Ageing and infection

[Severe pneumococcal infections in the elderly - preventable by vaccination]

Elderly people are more susceptible to pneumococcal infections. Data in Germany from 2005-2010 shows that especially seniors are prone to develop serious complications such as sepsis. Women are obviously less affected than men. Most of the infections occurred during the winter months. The majority of isolates, i.e., about 80%, possess capsular polysaccharide antigens which are represented in the 23-valent vaccine. Consequently, it could be assumed that the severe complications ensuing long hospital stays and associated with a high mortality could have been avoided, if the elderly people would have been vaccinated, which, however, was only true in a small proportion (28%). Recently, a new conjugated vaccine was introduced to the market. In principle, several antibiotics are available for direct antibacterial treatment. All isolates are susceptible to cefotaxime as well as to ceftriaxone. Resistance to penicillin as well as ampicillin is very rare in Germany. The vast majority of isolates are susceptible to quinolones such as levofloxacin and moxifloxacin. Resistance to macrolides, for example to erythromycin, occurs to a certain extent but the percentage has been declining in recent years. Nevertheless, in many instances therapy is too late. Thus, prevention is of great importance.

The safety of a "fast-track" program after laparoscopic colorectal surgery is comparable in older patients as in younger patients

INTRODUCTION

Fast-track protocols, introduced in the late 1990 s, have been applied in several surgical fields, particularly for colorectal surgery. However, currently many surgical patients are elderly, and discussion about the application of such programs for elderly patients is lacking. The present study was designed to assess the safety of application of a fast-track program after laparoscopic colorectal surgery in elderly patients.

METHODS

From August 2009 to January 2011, we prospectively collected data from patients who underwent laparoscopic colorectal surgery with a perioperative fast-track program. The data of patients older and younger than 70 years were compared.

RESULTS

Of a total of 337 patients, the group of patients older than 70 years (OG) totaled 87 (25.8 %) and the younger group (YG) totaled 250 (74.2 %). Ten patients (11.5 %) were excluded in the OG and 24 (9.6 %) in the YG. There were no differences in gender, history of previous surgeries, body mass index, type of operation, operative time, or blood loss between groups. Age (74.8 vs. 56.7 years, p < 0.001), presence of comorbidities (70.1 vs. 44.7 %, p < 0.001), and ASA score (I:II:III, 33.8:57.1:9.1 vs. 60.6:33.2:6.2 %, p < 0.001) were significantly different between the two groups. Postoperative course did not show differences, including return of flatus, stool passage, advancement of diet, removal of urinary catheter, length of usage of IV antibiotics, complications, and length of postoperative stay. Emergency department visits or readmission within a month after discharge were more frequent in the OG (11.7 %) than the YG (4 %; p = 0.013).

CONCLUSIONS

Fast-track after laparoscopic colorectal surgery can be safely applied in carefully selected elderly patients older than age 70 years. Physicians should keep in mind complications that may present after discharge and should actively educate patients about them.

Reduced release and binding of perforin at the immunological synapse underlies the age-related decline in natural killer cell cytotoxicity

Physiological aging is accompanied by a marked reduction in natural killer (NK) cell cytotoxicity (NKCC) at the single cell level, but the underlying mechanisms are unknown. To address this issue, we isolated NK cells from healthy young (≤ 35 years) and old (≤ 60 years) subjects and examined the effect of age on events fundamental to the process of NKCC. Simultaneous assessment of NKCC and NK cell-target cell conjugate formation revealed a marked age-associated decline in NK cell killing but comparable conjugate formation, indicating a post-target cell binding defect was responsible for impaired NKCC. Despite a reduction in the proportion of NK cells expressing the activatory receptor NKp46, NK cells from old donors were not hyporesponsive to stimulation, as no age-associated difference was observed in the expression of the early activation marker CD69 following target cell coculture. Furthermore, intracellular levels of the key cytotoxic effector molecules perforin and granzyme B, and the fusion of secretory lysosomes with the NK cell membrane were also similar between the two groups. However, when we examined the binding of the pore-forming protein perforin to the surface of its target cell, an event that correlated strongly with target cell lysis, we found the percentage of perforin positive target cells was lower following coculture with NK cells from old subjects. Underlying this reduction in binding was an age-associated impairment in perforin secretion, which was associated with defective polarization of lytic granules towards the immunological synapse. We propose that reduced perforin secretion underlies the reduction in NKCC that accompanies physiological aging.

Efficacy and safety of anidulafungin in elderly, critically ill patients with invasive Candida infections: a post hoc analysis

Post hoc analysis of a non-comparative, prospective, multicentre, phase IIIb study was performed to compare efficacy and safety of anidulafungin in elderly (≥65 years) versus non-elderly (<65 years) Intensive Care Unit (ICU) patients with candidaemia/invasive candidiasis (C/IC). Adult ICU patients with confirmed C/IC meeting ≥1 of the following criteria were enrolled: post-abdominal surgery; solid tumour; renal/hepatic insufficiency; solid organ transplantation; neutropenia; age ≥65 years. Patients received anidulafungin (200 mg on Day 1, 100 mg/day thereafter) for ≥10 days followed by optional azole step-down therapy for a total treatment duration of 14-56 days. The primary efficacy endpoint was global (clinical and microbiological) response at the end of all therapy (EOT). Primary efficacy analysis was performed in the modified intent-to-treat (mITT) population (n=170), excluding unknown and missing responses. In total, 80 patients (47.1%) were aged ≥65 years and 90 (52.9%) were aged <65 years; the mean age difference between the two groups was 21.9 years. Global success at EOT in mITT patients was similar in elderly (68.1%) and non-elderly (70.7%) patients (P=0.719). However, global success rates were significantly lower in elderly versus non-elderly patients at 2 and 6 weeks after EOT (P=0.045 and P=0.016, respectively). Ninety-day survival was significantly lower (P=0.006) for elderly (42.8%) versus non-elderly patients (63.3%). The incidence and profile of adverse events were similar in elderly and non-elderly patients. Anidulafungin was effective and safe for treatment of C/IC in elderly ICU patients, despite higher baseline severity of illness scores.

