The microbiota and microbiome in aging: potential implications in health and age-related diseases.

Advances in bacterial deoxyribonucleic acid sequencing allow for characterization of the human commensal bacterial community (microbiota) and its corresponding genome (microbiome). Surveys of healthy adults reveal that a signature composite of bacteria characterizes each unique body habitat (e.g., gut, skin, oral cavity, vagina). A myriad of clinical changes, including a basal proinflammatory state (inflamm-aging), that directly interface with the microbiota of older adults and enhance susceptibility to disease accompany aging. Studies in older adults demonstrate that the gut microbiota correlates with diet, location of residence (e.g., community dwelling, long-term care settings), and basal level of inflammation. Links exist between the microbiota and a variety of clinical problems plaguing older adults, including physical frailty, Clostridium difficile colitis, vulvovaginal atrophy, colorectal carcinoma, and atherosclerotic disease. Manipulation of the microbiota and microbiome of older adults holds promise as an innovative strategy to influence the development of comorbidities associated with aging.

A cluster-randomized controlled trial of a multicomponent intervention protocol for pneumonia prevention among nursing home elders.

BACKGROUND: Pneumonia remains an important public health problem among elderly nursing home residents. This clinical trial sought to determine if a multicomponent intervention protocol, including manual tooth/gum brushing plus 0.12% chlorhexidine oral rinse, twice per day, plus upright positioning during feeding, could reduce the incidence of radiographically documented pneumonia among nursing home residents, compared with usual care. METHODS: This cluster-randomized clinical trial was conducted in 36 nursing homes in Connecticut. Eligible residents >65 years with at least 1 of 2 modifiable risk factors for pneumonia (ie, impaired oral hygiene, swallowing difficulty) were enrolled. Nursing homes were randomized to the multicomponent intervention protocol or usual care. Participants were followed for up to 2.5 years for development of the primary outcome, a radiographically documented pneumonia, and secondary outcome, a lower respiratory tract infection (LRTI) without radiographic documentation. RESULTS: A total of 834 participants were enrolled: 434 to intervention and 400 to usual care. The trial was terminated for futility. The number of participants in the intervention vs control arms with first pneumonia was 119 (27.4%) vs 94 (23.5%), respectively, and with first LRTI, 125 (28.8%) vs 100 (25.0%), respectively. In a multivariable Cox regression model, the hazard ratio in the intervention vs control arms, respectively, was 1.12 (95% confidence interval [CI], .84-1.50; P = .44) for first pneumonia and 1.07 (95% CI, .79-1.46, P = .65) for first LRTI. CONCLUSIONS: The multicomponent intervention protocol did not significantly reduce the incidence of first radiographically confirmed pneumonia or LRTI compared with usual care in nursing home residents. CLINICAL TRIALS REGISTRATION: NCT00975780.

Outcomes among older adult liver transplantation recipients in the model of end stage liver disease (MELD) era.

BACKGROUND: Since 2002, the Model of End Stage Liver Disease (MELD) score has been the basis of the liver transplant (LT) allocation system. Among older adult LT recipients, short-term outcomes in the MELD era were comparable to the pre-MELD era, but long-term outcomes remain unclear. MATERIAL AND METHODS: This is a retrospective cohort study using the UNOS data on patients age ≥ 50 years who underwent primary LT from February 27, 2002 until October 31, 2011. RESULTS: A total of 35,686 recipients met inclusion criteria. The cohort was divided into 5-year interval age groups. Five-year over-all survival rates for ages 50-54, 55-59, 60-64, 65-69, and 70+ were 72.2%, 71.6%, 69.5%, 65.0%, and 57.5%, respectively. Five-year graft survival rates after adjusting for death as competing risk for ages 50-54, 55-59,60-64, 65-69 and 70+ were 85.8%, 87.3%, 89.6%, 89.1% and 88.9%, respectively. By Cox proportional hazard modeling, age ≥ 60, increasing MELD, donor age ≥ 60, hepatitis C, hepatocellular carcinoma (HCC), dialysis and impaired pre-transplant functional status (FS) were associated with increased 5-year mortality. Using Fine and Gray sub-proportional hazard modeling adjusted for death as competing risk, 5-year graft failure was associated with donor age ≥ 60, increasing MELD, hepatitis C, HCC, and impaired pre-transplant FS. CONCLUSIONS: Among older LT recipients in the MELD era, long-term graft survival after adjusting for death as competing risk was improved with increasing age, while over-all survival was worse. Donor age, hepatitis C, and pre-transplant FS represent potentially modifiable risk factors that could influence long-term graft and patient survival.

