[Infection in the elderly--what is different?].

Infectious diseases are a common cause of increased morbidity and mortality in elderly patients and present a frequent problem in the geriatrician's daily practice. Infections in the elderly are quite different from infections in a younger population. These differences are due to Age-related alterations in immunology Different epidemiology and bacteriology Increased morbidity and mortality Altered clinical presentation Concommittant disability and comorbidity in many older patients Different approaches to therapy. This article is an attempt to discuss these various aspects of infectious disease in the elderly. The most important infections in the elderly are caused by bacteria. Incidence and bacterial spectrum depends on the site of infection and whether the patient is hospitalized, living in a nursing home or in the community. Pneumonia, UTI and pressure ulcer infections are more frequent in patients living in nursing homes than in community dwelling older people. Infections are a frequent cause of hospitalization in elderly people and hospitalization on the other hand is a risk factor for life-threatening nosocomial infections, caused by invasive diagnostic procedures and frequent use of urinary and venous catheters. Infections in the elderly are often accompanied by serious complications as bacteriemia (pneumonia), frequent recurrence (UTI), perforation and abscess (abdominal infections) and severe disability (pressure ulcer infections). Because of these serious and frequent complications mortality of infections is higher in older patients than in younger people. Elderly patients with infectious disease often present in the same way as younger patients do. Many elderly however present with non-specific clinical symptoms and non-specific functional decline which makes an accurate diagnosis difficult and may lead to a life-threatening delay of diagnosis and therapy. In older patients with unexplained functional decline, physicians must be aware of the possibility of a serious infection. Moreover, the physician can not rely on typical signs of infections as fever. In the elderly the fever response is often blunted even in the presence of bacteremia. Leokocytosis may be absent and elevation of acute phase protein is a more reliable marker of infection than elevation of erythrocyte sedimentation rate. Clinical suspicion of bacterial infection in elderly patient should prompt Careful anamnesis and clinical investigation Hospitalization if necessary Diagnostic procedures without delay including blood cultures Immediate empiric antibiotic therapy taking into account the site of infection, if the infection is community acquired or nosocomial and the most likely bacterial spectrum and local resistance factors. The use of broad spectrum antibiotic substances with a low side effect profile and pharmacokinetic properties which are suitable for elderly patients.