Treatment of Legionellosis Including a Single Intravenous Dose of 1.5 g Azithromycin: 18-year Experience at a Tertiary Care Hospital

Abstract Objectives Due to recent safety concerns regarding fluoroquinolones and the potential medical and economic benefits, we investigated the efficacy of a single intravenous dose of azithromycin 1.5 g for treatment of pulmonary legionellosis. Methods Using a nationwide legionellosis registry for preselection, 74 patients admitted form 2000-2018 at a tertiary care hospital due to pneumonia caused by Legionella pneumophila were retrospectively included in this study. Results Conventional regimes consisting of fluoroquinolones (n=20), macrolides (n=30) or combinations of both (n=24) and a single intravenous dose of azithromycin (n=12) have been demonstrated to be equally effective. Single-dose azithromycin treatment was well tolerated, resulted in a shorter hospital stay (p=0.0464) and a shorter antibiotic treatment duration (p=0.0004) allowing earlier discharge. Conclusion A single intravenous dose of azithromycin might be a valuable treatment alternative for patients with legionellosis.