The ability of virulence factor expression by Pseudomonas aeruginosa to predict clinical disease in hospitalized patients.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic pathogen that frequently causes hospital acquired colonization and infection. Accurate identification of host and bacterial factors associated with infection could aid treatment decisions for patients with P. aeruginosa cultured from clinical sites. METHODS: We identified a prospective cohort of 248 hospitalized patients with positive P. aeruginosa cultures. Clinical data were analyzed to determine whether an individual met predefined criteria for infection versus colonization. P. aeruginosa isolates were tested for the expression of multiple phenotypes previously associated with virulence in animal models and humans. Logistic regression models were constructed to determine the degree of association between host and bacterial factors with P. aeruginosa infection of the bloodstream, lung, soft tissue and urinary tract. RESULTS: One host factor (i.e. diabetes mellitus), and one bacterial factor, a Type 3 secretion system positive phenotype, were significantly associated with P. aeruginosa infection in our cohort. Subgroup analysis of patients with P. aeruginosa isolated from the urinary tract revealed that the presence of a urinary tract catheter or stent was an additional factor for P. aeruginosa infection. CONCLUSIONS: Among hospitalized patients with culture-documented P. aeruginosa, infection is more likely to be present in those with diabetes mellitus and those harboring a Type 3 secretion positive bacterial strain.

Efficacy and effectiveness as aspects of cluster randomized trials with nursing home residents: methodological insights from a pneumonia prevention trial.

This report discusses how methodological aspects of study efficacy and effectiveness combine in cluster randomized trials in nursing homes. Discussion focuses on the relationships between these study aspects in the Pneumonia Reduction in Institutionalized Disabled Elders (PRIDE) trial, an ongoing cluster randomized clinical trial of pneumonia prevention among nursing home residents launched in October 2009 in Greater New Haven, Connecticut. This clinical trial has enrolled long-term care nursing home residents, over 65years in age, who have either inadequate oral care or swallowing difficulty, previously identified risk factors for pneumonia. It has used a multicomponent intervention consisting of manual tooth/gum brushing, 0.12% chlorhexidine oral rinse administered twice daily by nurses, and upright feeding positioning at meals to reduce rates of radiographically documented pneumonia. Cluster randomization is attractive for nursing home intervention studies because physical proximity and administrative arrangements make it difficult to deliver different interventions to residents of the same nursing home. Implementing an intervention in an entire home requires integration into the daily life of residents and into the administrative procedures of the nursing home. This characteristic of nursing home cluster randomized trials makes them approximate "real-world" research contexts, but implementation can be challenging. The PRIDE trial of pneumonia prevention utilized specific methodological choices that include both efficacy and effectiveness elements. Cluster randomized trials in nursing homes having elements of both efficacy and effectiveness (i.e., hybrid designs) can address some of the methodological challenges of conducting clinical research in nursing homes; they have distinctive advantages and some limitations.

Infectious diseases in the nursing home setting: challenges and opportunities for clinical investigation.

The global population is aging. With the high prevalence of dementia and functional decline in older Americans, many aging adults with disabilities reside in nursing homes in their final stage of life. Immunosenescence, multiple comorbid diseases, and grouped quarter living all coalesce in nursing home residents to increase the risk for infectious disease. The unique issues involved with diagnosis, prognosis, and management of infectious diseases in nursing home residents make research based in the nursing home setting both necessary and exciting for the physician investigator. This review discusses the opportunities and challenges involved with research of the evolving public health problem of infections among nursing home residents.

Pandemic influenza H1N1 2009, innate immunity, and the impact of immunosenescence on influenza vaccine.

