What duration of therapy do you use for treatment of Legionella pneumonia in an immunocompetent host without associated empyema or extrapulmonary infection?  

We have little experience of legionellosis, especially in immunocompetent patients. Based on the available information and the published recommendations (these follow), I would generally treat patients for 5-7 days, depending on clinical response.A recent review: Viasus et al., PMID 35505000IDSA/ATS...

Agree, especially regarding azithromycin, given its exceptionally long intracellular half-life. I might extend the duration for a severely ill patient treated with quinolone.