Immunoprotective effects of oral intake of heat-killed Lactobacillus pentosus strain b240 in elderly adults: a randomised, double-blind, placebo-controlled trial

Oral intake of Lactobacillus pentosus strain b240 (b240) has been shown to enhance the secretion of salivary secretory IgA in elderly adults. However, its clinical benefits remain to be determined. We tested the hypothesis that b240 exerts a protective effect against the common cold in elderly adults. The design of the present study was a randomised, double-blind, placebo-controlled trial (RCT) with parallel three-group comparison. For this purpose, 300 eligible elderly adults were randomly allocated to one of three groups, namely a placebo, low-dose or high-dose b240 group. Participants in the low-dose and high-dose b240 groups were given tablets containing 2 × 10(9) or 2 × 10(10) cells, respectively, of heat-killed b240, while those in the placebo group were given tablets without b240. Each group consumed their respective tablets once daily for 20 weeks. The common cold was assessed on the basis of a diary. Change in quality of life was evaluated using the SF-36. Of the total participants, 280 completed the 20-week RCT. The accumulated incidence rate of the common cold was 47·3, 34·8 and 29·0 % for the placebo, low-dose b240 and high-dose b240 groups, respectively (P for trend = 0·012). Lower incidence rates were consistently observed throughout the experimental period in the b240 groups (log-rank test, P= 0·034). General health perception, as determined by the SF-36®, dose-dependently increased in the b240 groups ( P <0·025). In conclusion, oral intake of b240 significantly reduced the incidence rate of the common cold in elderly adults, indicating that b240 might be useful in improving resistance against infection through mucosal immunity.

Vaccines for the elderly

Vaccination is the most efficient strategy to prevent infectious disease. The increased vulnerability to infection of the elderly makes them a particularly important target population for vaccination. However, most vaccines are less immunogenic and efficient in the elderly because of age-related changes in the immune system. Vaccination against influenza, Streptococcus pneumoniae and varicella zoster virus is recommended for the elderly in many countries. Various strategies such as the use of adjuvants and novel administration routes are pursued to improve influenza vaccination for the elderly and recent developments in the field of pneumococcal vaccination led to the licensure of protein-conjugated polysaccharide vaccines containing up to 13 serotypes. As antibody titres are generally lower in the elderly and-particularly for inactivated vaccines-decline fast in the elderly, regular booster immunizations, for example against tetanus, diphtheria and, in endemic areas, tick-borne encephalitis, are essential during adulthood to ensure protection of the elderly. With increasing health and travel opportunities in old age the importance of travel vaccines for persons over the age of 60 is growing. However, little is known about immunogenicity and efficacy of travel vaccines in this age group. Despite major advances in the field of vaccinology over the last decades, there are still possibilities for improvement concerning vaccines for the elderly. Novel approaches, such as viral vectors for antigen delivery, DNA-based vaccines and innovative adjuvants, particularly toll-like receptor agonists, will help to achieve optimal protection against infectious diseases in old age.

Foodborne and waterborne infections in elderly community and long-term care facility residents,Victoria, Australia

We calculated rates of foodborne and waterborne infections reported to the health department in Victoria, Australia, during 2000-2009 for elderly residents of long-term care facilities (LTCFs) and the community. We used negative binomial regression to estimate incidence rate ratios, adjusting for age, sex, and reporting period. We analyzed 8,277 infections in elderly persons. Rates of campylobacteriosis, legionellosis, listeriosis, toxigenic Escherichia coli infections, and shigellosis were higher in community residents, and rates of Salmonella infection were higher in LTCF residents. Each year, 61.7 Campylobacter infections were reported per 100,000 LTCF residents, compared with 97.6 per 100,000 community residents. LTCF residents were at higher risk for S. enterica serotype Typhimurium associated with outbreaks. Rates of foodborne infections (except salmonellosis) were similar to or lower for LTCF residents than for community residents. These findings may indicate that food preparation practices in LTCFs are safer than those used by elderly persons in the community.

The effect of chronological age on the inflammatory response of human fibroblasts

The immune system undergoes profound age-related changes, including a gradual increase in the production and circulation of proinflammatory cytokines. Despite the known capacity of fibroblasts to produce cytokines, little is known so far about the inflammatory response of fibroblasts to cellular stress such as viral and/or bacterial infection in the context of aging. Therefore the aim of this study was to analyze the levels of IL6 and IL8 secretion in supernatants of human skin fibroblasts from young and elderly persons. Cytokine and chemokine secretion was analyzed before and after in vitro infection of the cells with Cytomegalovirus (CMV) and/or stimulation with Lipopolysaccharide (LPS). The exposure of fibroblasts to these agents caused inflammatory changes, reflected by the secretion of both the cytokine IL6 and the chemokine IL8 by fibroblasts from young as well as elderly persons. The cytokine/chemokine production induced by either agent alone could be further increased by co-stimulation of the cells with both stimuli. The level of protein secretion was dependent on the chronological age of the fibroblasts. Stimulated human skin fibroblasts from elderly donors produced higher amounts of IL6 as well as IL8 than fibroblasts from young donors. These differences were more pronounced for IL6 than for IL8. The inflammatory response of fibroblasts to stimulation differed among donors and did not correspond to the responsiveness of whole blood derived from the same person.

In summary lifelong CMV-infection may act as an in vivo trigger for inflammatory changes by increasing the inflammatory response to bacterial products such as LPS. It may thus contribute to age-related inflammatory processes, referred to as ‘inflamm-aging’.

A short-term, multicomponent infection control program in nursing homes: a cluster randomized controlled trial

OBJECTIVES

To assess the impact of a hygiene-encouragement program on reducing infection rates (primary end point) by 5%.

DESIGN

A cluster randomized study was carried out over a 5-month period.

SETTINGS AND PARTICIPANTS

Fifty nursing homes (NHs) with 4345 beds in France were randomly assigned by stratified-block randomization to either a multicomponent intervention (25 NHs) or an assessment only (25 NHs).

INTERVENTION

The multicomponent intervention was targeted to caregivers and consisted of implementing a bundle of infection prevention consensual measures. Interactive educational meetings using a slideshow were organized at the intervention NHs. The NHs were also provided with color posters emphasizing hand hygiene and a kit that included hygienic products such as alcoholic-based hand sanitizers. Knowledge surveys were performed periodically and served as reminders.

MEASUREMENTS

The primary end point was the total infection rate (urinary, respiratory, and gastrointestinal infections) in those infection cases classified either as definite or probable. Analyses corresponded to the underlying design and were performed according to the intention-to-treat principle. This study was registered (#NCT01069497).

RESULTS

Forty-seven NHs (4515 residents) were included and followed. The incidence rate of the first episode of infection was 2.11 per 1000 resident-days in the interventional group and 2.15 per 1000 resident-days in the control group; however, the difference between the groups did not reach statistical significance in either the unadjusted (Hazard Ratio [HR] = 1.00 [95% confidence interval (CI) 0.89-1.13]; P = .93]) or the adjusted (HR = 0.99 [95% CI 0.87-1.12]; P = .86]) analysis.

