Persistent culture-positive Legionella infection in an immunocompromised host.

Legionella pneumophila is an important cause of community-acquired and nosocomial pneumonia. We describe an immunocompromised patient with severe pneumonia from whom Legionella species were isolated from sputum samples by culture for 30 days, despite administration of treatment with appropriate antimicrobial agents. However, clear improvement in the patient's respiratory condition was evident, and he subsequently recovered completely.