Proactive antimicrobial stewardship with real-time microbiological alerts improves management of bloodstream infections

Introduction This study aims to assess the impact of proactive Infectious Disease Specialist (IDS) interventions, in addition to standard antimicrobial stewardship (AMS) practices, triggered by real-time microbiological alerts, on improving the appropriateness and timeliness of antimicrobial prescriptions in hospitalized patients with bloodstream infections (BSIs). Methods We conducted a prospective, single-center, pre-post interventional study at the University Hospital of Modena, Italy. Adult inpatients with monomicrobial BSIs between June 2022 and March 2023 were included. During the intervention phase (November 2022–March 2023), real-time microbiological alerts were automatically delivered to IDS consultants, who proactively reviewed therapy. Primary outcomes included the time to effective therapy (TTE) and the time to appropriate therapy (TTA). Secondary outcomes encompassed the duration of antimicrobial therapy, 14 and 30-day mortality from BSI, and hospital length of stay. Results A total of 446 BSI episodes were analyzed (211 pre-intervention, 235 post-intervention). Post-intervention, the rate of appropriate therapy significantly increased (97.4% versus 76.2%, P < 0.001), and TTE was significantly shorter (0.63 versus 0.87 days, P = 0.022). No statistically significant reduction in TTA was observed (1.97 versus 2.37 days, P = 0.081). Early IDS intervention (<48 h) was associated with the shortest TTE and TTA. No significant differences were observed in mortality or hospital stay. Kaplan–Meier analysis showed a higher probability of receiving effective and appropriate therapy earlier in the post-intervention phase (log-rank test P = 0.014; 0.072, respectively). Subgroup analysis showed TTE improvements across MDR pathogens. Conclusions A proactive intervention of IDS, based on automatic microbiological alert, in addition to routine AMS activities, is significantly associated with improved prescription appropriateness, reducing TTE.