CONCLUSION

Disentangling the impact of this type of intervention involving behavioral change in routine practice in caregivers from the prevailing environmental and contextual determinants is often complicated and confusing to interpret the results.

Immunosenescence and herd immunity: with an ever-increasing aging population do we need to rethink vaccine schedules?

Vaccination is a powerful public health tool that has been of tremendous benefit in protecting vulnerable populations from specific infections. Moreover, in addition to the direct benefits to vaccinated individuals, the indirect effects of protection at the community level have also been demonstrated and termed 'herd immunity'. The predicted demographic shift in the population landscape towards an ever-increasing aging population and the evidence suggesting that older individuals produce less-than-optimal vaccine responses have raised the question of rethinking vaccine schedules. This article provides evidence that even if herd immunity might be an option to indirectly protect the aging and aged adult population, the highest priorities for the near future must be to understand how vaccine responses in older individuals can be improved, to break down the public, cultural, societal and political barriers to vaccination and to counter the antivaccination movement that inhibits the worldwide spread of lifelong immunization programs.

Balancing the Efficacy and Safety of Vaccines in the Elderly

With advances in global health care, ageing populations are expected to grow worldwide throughout the 21^st century. Increased lifespan is a testament to modern medical and social practices, but also presents a growing challenge to a system with limited resources. Elderly populations present specific concerns related to preventative health practices, especially vaccination. Although the power of vaccination is unquestionable in controlling infectious disease, immunosenescence can lead to reduced immune responses following immunization in the elderly, and increased morbidity and mortality. Further complicating this issue, some vaccines themselves may pose a substantial safety risk in the elderly when compared to younger counterparts. Though any health care intervention must balance risk and reward, safety and immunogenicity are often poorly characterized in older populations. This review explores several domestic and travel vaccines, examining what is known concerning efficacy and safety in the elderly, and considers future alternatives.

How should we investigate CUO (C-Reactive Protein elevation of unknown origin)? A case-based discussion of infective endocarditis in an octogenarian

Infective endocarditis and other chronic infections may cause diagnostic difficulties, regardless of age. The likelihood of an atypical presentation of chronic infection probably increases with age. Serum CRP may be a useful guide to the presence of underlying infection and its resolution in older people. The term CUO (CRP elevation of unknown origin) may have a place in triggering further investigation for the presence of infection or other pathology.

Severe sepsis and its impact on outcome in elderly and very elderly patients admitted in intensive care unit

BACKGROUND

Elderly patients comprise an increasing proportion of intensive care unit (ICU) admissions. Advanced age and multiple comorbidities compromise their immunity and hence they may be more prone to succumbing to severe infection and have poorer outcome. We undertook this study to review impact of severe sepsis on mortality in the elderly patients.

METHODS

All patients admitted to a medical ICU of a tertiary care institute with severe sepsis or septic shock were prospectively included. Patients were divided into young (age below 60 years), old (age between 60 and 80 years), and very old (age above 80 years) groups. Data regarding baseline patient characteristics, admission APACHE II score, and ICU course including need for organ support and ICU length of stay were noted. Categorical data were analyzed using χ(2) or Fisher Exact test as appropriate and continuous data were analyzed using Student t test. Primary outcome measure was the ICU mortality.

RESULTS

Of 387 patients with sepsis, 132 patients who fulfilled the criteria for severe sepsis/septic shock were included in the analysis. The most common suspected site of infection was lungs (45.5%), followed by urinary tract (21.2%) and abdomen (16.7%). Intensive care unit mortality in younger patients was 45.6% as compared to 60.7% in old and 78.9% in very old patients (P = .035). The relative risk (RR) for dying in the old age was 1.125 and RR for dying in the very old age group was 1.487 as compared to the young patients. There was an increased need for organ support in the elderly and very elderly population as compared to the younger population. On multivariate analysis, only age of the patient was found to be independently predicting ICU mortality (P = .002, OR: 1.038, 95% CI: 1.014-1.062).

CONCLUSIONS

The risk of dying from severe sepsis is considerably higher in the elderly and very elderly subgroup of patients with age as an independent risk factor for mortality. Hence, early aggressive care to recognize and manage severe sepsis is required to improve outcome.

Severe Sepsis and its Impact on Outcome in Elderly and Very Elderly Patients Admitted in Intensive Care Unit

Received October 7, 2010, and in revised form November 10, 2010. Accepted for publication December 7, 2010. Background: Elderly patients comprise an increasing proportion of intensive care unit (ICU) admissions. Advanced age and multiple comorbidities compromise their immunity and hence they may be more prone to succumbing to severe infection and have poorer outcome. We undertook this study to review impact of severe sepsis on mortality in the elderly patients. Methods: All patients admitted to a medical ICU of a tertiary care institute with severe sepsis or septic shock were prospectively included. Patients were divided into young (age below 60 years), old (age between 60 and 80 years), and very old (age above 80 years) groups. Data regarding baseline patient characteristics, admission APACHE II score, and ICU course including need for organ support and ICU length of stay were noted. Categorical data were analyzed using χ 2 or Fisher Exact test as appropriate and continuous data were analyzed using Student t test. Primary outcome measure was the ICU mortality. Results: Of 387 patients with sepsis, 132 patients who fulfilled the criteria for severe sepsis/septic shock were included in the analysis. The most common suspected site of infection was lungs (45.5%), followed by urinary tract (21.2%) and abdomen (16.7%). Intensive care unit mortality in younger patients was 45.6% as compared to 60.7% in old and 78.9% in very old patients ( P = .035). The relative risk (RR) for dying in the old age was 1.125 and RR for dying in the very old age group was 1.487 as compared to the young patients. There was an increased need for organ support in the elderly and very elderly population as compared to the younger population. On multivariate analysis, only age of the patient was found to be independently predicting ICU mortality ( P = .002, OR: 1.038, 95% CI: 1.014-1.062). Conclusions: The risk of dying from severe sepsis is considerably higher in the elderly and very elderly subgroup of patients with age as an independent risk factor for mortality. Hence, early aggressive care to recognize and manage severe sepsis is required to improve outcome.

Comparative safety of infliximab and etanercept on the risk of serious infections: does the association vary by patient characteristics?

PURPOSE

Infliximab, a chimeric monoclonal anti-TNFα antibody, has been found to increase the risk of serious infections compared with the TNF receptor fusion protein etanercept in some studies. It is unclear whether the risk varies by patient characteristics. We conducted a study to address this question.

