Infections in the elderly.

Why should every clinician know something about the management of infections in the elderly? First, consider the numbers, the so-called "geriatric demographic imperative." In 1900, about 15 million people were aged 65 years or older (< 1% of the global population). In 1992, 342 million people were in this age group (6.2% of the population), and by the year 2050, this number is projected to expand to 2.5 billion (about 20% ofthe world's population). Second, elderly individuals are at increased risk of having or dying from virtually every serious infectious disease, such as pneumonia, meningitis, endocarditis, cellulitis, and infections of the urinary and gastrointestinal tracts. Third, many of these infections are preventable and, if diagnosed and treated promptly, are not necessarily associated with any greater mortality than those in young adults. Finally, since most clinicians have family members, if not patients, who are elderly, it is important to be alert to the , 'unusual" presentation of life-threatening infections in the elderly. Before discussing the special considerations of infections in the elderly, it should be pointed out that a clinically satisfactory definition of the term elderly is lacking. The arbitrary use of chronological age (i.e., older than 60, 65, or 70 years of age) does not account for substantial variability in the rate of physiological aging. Indeed, only a small proportion of the population who are older than 60 years of age is "geriatric" (i.e., has chronic medical problems associated with growing old). Some of the literature on infections in the elderly may highlight features that are common in true geriatric patients and may not be representative of all elderly individuals, most of