Community-Acquired Legionella Pneumonia in Elderly Patients: Characteristics and Outcome

OBJECTIVES: To compare the risk factors, clinical and laboratory features, and outcome of community-acquired pneumonia (CAP) caused by Legionella pneumophila in elderly (aged ≥65) and younger patients. DESIGN: Prospective enrollment of subjects with retrospective data analysis. SETTING: A 630-bed tertiary center in Badalona (Barcelona), Spain. PARTICIPANTS: A total of 158 patients diagnosed with CAP caused by L. pneumophila from 1994 to 2004: 104 younger than 65 and 54 aged 65 and older. MEASUREMENTS: Epidemiological, clinical, laboratory, and radiological data and the outcome of the two groups were compared using univariate and multivariate analysis. RESULTS: Underlying diseases, such as chronic pulmonary diseases, diabetes mellitus, neuromuscular diseases, and heart failure; risk of aspiration; and therapy with corticosteroids were significantly more frequent in patients aged 65 and older. Patients younger than 65 were more likely to be male and have toxic habits (cigarette smoking, alcoholism) and human immunodeficiency virus infection than older patients. Fever, nonrespiratory symptoms (diarrhea and headache), and some laboratory abnormalities (hyponatremia (serum sodium concentration