METHODS

We identified members of Kaiser Permanente Northern California who initiated infliximab (n = 793) or etanercept (n = 2692) in 1997-2007. Using a Cox model, we estimated the propensity-score-adjusted hazard ratio (HR) and 95% confidence interval (CI) of serious infections requiring hospitalization or opportunistic infections comparing infliximab initiators to etanercept initiators. We tested whether the adjusted HR differed by age, sex, race/ethnicity, body mass index, and smoking status.

RESULTS

The crude incidence rate of serious infections per 100 person-years was 5.4 (95%CI: 3.8, 7.5) in patients <65 years and 16.0 (95%CI: 10.4, 23.4) in patients ≥ 65 years during the first 3 months following treatment initiation. Compared with etanercept, the adjusted HR during this period was elevated for infliximab in patients <65 years (HR: 3.01; 95%CI: 1.49, 6.07), but not in those ≥ 65 years (HR 0.94; 95%CI: 0.41, 2.13). Findings did not suggest that the HR varied by the other patient characteristics examined.

CONCLUSIONS

An increased risk of serious infections associated with infliximab relative to etanercept did not appear to be modified by patients' sex, race/ethnicity, body mass index, or smoking status. There was an indication that the increased risk might be limited to patients <65 years. Additional studies are warranted to verify or refute this finding.

Effectiveness of influenza vaccine in aging and older adults: comprehensive analysis of the evidence

Foremost amongst the diseases preventable by vaccination is influenza. Worldwide, influenza virus infection is associated with serious adverse events leading to hospitalization, debilitating complications, and death in elderly individuals. Immunization is considered to be the cornerstone for preventing these adverse health outcomes, and vaccination programs are timed to optimize protection during the annual influenza season. Trivalent inactivated influenza virus vaccines are believed to be both effective and cost-saving; however, in spite of widespread influenza vaccination programs, rates of hospitalization for acute respiratory illness and cardiovascular diseases have been increasing in this population during recent annual influenza seasons. From meta-analyses summarizing estimates of influenza vaccine effectiveness from available observational clinical studies, this review aims to examine how effective current influenza vaccine strategies are in the aging and older adult population and to analyze which are the most important biases that interfere with measurements of influenza vaccine effectiveness. Furthermore, consideration is given to strategies that should be adopted in order to optimize influenza vaccine effectiveness in the face of immune exhaustion.

Severe sepsis and septic shock in the elderly: An overview

The incidence of severe sepsis and septic shock is increasing in the older population leading to increased admissions to the intensive care units (ICUs). The elderly are predisposed to sepsis due to co-existing co-morbidities, repeated and prolonged hospitalizations, reduced immunity, functional limitations and above all due to the effects of aging itself. A lower threshold and a higher index of suspicion is required to diagnose sepsis in this patient population because the initial clinical picture may be ambiguous, and aging increases the risk of a sudden deterioration in sepsis to severe sepsis and septic shock. Management is largely based on standard international guidelines with a few modifications. Age itself is an independent risk factor for death in patients with severe sepsis, however, many patients respond well to timely and appropriate interventions. The treatment should not be limited or deferred in elderly patients with severe sepsis only on the grounds of physician prejudice, but patient and family preferences should also be taken into account as the outcomes are not dismal. Future investigations in the management of sepsis should not only target good functional recovery but also ensure social independence and quality of life after ICU discharge.

Severe sepsis and septic shock in the elderly: An overview

The incidence of severe sepsis and septic shock is increasing in the older population leading to increased admissions to the intensive care units (ICUs). The elderly are predisposed to sepsis due to co-existing co-morbidities, repeated and prolonged hospitalizations, reduced immunity, functional limitations and above all due to the effects of aging itself. A lower threshold and a higher index of suspicion is required to diagnose sepsis in this patient population because the initial clinical picture may be ambiguous, and aging increases the risk of a sudden deterioration in sepsis to severe sepsis and septic shock. Management is largely based on standard international guidelines with a few modifications. Age itself is an independent risk factor for death in patients with severe sepsis, however, many patients respond well to timely and appropriate interventions. The treatment should not be limited or deferred in elderly patients with severe sepsis only on the grounds of physician prejudice, but patient and family preferences should also be taken into account as the outcomes are not dismal. Future investigations in the management of sepsis should not only target good functional recovery but also ensure social independence and quality of life after ICU discharge.

Aging of the human metaorganism: the microbial counterpart

Human beings have been recently reviewed as 'metaorganisms' as a result of a close symbiotic relationship with the intestinal microbiota. This assumption imposes a more holistic view of the ageing process where dynamics of the interaction between environment, intestinal microbiota and host must be taken into consideration. Age-related physiological changes in the gastrointestinal tract, as well as modification in lifestyle, nutritional behaviour, and functionality of the host immune system, inevitably affect the gut microbial ecosystem. Here we review the current knowledge of the changes occurring in the gut microbiota of old people, especially in the light of the most recent applications of the modern molecular characterisation techniques. The hypothetical involvement of the age-related gut microbiota unbalances in the inflamm-aging, and immunosenescence processes will also be discussed. Increasing evidence of the importance of the gut microbiota homeostasis for the host health has led to the consideration of medical/nutritional applications of this knowledge through the development of probiotic and prebiotic preparations specific for the aged population. The results of the few intervention trials reporting the use of pro/prebiotics in clinical conditions typical of the elderly will be critically reviewed.

Influenza vaccination in the face of immune exhaustion: is herd immunity effective for protecting the elderly?

At the start of the 21st century, seasonal influenza virus infection is still a major public health concern across the world. The recent body of evidence confirms that trivalent inactivated influenza vaccines (TIVs) are not optimal within the population who account for approximately 90% of all influenza-related death: elderly and chronically ill individuals regardless of age. With the ever increasing aging of the world population and the recent fears of any pandemic influenza rife, great efforts and resources have been dedicated to developing more immunogenic vaccines and strategies for enhancing protection in these higher-risk groups. This paper describes the mechanisms that shape immune response at the extreme ages of life and how they have been taken into account to design more effective immunization strategies for these vulnerable populations. Furthermore, consideration will be given to how herd immunity may provide an effective strategy in preventing the burden of seasonal influenza infection within the aged population.

Current evidence on intradermal influenza vaccines administered by Soluvia™ licensed micro injection system

Among the several strategies explored for (1) the enhancement of the immune response to influenza immunization, (2) the improvement of the vaccine acceptability and (3) the overcoming of the egg-dependency for vaccine production, intradermal administration of influenza vaccine emerges as a promising alternative to conventional intramuscular route, thanks to the recent availability of new delivery devices and the perception of advantages in terms of immunogenicity, safety, reduction of antigen content and acceptability.

