Thomas T. Yoshikawa

Herpes Zoster in Older Adults

Herpes zoster (HZ) strikes millions of older adults annually worldwide and disables a substantial number of them via postherpetic neuralgia (PHN). Key age-related clinical, epidemiological, and treatment features of zoster and PHN are reviewed. HZ is caused by renewed replication and spread of varicella-zoster virus (VZV) in sensory ganglia and afferent peripheral nerves in the setting of age-related, disease-related, and drug-related decline in cellular immunity to VZV. VZV-induced neuronal destruction and inflammation causes the principal problems of pain, interference with activities of daily living, and reduced quality of life in elderly patients. Recently, attempts to reduce or eliminate HZ pain have been bolstered by the findings of clinical trials that antiviral agents and corticosteroids are effective treatment for HZ and that tricyclic antidepressants, topical lidocaine, gabapentin, and opiates are effective treatment for PHN. Although these advances have helped, PHN remains a difficult condition to prevent and treat in many elderly patients.

Epidemiology and Unique Aspects of Aging and Infectious Diseases

The elderly population will grow rapidly over the next 25 years. The majority of patients with serious or life-threatening infections will be old. It is imperative that primary care physicians and infectious diseases specialists become aware of and knowledgeable about the special and unique aspects of infections in the geriatric population.

Clinical practice guideline for the evaluation of fever and infection in older adult residents of long-term care facilities: 2008 update by the Infectious Diseases Society of America.

Residents of long-term care facilities (LTCFs) are at great risk for infection. Most residents are older and have multiple comorbidities that complicate recognition of infection; for example, typically defined fever is absent in more than one-half of LTCF residents with serious infection. Furthermore, LTCFs often do not have the on-site equipment or personnel to evaluate suspected infection in the fashion typically performed in acute care hospitals. In recognition of the differences between LTCFs and hospitals with regard to hosts and resources present, the Infectious Diseases Society of America first provided guidelines for evaluation of fever and infection in LTCF residents in 2000. The guideline presented here represents the second edition, updated by data generated over the intervening 8 years. It focuses on the typical elderly person institutionalized with multiple chronic comorbidities and functional disabilities (e.g., a nursing home resident). Specific topic reviews and recommendations are provided with regard to what resources are typically available to evaluate suspected infection, what symptoms and signs suggest infection in a resident of an LTCF, who should initially evaluate the resident with suspected infection, what clinical evaluation should be performed, how LTCF staff can effectively communicate about possible infection with clinicians, and what laboratory tests should be ordered. Finally, a general outline of how a suspected outbreak of a specific infectious disease should be investigated in an LTCF is provided.

Practice guideline for evaluation of fever and infection in long-term care facilities

The elderly population (i.e., persons aged > or = 65 years) in the United States is rapidly expanding and will nearly double in number over the next 30 years. It is estimated that >40% of persons aged > or = 65 years will require care in a long-term care facility (LTCF), such as a skilled nursing facility (SNF), at some point during their lifetime. For the most part, residents of LTCFs are very old and have age-related immunologic changes, chronic cognitive and/or physical impairments, and diseases that alter host resistance; therefore, they are highly susceptible to infections and their complications. The diagnosis of infections in residents of LTCFs is often difficult because LTCFs differ from acute-care facilities in their goals of care, staffing ratios, types of primary care providers, availability of laboratory tests, and criteria for infections. Consequently, guidelines and standards of practice used for diagnosis of infections in patients in acute-care facilities may not be applicable nor appropriate for residents in LTCFs. Moreover, the clinical manifestations of diseases and infections are often subtle, atypical, or nonexistent in the very old. Fever may be low or absent in LTCF residents with infection. The initial evaluation of an LTCF resident suspected of an infection may not be done by a physician. Although nurses commonly perform initial assessments for infection in residents of LTCFs, further studies are needed to determine the appropriateness and validity of this practice. Provided there are no directives (advance or current by resident or caregiver) limiting diagnostic or therapeutic interventions, all residents of LTCFs with suspected symptomatic infection should have appropriate diagnostic laboratory studies done promptly, and the findings should be discussed with the primary care clinician (see Recommendations). The most common infections among LTCF residents are urinary tract infections, respiratory infections, skin or soft tissue infections, and gastroenteritis. Decisions concerning possible transfer of an LTCF resident to an acute-care facility are best expressed through an advance directive or, when not available, through transfer policies developed by the LTCF. In general, LTCF residents have been transferred to an acute-care facility when any of the following conditions exist: (1) the resident is clinically unstable and the resident or family goals indicate aggressive interventions should be initiated, (2) critical diagnostic tests are not available in the LTCF, (3) necessary therapy or the mode of administration of therapy (frequency or monitoring) are beyond the capacity of the LTCF, (4) comfort measures cannot be assured in the LTCF, and (5) specific infection-control measures are not available in the LTCF.

