Epidemiology of community- and nursing home-acquired pneumonia in older adults.

Pneumococcus remains the most important cause of community-acquired pneumonia in older adults. Alcoholism, bronchial asthma, immunosuppression, lung disease, heart disease, institutionalization and increasing age are important risk factors. There is a reduced prevalence of nonrespiratory symptoms in this age group. Advanced age and comorbidity are important prognostic factors. Influenza and pneumococcal vaccination remain the key factors for prevention.