 

Data from clinical trials performed in children, adults <60 y and elderly people and post-marketing surveillance demonstrate that actually, licensed intradermal influenza vaccines, Intanza™ 9 and 15 µg and Fluzone™ Intradermal, administered by the microinjection system Soluvia™, show an excellent acceptability, tolerability and safety profile. Formulations containing 9 and 15 μg per strain demonstrate, respectively, comparable and superior immunogenicity than conventional intramuscular vaccines. Licensed intradermal influenza vaccines can be considered a valid alternative to standard intramuscular vaccination offering significant advantages in low-responder populations and helping to increase influenza vaccination coverage rates especially in people with fear of needles or high apprehension associated with annual vaccination.

Aging and asthma - changes in CD45RA, CD29 and CD95 T cells subsets

BACKGROUND

Aging is associated with thymus involution leading to a reduction in naive T cells and to an accumulation of effector-memory cells. Apoptosis is a key mechanism to clear the immune system from activated and harmful cells. In asthma the stimulation of T cells by environmental antigens can decrease naive cells and sustain activated cells. The aim of this work was to evaluate the imbalance between CD45RA and CD29 cells during the aging process and their changes in elderly asthma and to evaluate how elderly and chronic diseases like asthma can affect susceptibility to apoptosis.

METHODS

Elderly and young adult healthy volunteers and elderly asthmatic patients were submitted to skin prick tests, immunoglobulin determination and flow cytometry analyses of CD3, CD4, CD8, CD45RA, CD29, and CD95.

RESULTS

Serum IgE was increased in allergic patients (p=0.0001). Asthmatics presented an increase in CD4 cells (p<0.05). CD45RA was significantly decreased in elderly individuals (p<0.05) and this decrease was higher in asthmatics (p<0.05). CD29 was increased in elderly healthy individuals compared to the control young group (p=0.0001). A negative correlation between CD29 and CD45RA (p<0.05) was observed. CD95 lymphocytes increased in elderly (p=0.0001) and a positive correlation between age and CD95 (p<0.05) was found. Asthmatic patients showed significant decreases in CD95 (p=0. 0001).

CONCLUSIONS

Naive cells are key cells in the defence against infections and their decrease in the elderly and in asthma is a bad prognosis factor. The reduction of apoptosis markers can promote the persistence of activated cells involved in chronic conditions.

Interpretation of hormone levels in older patients: points for consideration

Blood hormone and tumor marker concentrations are usually determined by immunochemical methods which are based on an unique reaction between antigen and assay capture antibody. Despite the speed and simplicity of assays performance on automatic immunochemistry platforms, the interpretation of final results requires a deep knowledge of method fallibility. General lack of immunoassays standardization, presence of cross-reacting substances in patient's sample, limitation of free hormones measurement due to abnormal analyte binding protein concentrations, assay interferences due to patient's autoantibodies, and heterophilic antibodies, as well as proper interpretation of very low- and very high-sample analyte levels, are the main points discussed in respect to hormones and tumor markers measurement in geriatric population.

Diagnostic challenges and opportunities in older adults with infectious diseases

Infections remain a major threat to the well-being of our growing aged population. The correct and timely diagnosis of infections in older adults is increasingly important in the current age of antimicrobial resistance. Urinary tract infection, pneumonia, and bacteremia present particular challenges. In older patients with bacteremia, blood cultures have comparable yield as compared with younger patients. However, the routine triggers for ordering blood cultures may not be appropriate in older adults. In addition, resistance patterns of isolated pathogens may change with age. The main difficulties in diagnosing urinary tract infections in older adults are caused by an increased prevalence of asymptomatic bacteriuria and frequent use of urinary catheters. However, a combined noninvasive approach that includes history, physical examination, urinary dipstick testing, urine cultures, and simple blood tests can provide direction. In addition, specific guidelines for specific populations are available. In older patients suspected of bacterial pneumonia, bedside pulse oximetry and urinary antigen testing for Streptococcus pneumoniae and Legionella pneumophila provide direction for the clinician. Although infected older adults pose specific and unique diagnostic challenges, a thorough history and physical examination combined with minimally invasive testing will lead to the correct diagnosis in most older adults with infectious diseases, limiting the need for empiric antibiotics in this age group.

Melatonin is able to delay endoplasmic reticulum stress-induced apoptosis in leukocytes from elderly humans

The mechanisms regulating neutrophil apoptosis are basically unaffected by the aging process. However, a significant impairment of cell survival occurs in elderly individuals following neutrophil challenge with pro-inflammatory stimuli, such as granulocyte-macrophage colony-stimulating factor (GM-CSF). The goal of the present study was to prove the effects of melatonin supplementation on apoptosis induced by calcium signaling in human leukocytes from elderly volunteers. Treatments with the specific inhibitor of cytosolic calcium re-uptake, thapsigargin, and/or the calcium mobilizing agonist, N-formyl-methionyl-leucyl-phenylalanine (fMLP), induced mitochondrial membrane depolarization, caspase activation, phosphatidylserine (PS) externalization, and DNA fragmentation in leukocytes from both young and elderly volunteers, although such effects were much more evident in aged leukocytes. Importantly, melatonin treatment substantially preserved mitochondrial membrane potential, reversed caspase activation, reduced PS exposure and forestalled DNA fragmentation in leukocytes from both age groups. In conclusion, melatonin is able to delay endoplasmic reticulum stress-induced apoptosis in aged leukocytes and may counteract, at the cellular level, age-related degenerative phenomena linked to oxidative stress.

Food safety informatics: a public health imperative

To date, little has been written about the implementation of utilizing food safety informatics as a technological tool to protect consumers, in real-time, against foodborne illnesses. Food safety outbreaks have become a major public health problem, causing an estimated 48 million illnesses, 128,000 hospitalizations, and 3,000 deaths in the U.S. each year. Yet, government inspectors/regulators that monitor foodservice operations struggle with how to collect, organize, and analyze data; implement, monitor, and enforce safe food systems. Currently, standardized technologies have not been implemented to efficiently establish "near-in-time" or "just-in-time" electronic awareness to enhance early detection of public health threats regarding food safety. To address the potential impact of collection, organization and analyses of data in a foodservice operation, a wireless food safety informatics (FSI) tool was pilot tested at a university student foodservice center. The technological platform in this test collected data every six minutes over a 24 hour period, across two primary domains: time and temperatures within freezers, walk-in refrigerators and dry storage areas. The results of this pilot study briefly illustrated how technology can assist in food safety surveillance and monitoring by efficiently detecting food safety abnormalities related to time and temperatures so that efficient and proper response in "real time" can be addressed to prevent potential foodborne illnesses.

