Treatment preferences by infectious diseases clinicians for carbapenem-resistant Enterobacterales infections

New antibiotics effective against carbapenem-resistant Enterobacterales (CRE) provide additional treatment options, but data on clinician decision-making are limited. We sought to understand treatment preferences, factors influencing antibiotic selection for CRE infections and barriers to prescribing newer agents.

We surveyed infectious disease clinicians through the Infectious Diseases Society of America (IDSA) Emerging Infections Network (EIN) about their experience treating CRE infections, availability of resistance mechanism testing, antibiotic choices in four CRE infection scenarios and barriers to using newer antibiotics. We used the 2023 IDSA Guidance on the Treatment of Antimicrobial Resistant Gram-Negative Infections to classify antibiotic selections for the scenario-based questions as preferred approach, alternative option or not in guidance.

Overall, 441 EIN members responded. Among these, 337 (76%) reported treating a CRE infection in the last year. For the clinical scenarios, 851 (63%) of 1356 selections were IDSA-preferred approaches; of these, 653 (77%) were for ceftazidime-avibactam, either alone (n = 456) or in combination with aztreonam (n = 197), more than for other β-lactam/β-lactamase inhibitor combination agents active against CRE. For an uncomplicated urinary tract infection caused by carbapenem-resistant Klebsiella pneumoniae, where no preferred approaches were available, the most common antibiotic selected was oral fosfomycin (169/343 (49%)).

Most clinicians selected antibiotics aligned with the IDSA guidance for serious CRE infections, although the frequent selection of an agent not in the guidance for uncomplicated cystitis suggests that treatment selection is complex and may depend on infection severity, among other factors. The preference for ceftazidime-avibactam among similar agents is notable and may reflect its longer market availability.