Seasonal and pandemic strains of influenza have widespread implications for the global economy and global health. This has been highlighted recently as the epidemiologic characteristics for hospitalization and mortality for pandemic influenza H1N1 2009 are now emerging. While treatment with neuraminidase inhibitors are effective for seasonal and pandemic influenza, prevention of morbidity and mortality through effective vaccines requires a rigorous process of research and development. Vulnerable populations such as older adults (i.e., > age 65 years) suffer the greatest impact from seasonal influenza yet do not have a consistent seroprotective response to seasonal influenza vaccines due to a combination of factors. This short narrative review will highlight the emerging epidemiologic characteristics of pandemic H1N1 2009 and focus on immunosenescence, innate immune system responses to influenza virus infection and vaccination, and influenza vaccine responsiveness as it relates to seasonal and H1N1 pandemic influenza vaccines.

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.

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.

Nursing home practitioner survey of diagnostic criteria for urinary tract infections.

OBJECTIVES: To identify clinical and laboratory criteria used by nursing home practitioners for diagnosis and treatment of urinary tract infections (UTIs) in nursing home residents. To determine practitioner knowledge of the most commonly used consensus criteria (i.e., McGeer criteria) for UTIs. DESIGN: Self-administered survey. SETTING: Three New Haven-area nursing homes. PARTICIPANTS: Physicians (n=25), physician assistants (PAs, n=3), directors/assistant directors of nursing (n=8), charge nurses (n=37), and infection control practitioners (n=3). MEASUREMENTS: Open- and closed-ended questions. RESULTS: Nineteen physicians, three PAs, and 41 nurses completed 63 of 76 (83%) surveys. The five most commonly reported triggers for suspecting UTI in noncatheterized residents were change in mental status (57/63, 90%), fever (48/63, 76%), change in voiding pattern (44/63, 70%), dysuria (41/63, 65%), and change in character of urine (37/63, 59%). Asked to identify their first diagnostic step in the evaluation of UTIs, 48% (30/63) said urinary dipstick analysis, and 40% (25/63) said urinalysis and urine culture. Fourteen of 22 (64%) physicians and PAs versus 40 of 40 (100%) nurses were aware of the McGeer criteria for noncatheterized patients (P<.001); 12 of 22 (55%) physicians and PAs versus 38 of 39 (97%) nurses used them in clinical practice (P<.001). CONCLUSION: Although surveillance and treatment consensus criteria have been developed, there are no universally accepted diagnostic criteria. This survey demonstrated a distinction between surveillance criteria and criteria practitioners used in clinical practice. Prospective data are needed to develop evidence-based clinical and laboratory criteria of UTIs in nursing home residents that can be used to identify prospectively tested treatment and prevention strategies.

Prognostic scoring systems for infectious diseases: their applicability to the care of older adults.

Physicians often make clinical predictions about individual patients. For many infectious diseases, published prognostic scoring systems (PSSs) can help predict relevant outcomes. Validated PSSs exist for the general adult population for diseases such as pneumonia, endocarditis, meningitis, and bloodstream infection. Although these PSSs have been rigorously derived and validated, they have limited value in the care of older adults, because most studies have involved a heterogeneous adult population with mortality as the primary end point. In the United States, the number of patients who are > or =65 years old is growing, and their health care costs are increasing. Assessment of clinical outcomes other than merely survival (i.e., physical functional ability, cognitive ability, need for nursing home care, and overall quality of life) is required for this population. Some pioneering work has been done to develop PSSs that specifically address the health care needs of older adults. This review will describe existing PSSs and explore areas of further investigation.

Impact of valve surgery on 6-month mortality in adults with complicated, left-sided native valve endocarditis: a propensity analysis.