Heightened uterine mammalian target of rapamycin complex 1 (mTORC1) signaling provokes preterm birth in mice

Although preterm delivery is a major global health issue, its causes and underlying mechanism remain elusive. Using mutant mice, mimicking aspects of human preterm birth, we show here that uterine decidual senescence early in pregnancy via heightened mammalian target of rapamycin complex 1 (mTORC1) signaling is a significant contributor of preterm birth and fetal death, and that these adverse phenotypes are rescued by a low dose of rapamycin, an inhibitor of mTORC1 signaling. This role of mTORC1 signaling in determining the timing of birth in mice may help us better understand the mechanism of the timing of birth in humans and develop new and improved strategies to combat the global problem of preterm birth.

Risk factors and mortality for nosocomial bloodstream infections in elderly patients

OBJECTIVE

To determine risk factors for nosocomial bloodstream infection (BSI) and associated mortality in geriatric patients in geriatric and internal medicine wards at a university hospital.

METHODS

Single-center retrospective (1992-2007), pairwise-matched (1:1-ratio) cohort study. Geriatric patients with nosocomial BSI were matched with controls without BSI on year of admission and length of hospitalization before onset of BSI. Demographic, microbiological, and clinical data are collected.

RESULTS

One-hundred forty-two BSI occurred in 129 patients. Predominant microorganisms were Escherichia coli (23.2%), coagulase-negative Staphylococci (19.4%), Pseudomonas aeruginosa (8.4%), Staphylococcus aureus (7.1%), Klebsiella pneumoniae (5.8%) and Candida spp. (5.8%). Matching was successful for 109 cases. Compared to matched control subjects, cases were more frequently female, suffered more frequently from arthrosis, angina pectoris and pressure ulcers, had worse Activities of Daily Living-scores, had more often an intravenous or bladder catheter, and were more often bedridden. Logistic regression demonstrated presence of an intravenous catheter (odds ratio [OR] 7.5, 95% confidence interval [CI] 2.5-22.9) and being bedridden (OR 2.9, 95% CI 1.6-5.3) as independent risk factors for BSI. In univariate analysis nosocomial BSI was associated with increased mortality (22.0% vs. 11.0%; P=0.029). After adjustment for confounding co-variates, however, nosocomial BSI was not associated with mortality (hazard ratio 1.3, 95% CI 0.6-2.6). Being bedridden and increasing age were independent risk factors for death.

CONCLUSION

Intravenous catheters and being bedridden are the main risk factors for nosocomial BSI. Although associated with higher mortality, this infectious complication seems not to be an independent risk factor for death in geriatric patients.

Immunogenicity and safety of ZOSTAVAX(®) approaching expiry potency in individuals aged ≥50 years

BACKGROUND

Age is a major risk factor for herpes zoster (HZ) and its potential long-term complication post-herpetic neuralgia (PHN). Due to the significant burden of HZ and PHN on patients' quality of life, it is vital that effective and well-tolerated vaccines are available to prevent HZ in older adults. ZOSTAVAX(®) vaccine was developed to prevent HZ and PHN in individuals ≥50 years (y) of age, and its clinical efficacy and safety have been demonstrated.

AIMS AND METHODS

This phase 4, open-label, multicenter study was undertaken to assess the immunogenicity and safety of a single dose of ZOSTAVAX (refrigerator-stable formulation) given within 6 mo of its expiry date in individuals ≥50 y of age. The geometric mean fold rise (GMFR) from pre-vaccination to 4 weeks post-vaccination in varicella zoster virus (VZV) antibody titers was calculated. An acceptable antibody response was defined as a lower 95% confidence interval (CI) of GMFR > 1.4. Solicited and unsolicited injection-site reactions and systemic adverse events were recorded.

RESULTS

The GMFR in VZV antibody titers was 3.1 (95% CI: 2.6, 3.8), satisfying the criterion for an acceptable VZV antibody response to ZOSTAVAX (minimum requirement: 1.4 GMFR). An acceptable rise in VZV antibody titers was observed in individuals of 50-59 y of age (GMFR 3.9; 95% CI: 2.9, 5.1) and in those ≥60 y of age (GMFR 2.5; 95% CI: 1.9, 3.2). ZOSTAVAX was well tolerated; no serious adverse events were reported.

CONCLUSION

ZOSTAVAX elicits an acceptable immune response in immunocompetent individuals ≥50 y of age when stored as directed and administered during the 6 mo prior to expiration.

Taking stock of infections and antibiotic resistance in the elderly and long-term care facilities: A survey of existing and upcoming challenges

Treating elderly patients with infections represents one of the greatest challenges to health-care providers. Older adults are the largest growing sector of the population and suffer excessively from infectious diseases such as pneumonia, urinary tract infections (UTIs), and skin and soft-tissue infections. Often because of disabilities, the elderly require treatment of infectious diseases in long-term care facilities (LTCFs). As a result of antibiotic use, LTCFs have become "reservoirs of resistance" and multi-drug resistant (MDR) pathogens are frequently recovered. Clinicians also need to be aware of the impairment of immune function and other emerging chronic infections (HIV, HCV) that are now present in the elderly. Despite vigilance regarding this issue, delays in diagnosis and initiation of therapy are common. This article reviews the changing landscape of infections in the elderly and the challenge these syndromes present in the context of an increasing older population that requires dedicated resources.

Return of inactivated whole-virus vaccine for superior efficacy

The swine, influenza, H1N1 outbreak in 2009 highlighted the inadequacy of the currently used antibody-based vaccine strategies as a preventive measure for combating influenza pandemics. The ultimate goal for successful control of newly arising influenza outbreaks is to design a single-shot vaccine that will provide long-lasting immunity against all strains of influenza A virus. A large amount of data from animal studies has indicated that the cross-reactive cytotoxic T (Tc) cell response against conserved influenza virus epitopes may be the key immune response needed for a universal influenza vaccine. However, decades of research have shown that the development of safe T-cell-based vaccines for influenza is not an easy task. Here, I discuss the overlooked but potentially highly advantageous inactivation method, namely, γ-ray irradiation, as a mean to reach the Holy Grail of influenza vaccinology.

