Treatment duration of community-acquired pneumonia due to Legionella pneumophila: where do we stand?

Introduction While recent guidelines for treatment of community-acquired pneumonia (CAP) recommend short antibiotic duration, evidence regarding Legionella pneumophila pneumonia remains limited. Methods We conducted a narrative review of studies identified via PubMed and Embase, including randomized trials, observational studies and meta-analyses assessing treatment duration and outcomes. Results No randomized trials specifically address legionellosis. Data from CAP consistently support short courses (≤5–7 days), even for atypical pathogens. Observational studies suggest a clinical course similar to that applied for typical CAP, with rapidly attained stability and short intravenous treatment durations. Meta-analyses show no differences in clinical cure, relapse, or mortality between short and long regimens, with fewer adverse events occurring in shorter courses. Conclusion While short-course therapy appears appropriate for legionellosis (3–5 days for non-severe cases, 10–14 days for severe cases and/or immunocompromised patients), prospective studies remain needed.