analyze risk factors for pEB and its impact on mortality. International two-center retrospective study of all hospitalized adults with enterococcal bacteremia managed with follow-up BCs during the period 2011-2019. Exclusion criteria were: 1) death within 72 hours from index BCs 2) polymicrobial bacteremia. Primary endpoint was P-EB, defined as further isolation of the same species of Enterococcus spp from BCs after at least 72 hours of appropriate antibiotic therapy. Multivariable logistic regression model was performed to assess risk factors for p-EB. The impact of P-EB on 30-day mortality was assessed by Kaplan-Meier survival curve and Cox-regression multivariable model. During the study period, 244 enterococcal bacteremia were diagnosed. P-EB were 13.5% (33/244). At multivariable analysis, factors independently associated with p-EB were hematologic malignancy [OR 4.60,(95% CI 1.32-16.00),p=0.01], infective endocarditis [OR 7.99,(95% CI 2.20-28.9),p=0.002], and use of daptomycin as initial treatment [OR 4.50,(95% CI 1.29-15.61),p=0.018]. Mortality rate was higher in p-EB group (32% vs 18%). Kaplan-Meier survival curve showed that patients with p-EB were less likely to survive at 30 days from index BCs (log-rank p=0.002). Using Cox regression model, independent predictors of 30-day mortality were hematologic malignancy [HR 2.30,(95% CI 1.02-4.11),p=0.043], p-EB [HR 1.93,(95% CI 0.92-4.04,p=0.08] and septic shock [HR 5.92,(95% CI 2.17-16.30),p=0.001]. P-EB were mainly diagnosed in very fragile patients and in those receiving daptomycin as frontline therapy. P-EB may have an impact on mortality.