Persistent viral infections and immune aging

Immunosenescence comprises a set of dynamic changes occurring to both, the innate as well as the adaptive immune system that accompany human aging and result in complex manifestations of still poorly defined deficiencies in the elderly population. One of the most prominent alterations during aging is the continuous involution of the thymus gland which is almost complete by the age of 50. Consequently, the output of naïve T cells is greatly diminished in elderly individuals which puts pressure on homeostatic forces to maintain a steady T cell pool for most of adulthood. In a great proportion of the human population, this fragile balance is challenged by persistent viral infections, especially Cytomegalovirus (CMV), that oblige certain T cell clones to monoclonally expand repeatedly over a lifetime which then occupy space within the T cell pool. Eventually, these inflated memory T cell clones become exhausted and their extensive accumulation accelerates the age-dependent decline of the diversity of the T cell pool. As a consequence, infectious diseases are more frequent and severe in elderly persons and immunological protection following vaccination is reduced. This review therefore aims to shed light on how various types of persistent viral infections, especially CMV, influence the aging of the immune system and highlight potential measures to prevent the age-related decline in immune function.

Vaccine effectiveness in older individuals: what has been learned from the influenza-vaccine experience

Vaccination policies in most high-income countries attempt to reduce the adverse impact of influenza targeting people aged at least 60 years. However, while it is widely believed that the current immunization strategy saves many lives, influenza infection still remains a severe burden in aged individuals leading to a wide debate on the exact magnitude of the benefit of vaccination in this population. The first aim of the present review is to examine how effective current influenza-vaccine strategies are in aged adults, by analysing which are the most important factors modulating the interpretation of study results in this population. Furthermore, consideration will be given to how immune factors influence the measurement of vaccine efficacy/effectiveness, where advancing age leads to deleterious changes in the adaptive immune system, resulting in less than optimal responses to infectious agents and vaccination. Finally this review concludes with possible strategies to improve the ability of the senescent immune system to respond to vaccination.

Antimicrobial prescribing in European nursing homes

OBJECTIVES

The aim of this study was to investigate antimicrobial prescribing in nursing homes in countries across Europe.

METHODS

Point prevalence studies were completed in April and November 2009 in 85 nursing homes in 15 European countries and two UK administrations.

RESULTS

A total of 10,388 and 9430 residents participated in April and November 2009, respectively. The mean prevalence of antimicrobial prescribing in the nursing homes was 6.5% in April and 5.0% in November. The most commonly prescribed antimicrobials were methenamine (17.5%), trimethoprim (11.4%) and co-amoxiclav (11.1%) in April and co-amoxiclav (12.2%), nitrofurantoin (12.2%) and methenamine (11.5%) in November. There was large variation in the overall mean antimicrobial prescribing in the selected nursing homes from each of the contributing countries, ranging from 1.4% in Germany and Latvia to 19.4% in Northern Ireland in April and 1.2% in Latvia to 13.4% in Finland in November. Furthermore, differences in prescribing were apparent within countries with the largest variation evident in nursing homes in Northern Ireland (21.5%) in April and Finland in November (30.1%).

CONCLUSIONS

This is the first study to investigate antimicrobial prescribing in nursing homes in a large number of European countries. The findings suggest that there is considerable variation in antimicrobial prescribing in nursing homes across and within European countries. Nursing homes provide a significant service to the European community and must be supported in order to optimize antimicrobial use and limit the development of antimicrobial resistance.

Host, pathogen and treatment-related prognostic factors in rickettsioses

Diseases caused by rickettsiae, which are vector-borne bacteria, vary widely from mild and self-limiting, to severe and life-threatening. Factors influencing this diversity of outcome are related to the host, to the infectious agent and to the treatment used to treat the infection. A literature search was conducted on PubMed using the phrases "factors-related severity, outcome, host, pathogen, Rickettsia conorii, R. rickettsii, R. africae, R. felis, R. prowazekii, R. typhi, genomics". Among host factors, old age and the male gender have been associated with poor outcome in rickettsioses. Co-morbidities, ethnical factors and the genetic background of the host also seem to influence the outcome of rickettsial diseases. Moreover, although the degree of the host response is beneficial, it could also partly explain the severity observed in some patients. Among pathogen-related factors, traditional concepts of factors of virulence had been challenged and genomic reductive evolution with loss of regulatory genes is the main hypothesis to explain virulence observed in some species, such as Rickettsia prowazekii, the agent of epidemic typhus. R. prowazekii is the more pathogenic rickettsiae and harbours the smaller genome size (1.1 Mb) compared to less or non-virulent species, and is not intracellularly motile, a factor considered as a virulence factor for other intracellular bacteria. The antibiotic regimen used to treat rickettsioses also has an influence on prognosis. Usual concepts of severity and virulence in rickettsioses are challenging and are frequently paradoxical. In this mini-review, we will describe factors currently thought to influence the outcome of the main rickettsioses responsible for illness in humans.

Comparative study of immune status to infectious agents in elderly patients with multiple myeloma, Waldenstrom's macroglobulinemia, and monoclonal gammopathy of undetermined significance

Whereas patients with multiple myeloma (MM) have a well-documented susceptibility to infections, this has been less studied in other B-cell disorders, such as Waldenstrom's macroglobulinemia (WM) and monoclonal gammopathy of undetermined significance (MGUS). We investigated the humoral immunity to 24 different pathogens in elderly patients with MM (n = 25), WM (n = 16), and MGUS (n = 18) and in age-matched controls (n = 20). Antibody titers against pneumococci, staphylococcal alpha-toxin, tetanus and diphtheria toxoids, and varicella, mumps, and rubella viruses were most depressed in MM patients, next to lowest in WM and MGUS patients, and highest in the controls. In contrast, levels of antibodies specific for staphylococcal teichoic acid, Moraxella catarrhalis, candida, aspergillus, and measles virus were similarly decreased in MM and MGUS patients. Comparable titers in all study groups were seen against Haemophilus influenzae type b (Hib), borrelia, toxoplasma, and members of the herpesvirus family. Finally, a uniform lack of antibodies was noted against Streptococcus pyogenes, salmonella, yersinia, brucella, francisella, and herpes simplex virus type 2. To conclude, although MM patients displayed the most depressed humoral immunity, significantly decreased antibody levels were also evident in patients with WM and MGUS, particularly against Staphylococcus aureus, pneumococci, and varicella. Conversely, immunity was retained for Hib and certain herpesviruses in all study groups.

Acquired bloodstream infection in the intensive care unit: incidence and attributable mortality

INTRODUCTION

To estimate the incidence of intensive care unit (ICU)-acquired bloodstream infection (BSI) and its independent effect on hospital mortality.

