Epidemiology and etiology of community-acquired pneumonia.

The seriousness of community-acquired pneumonia (CAP), despite being a reasonably common and potentially lethal disease, often is under estimated by physicians and patients alike. CAP results in more than 10 million visits to physicians, 64 million days of restricted activity, and 600,000 hospitalizations. This article discusses the epidemiology and bacterial causes of CAP in immunocompetent adults and the severe acute respiratory syndrome coronavirus.