Antimicrobial Resistance and Aging: Beginning of the End of the Antibiotic Era?

Throughout the history of mankind, infectious diseases have remained a major cause of death and disability. Although industrialized nations, such as the United States, have experienced significant reductions in infection‐related mortality and morbidity since the beginning of the “antibiotic era,” death and complications from infectious diseases remain a serious problem for older persons. Pneumonia is the major infection‐related cause of death in older persons, and urinary tract infection is the most common bacterial infection seen in geriatric patients. Other serious and common infections in older people include intra‐abdominal sepsis, bacterial meningitis, infective endocarditis, infected pressure ulcers, septic arthritis, tuberculosis, and herpes zoster. As a consequence, frequent prescribing of antibiotics for older patients is common practice. The large volume of antibiotics prescribed has contributed to the emergence of highly resistant pathogens among geriatric patients, including methicillin‐resistant Staphylococcus aureus, penicillin‐resistant Streptococcus pneumoniae, vancomycin‐resistant enterococci, and multiple‐drug‐resistant gram‐negative bacilli. Unless preventive strategies coupled with newer drug development are established soon, eventually clinicians will be encountering infections caused by highly resistant pathogens for which no effective antibiotics will be available. Clinicians could then be experiencing the same frustrations of not being able to treat infections effectively as were seen in the “pre‐antibiotic era.”

INFECTIONS IN DIABETES

Diabetics are predisposed to infections because of various immune deficiencies, including neutrophil and monocyte dysfunction. Some of these immune deficiencies are improved by tight glucose control. This article is a review of the immune deficiencies seen in diabetes and an overview of selected infections that are commonly or predominantly seen in diabetics.

Fever Response in Elderly Nursing Home Residents: Are the Older Truly Colder?

Objective To test the hypothesis that many nursing home residents with an apparently blunted fever response (maximum temperature <101°F) may actually have a significant change in temperature (ΔT ≥ 2.4°F) which is not recognized because of a low baseline temperature.

Fungal Infections in Older Adults

Invasive fungal infections have become an increasing problem in older adults. Infections with opportunistic fungi have increased because older patients are more likely to be considered for transplantation, receive aggressive regimens of chemotherapy for cancer, and take immunosuppressive drugs for nonmalignant diseases. In addition, healthy older adults are now more likely to travel extensively and to indulge in outdoor activities, which put them at risk for exposure to endemic mycoses. Although many of the clinical manifestations of fungal infections in older and younger adults are similar, there are aspects of histoplasmosis, aspergillosis, and cryptococcosis that are unique to older patients. Treatment of older adults with amphotericin B is difficult because of the intrinsic nephrotoxicity of the drug. Although they are less toxic, azoles must be used carefully for treatment of older adults, who are more likely to experience serious drug-drug interactions than are younger persons.

Perspective: Aging and Infectious Diseases: Past, Present, and Future

As we enter into the 21st century, infectious disease specialists will be managing a greater number and proportion of patients with infections who are > or = 65 years old. Much has been learned about aging, host resistance, and infections over the past 15 years. However, if we are to meet the challenge of the complex issues of geriatric infectious diseases, infectious disease clinicians, teachers, and researchers must assume a more proactive role in clinical care, training, education, and research on problems and issues confronting the aging population.

A New Paradigm for Clinical Investigation of Infectious Syndromes in Older Adults: Assessment of Functional Status as a Risk Factor and Outcome Measure

Adults aged >or=65 years comprise the fastest-growing segment of the United States population, and older adults experience greater morbidity and mortality due to infection than do young adults. Although age is well established as a risk factor for infection, most clinical investigations of infectious diseases in older adults focus on microbiology and on crude end points of clinical success, such as cure rates or death; however, they often fail to assess functional status, which is a critical variable in geriatric care. Functional status can be evaluated either as a risk factor for infectious disease or as an outcome of interest after specific interventions using well-validated instruments. This article outlines the currently available data that suggest an association between infection, immunity, and impaired functional status in elderly individuals, summarizes the instruments commonly used to determine specific aspects of functional status, and provides recommendations for a new paradigm in which clinical trials that involve older adults include assessment of functional status.