Important infections in elderly persons.

Elderly persons are prone to more frequent or greater morbidity and higher mortality from selected infectious diseases than the average population. Factors that may affect this increased predilection or poorer prognosis include environmental exposure, normal physiological changes of aging, coexistence of chronic diseases and alteration of host defense mechanisms. Infections to which the aged are particularly vulnerable are pneumonia, influenza, tuberculosis, urinary tract infection, Gram-negative bacteremia, intra-abdominal sepsis, soft tissue infection, infective endocarditis, bacterial meningitis, bacterial arthritis and herpes zoster infection.