Reported antibiotic treatment practices for severe Legionnaires’ disease in French intensive care units: an exploratory nationwide survey

To describe the usual antimicrobial practices, as reported by a senior physician in each unit, for the treatment of severe Legionnaires’ disease (LD) in French intensive care units (ICUs), focusing on antimicrobial selection, the choice between single and dual therapy, and treatment duration. A cross-sectional declarative survey was conducted between January and March 2024 among French ICUs. Overall, 51 out of 290 ICUs (17.6%) participated. Dual therapy was reported as the usual strategy by 68.6% (35/51) of respondents, with all of them using a combination of fluoroquinolones and macrolides. Among these, 71.4% reported a secondary switch to single therapy. Total treatment duration most commonly ranged between 14 and 21 days (86.3%). Single therapy was reported by 31.4% (16/51) of ICUs, with fluoroquinolones as the reported first-line agent in 68.8% of these cases. De-escalation and intravenous-to-oral switch practices varied widely. Despite recent health authority warnings limiting their use, fluoroquinolones remain a cornerstone of severe LD management in ICUs. These findings highlight significant practice heterogeneity and underscore the need for randomized controlled trial to optimize antimicrobial strategies. Not applicable.