CONTEXT: Complicated, left-sided native valve endocarditis causes significant morbidity and mortality in adults. The presumed benefits of valve surgery remain unproven due to lack of randomized controlled trials. OBJECTIVE: To determine whether valve surgery is associated with reduced mortality in adults with complicated, left-sided native valve endocarditis. DESIGN AND SETTING: Retrospective, observational cohort study conducted from January 1990 to January 2000 at 7 Connecticut hospitals. Propensity analyses were used to control for bias in treatment assignment and prognostic imbalances. PATIENTS: Of the 513 adults with complicated, left-sided native valve endocarditis, 230 (45%) underwent valve surgery and 283 (55%) received medical therapy alone. MAIN OUTCOME MEASURE: All-cause mortality at 6 months after baseline. RESULTS: In the 6-month period after baseline, 131 patients (26%) died. In unadjusted analyses, valve surgery was associated with reduced mortality (16% vs 33%; hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.29-0.63; P<.001). After adjustment for baseline variables associated with mortality (including hospital site, comorbidity, congestive heart failure, microbial etiology, immunocompromised state, abnormal mental status, and refractory infection), valve surgery remained associated with reduced mortality (adjusted HR, 0.35; 95% CI, 0.23-0.54; P<.02). In further analyses of 218 patients matched by propensity scores, valve surgery remained associated with reduced mortality (15% vs 28%; HR, 0.45; 95% CI, 0.23-0.86; P =.01). After additional adjustment for variables that contribute to heterogeneity and confounding within the propensity-matched group, surgical therapy remained significantly associated with a lower mortality (HR, 0.40; 95% CI, 0.18-0.91; P =.03). In this propensity-matched group, patients with moderate to severe congestive heart failure showed the greatest reduction in mortality with valve surgery (14% vs 51%; HR, 0.22; 95% CI, 0.09-0.53; P =.001). CONCLUSIONS: Valve surgery for patients with complicated, left-sided native valve endocarditis was independently associated with reduced 6-month mortality after adjustment for both baseline variables associated with the propensity to undergo valve surgery and baseline variables associated with mortality. The reduced mortality was particularly evident among patients with moderate to severe congestive heart failure.

Complicated left-sided native valve endocarditis in adults: risk classification for mortality.

CONTEXT: Complicated left-sided native valve endocarditis causes significant morbidity and mortality in adults. Lack of valid data regarding estimation of prognosis makes management of this condition difficult. OBJECTIVE: To derive and externally validate a prognostic classification system for adults with complicated left-sided native valve endocarditis. DESIGN, SETTING, AND PATIENTS: Retrospective observational cohort study conducted from January 1990 to January 2000 at 7 Connecticut hospitals among 513 patients older than 16 years who experienced complicated left-sided native valve endocarditis and who were divided into derivation (n = 259) and validation (n = 254) cohorts. MAIN OUTCOME MEASURE: All-cause mortality at 6 months after baseline. RESULTS: In the derivation and validation cohorts, the 6-month mortality rates were 25% and 26%, respectively. Five baseline features were independently associated with 6-month mortality (comorbidity [P =.03], abnormal mental status [P =.02], moderate to severe congestive heart failure [P =.01], bacterial etiology other than viridans streptococci [P<.001 except Staphylococcus aureus, P =.004], and medical therapy without valve surgery [P =.002]) and were used to create a prognostic classification system. In the derivation cohort, patients were classified into 4 groups with increasing risk for 6-month mortality: 5%, 15%, 31%, and 59% (P<.001). In the validation cohort, a similar risk among the 4 groups was observed: 7%, 19%, 32%, and 69% (P<.001). CONCLUSIONS: Adults with complicated left-sided native valve endocarditis can be accurately risk stratified using baseline features into 4 groups of prognostic severity. This prognostic classification system might be useful for facilitating management decisions.

The diagnostic accuracy of Kernig's sign, Brudzinski's sign, and nuchal rigidity in adults with suspected meningitis.

To determine the diagnostic accuracy of Kernig's sign, Brudzinski's sign, and nuchal rigidity for meningitis, 297 adults with suspected meningitis were prospectively evaluated for the presence of these meningeal signs before lumbar puncture was done. Kernig's sign (sensitivity, 5%; likelihood ratio for a positive test result [LR(+)], 0.97), Brudzinski's sign (sensitivity, 5%; LR(+), 0.97), and nuchal rigidity (sensitivity, 30%; LR(+), 0.94) did not accurately discriminate between patients with meningitis (>/=6 white blood cells [WBCs]/mL of cerebrospinal fluid [CSF]) and patients without meningitis. The diagnostic accuracy of these signs was not significantly better in the subsets of patients with moderate meningeal inflammation (>/=100 WBCs/mL of CSF) or microbiological evidence of CSF infection. Only for 4 patients with severe meningeal inflammation (>/=1000 WBCs/mL of CSF) did nuchal rigidity show diagnostic value (sensitivity, 100%; negative predictive value, 100%). In the broad spectrum of adults with suspected meningitis, 3 classic meningeal signs did not have diagnostic value; better bedside diagnostic signs are needed.