Infections in older patients: a systematic clinical approach.

The increased risk of infection among older patients can be divided into three clinical categories: infections increased in incidence, infections showing higher case fatality rates, and infections that are clinically worse, primarily because of late recognition. Among infections that are increased in incidence, the most important by far are tuberculosis and pneumococcal pneumonia. Infections that show higher fatality rates include influenza and--again--pneumococcal pneumonia. Intra-abdominal infections (eg, cholecystitis and appendicitis) are often clinically worse in older patients due to late recognition and delay in surgical intervention.