Real-world Effectiveness of Cefiderocol Versus Aztreonam/Avibactam

CEFAVI is an observational study that compares the real-world effectiveness of two antibiotics, cefiderocol and aztreonam/avibactam, in patients with infections caused by Gram-negative bacteria that produce metallo-β-lactamases (MBLs). The study will collect and analyze clinical and microbiological information from patients treated with either antibiotic as part of routine clinical care. The aim is to better understand the effectiveness, microbiological response, and safety of these treatments in real-world clinical practice.

Inclusion Criteria: * Adult patients (≥18 years of age). * Microbiologically confirmed infection caused by a metallo-β-lactamase (MBL)-producing Gram-negative bacterium. * Treatment with cefiderocol or aztreonam-avibactam as part of routine clinical care. * Receipt of the study antibiotic for at least 48 hours. Exclusion Criteria: * Patients younger than 18 years. * Absence of microbiological confirmation of an MBL-producing Gram-negative bacterial infection. * Treatment duration of less than 48 hours. * Insufficient clinical or microbiological information to assess the primary outcome.