METHODS

We retrospectively studied acquisition of BSI during admissions of >72 hours to adult ICUs from two university-affiliated hospitals. We obtained demographics, illness severity and co-morbidity data from ICU databases and microbiological diagnoses from departmental electronic records. We assessed survival at hospital discharge or at 90 days if still hospitalized.

RESULTS

We identified 6339 ICU admissions, 330 of which were complicated by BSI (5.2%). Median time to first positive culture was 7 days (IQR 5-12). Overall mortality was 23.5%, 41.2% in patients with BSI and 22.5% in those without. Patients who developed BSI had higher illness severity at ICU admission (median APACHE III score: 79 vs. 68, P < 0.001). After controlling for illness severity and baseline demographics by Cox proportional-hazard model, BSI remained independently associated with risk of death (hazard ratio from diagnosis 2.89; 95% confidence interval 2.41-3.46; P < 0.001). However, only 5% of the deaths in this model could be attributed to acquired-BSI, equivalent to an absolute decrease in survival of 1% of the total population. When analyzed by microbiological classification, Candida, Staphylococcus aureus and gram-negative bacilli infections were independently associated with increased risk of death. In a sub-group analysis intravascular catheter associated BSI remained associated with significant risk of death (hazard ratio 2.64; 95% confidence interval 1.44-4.83; P = 0.002).

CONCLUSIONS

ICU-acquired BSI is associated with greater in-hospital mortality, but complicates only 5% of ICU admissions and its absolute effect on population mortality is limited. These findings have implications for the design and interpretation of clinical trials.

Aging of the human metaorganism: the microbial counterpart

Human beings have been recently reviewed as 'metaorganisms' as a result of a close symbiotic relationship with the intestinal microbiota. This assumption imposes a more holistic view of the ageing process where dynamics of the interaction between environment, intestinal microbiota and host must be taken into consideration. Age-related physiological changes in the gastrointestinal tract, as well as modification in lifestyle, nutritional behaviour, and functionality of the host immune system, inevitably affect the gut microbial ecosystem. Here we review the current knowledge of the changes occurring in the gut microbiota of old people, especially in the light of the most recent applications of the modern molecular characterisation techniques. The hypothetical involvement of the age-related gut microbiota unbalances in the inflamm-aging, and immunosenescence processes will also be discussed. Increasing evidence of the importance of the gut microbiota homeostasis for the host health has led to the consideration of medical/nutritional applications of this knowledge through the development of probiotic and prebiotic preparations specific for the aged population. The results of the few intervention trials reporting the use of pro/prebiotics in clinical conditions typical of the elderly will be critically reviewed.

Inactivated influenza vaccines: recent progress and implications for the elderly

The current public health strategy for the containment of influenza is annual vaccination, which is recommended for the elderly and for those in risk factor categories that present the highest morbidity and mortality. However, because the immune response in the elderly is known to be less vigorous than in younger adults, research in the last decade has focused on improving the immune response to vaccination and increasing the protection of aged populations. The decreased efficacy of vaccines in the elderly is due to several factors, such as a decrease in the number of Langerhans cells, the limited capacity of dendritic cells to present antigen, defects in the expression of Toll-like receptors and the reduced expression of MHC class I and II molecules. Also, production of mature naive T cells by the thymus decreases with age. Among several approaches proposed to address the need for more immunogenic vaccines compared with conventional agents, the most well proven is the use of adjuvants. The first licensed adjuvant, aluminium-based mineral salts (alum), introduced in the 1920s, remains the standard worldwide adjuvant for human use and it has been widely used for almost a century. However, the addition of alum adjuvant to a split or subunit influenza vaccine has induced only marginal improvements. Other adjuvants have been developed and approved for human use since 1997; in particular, MF59, an oil-in-water adjuvant emulsion of squalene, which is able to increase immunogenicity of seasonal, pre-pandemic and pandemic subunit vaccines while maintaining acceptable safety and tolerability profiles. More recently, another oil-in-water emulsion, AS03, has been approved as a component of pre-pandemic H5N1 and pandemic H1N1 2009 vaccines. Besides adjuvants, several other strategies have been assessed to enhance antibody response in the elderly and other less responsive subjects, such as high-dose antigen vaccines, carrier systems (liposomes/virosomes) and the intradermal route of immunization. In particular, the potential of intradermal vaccination is well documented and the recent availability of an appropriate injection system, which combines simplicity, safety and ease of use, has allowed evaluation of the tolerability, safety and immunogenicity of the intradermal influenza vaccine in large numbers of subjects. Data that emerged from large clinical trials showed an improved immunogenicity compared with that of standard vaccine. Observational studies or comparisons between adjuvanted, intradermal or high-dose versus conventional vaccines are needed to evaluate whether the greater immunogenicity observed in a number of recent studies is correlated with greater protection against influenza and influenza-related complications and death.

Aging and HIV infection

INTRODUCTION

Population aging has become a global phenomenon, and HIV infection among older individuals is also increasing. Because age can affect the progression of HIV infection, we aimed to evaluate the present knowledge on HIV infection in older patients.

METHODS

Literature review of the last 20 years.

RESULTS

Older HIV-infected patients have lower CD4(+) T cell counts, higher viral load and are more frequently symptomatic at diagnosis. The infection progresses more rapidly, with higher morbidity and lethality rates. However, older patients are more compliant to antiretroviral treatment; they experience a better virologic response, and treatment represents a positive clinical impact. Aging affects the complex interaction between HIV infection and the immune system. Both conditions contribute to the dysfunction of immune cells, including a decrease in the phagocytes' microbicidal capability, natural killer cells' cytolytic function, expression of toll-like receptors and production of interleukin-12. Chronic immune activation responsible for the depletion of CD4(+) and CD8(+) T cells in HIV infection appears to worsen with senescence. Older patients also exhibit a less robust humoral response, with the production of less avid and specific antibodies.

CONCLUSION

Both HIV and aging contribute to immune dysfunction, morbidity and mortality. However, highly active antiretroviral therapy (HAART) is beneficial for older patients, and treatment of older patients should not be discouraged.

Respiratory disease and the role of oral bacteria

The relationship between oral health and systemic conditions, including the association between poor oral hygiene, periodontal disease, and respiratory disease, has been increasingly debated over recent decades. A considerable number of hypotheses have sought to explain the possible role of oral bacteria in the pathogenesis of respiratory diseases, and some clinical and epidemiological studies have found results favoring such an association. This review discusses the effect of oral bacteria on respiratory disease, briefly introduces the putative biological mechanisms involved, and the main factors that could contribute to this relationship. It also describes the role of oral care for individuals who are vulnerable to respiratory infections.