Antimicrobial Therapy for Legionnaire's Disease: Antibiotic Stewardship Implications.

Legionnaire's disease is a common cause of community-acquired pneumonia (CAP). Although no single clinical feature is diagnostic, if characteristic extrapulmonary findings are present a presumptive clinical syndromic diagnosis is possible. Depending on geographic location, season, and physician awareness, Legionnaire's disease may be included in the differential diagnosis of CAP. Some antibiotics effective against Legionella sp are also effective in treating the typical bacterial causes of CAP. From an antimicrobial stewardship program (ASP) perspective, monotherapy is preferred to double-drug therapy. From an ASP and pharmacoeconomic standpoint, monotherapy with doxycycline or a respiratory quinolone provides optimal cost effective therapy.