Bloodstream infections in the elderly

Healthcare-Associated Infections: The Role of Microbial and Environmental Factors in Infection Control-A Narrative Review

Healthcare-associated infections (HAIs), previously known as nosocomial infections, represent a significant threat to healthcare systems worldwide, prolonging patient hospital stays and the duration of antimicrobial therapy. One of the most serious consequences of HAIs is the increase in the rate of antibiotic resistance (AR) generated by the prolonged, frequent, and sometimes incorrect use of antibiotics, which leads to the selection of resistant bacteria, making treatment difficult and expensive, with direct consequences for the safety of patients and healthcare personnel. Therefore, timely and accurate diagnosis of HAIs is mandatory to develop appropriate infection prevention and control practices (IPC) and new therapeutic strategies. This review aimed to present the prevalence, risk factors, current diagnosis, including artificial intelligence (AI) and machine learning approaches, future perspectives in combating HAIs causative bacteria (phage therapy, microbiome-based interventions, and vaccination), and HAIs surveillance strategies. Also, we discussed the latest findings regarding the relationships of AR with climate change and environmental pollution in the context of the One Health approach. Phage therapy is an emerging option that can offer an alternative to ineffective antibiotic treatments for antibiotic-resistant bacteria causing HAIs. Clinical trials dealing with vaccine development for resistant bacteria have yielded conflicting results. Two promising strategies, fecal microbiota transplantation and probiotic therapy, proved highly effective against recurrent Clostridium difficile infections and have been shown to reduce HAI incidence in hospitalized patients undergoing antibiotic therapy. Artificial intelligence and machine learning systems offer promising predictive capabilities in processing large volumes of clinical, microbiological, and patient data but require robust data integration. Our paper argues that HAIs are still a global challenge, requiring stringent IPC policies, computer vision, and AI-powered tools. Despite promising avenues like integrated One Health approaches, optimized phage therapy, microbiome-based interventions, and targeted vaccine development, several knowledge gaps in clinical efficacy, standardization, and pathogen complexity remain to be answered.

Blood-Stream Infections: Causative Agents, Antibiotic Resistance and Associated Factors in Older Patients

Background

The rate of multi-drug antibiotic resistance in nosocomial bloodstream infections in elderly patients is increasing. This study examined the data for bloodstream infections to gain a better understanding of bacterial antibiotic resistance.

Methods

This was a retrospective study of 817 patients with the first positive blood culture between January 1, 2016 and December 31, 2019.

Results

Moyen's age was 77.4 ± 9.8 years, male (52.4%) and SOFA 5.0 ± 4. ESBL(+) rate was 78/817 (9.5%). ESBL(+) rate for Escherichia coli and Klebsiella pneumoniae was 69/141 (48.9%) and 9/52 (17.3%), respectively. The most common isolates were Escherichia coli (17.3%), Stenotrophomonas maltophilia (13.7%), and Staphylococcus species (23.1%). The rate of septic shock and mortality accounted for 22.3% and 28.9%, respectively. Escherichia coli is highly sensitive to carbapenem, and resistant (>50%) with quinolone and aminoside. Klebsiella pneumoniae and Pseudomonas aeruginosa were highly sensitive to carbapenem. Acinetobacter baumannii was resistant to meropenem (75%). Stenotrophomonas maltophilia was sensitive to quinolone (13.8 %), and highly resistant to remaining antibiotics. Methicillin-resistant Staphylococcus aureus had a low resistance rate for vancomycin, teicoplanin, and linezolid. Multivariate analysis showed that the significant factors associated with mortality were age >75; SOFA >7; respiratory infection; intensive care unit treatment and presentation with septic shock.

Conclusion

The mortality rate was still high, especially for antibiotic-resistant agents.

Dementia, stroke, age, use of medical devices and antipsychotic drugs may increase the risk of nosocomial infections among elderly patients hospitalized at Neurology Clinics

Healthcare-acquired infections (HCAI) represent a major health problem worldwide. Stroke and dementia are considered risk factors for HCAI. Preliminary data suggest that use of antipsychotic drugs also increase the risk for HCAI. Here, we performed a retrospective study aimed at investigating the major risk and protective factors for HCAI in a cohort of elderly subjects hospitalized at an Italian tertiary Neurology Clinics. We included all patients with age ≥ 65 years hospitalized at Neurology Clinics of National Institute on Ageing, Ancona, Italy from 1st January 2018 to 31st December 2021. For each patient, the following data were collected: age, sex, use of medical devices, comorbidities, use of antipsychotic medications, development of HCAI. We included 1543 patients (41.4% males; median age 85 years [80-89]). According to multivariable analysis, age, stroke, duration of urinary catheter placement (for all p < 0.001) and midline placement (p = 0.035) resulted to be risk factors for HCAI, Diabetes resulted to be a protective factor for pneumonia (p = 0.041), while dementia and nasogastric tube were risks factor for this condition (p = 0.022 and p < 0.001, respectively). Urinary catheter was a risk factor for urinary tract infections (p < 0.001). Duration of placement of vascular catheters and use of antipsychotic drugs resulted to significantly increase the risk for bloodstream infections. Stroke, age and use of medical devices were confirmed to be risk factors for HCAI. Antipsychotic drugs resulted to increase risk for bloodstream infections. Further prospective studies will be needed to confirm these findings.

Outcomes of octogenarians and nonagenarians with Pseudomonas aeruginosa bacteremia: a multicenter retrospective study

BACKGROUND

P. aeruginosa bacteremia is a common and severe infection carrying high mortality in older adults. We aimed to evaluate outcomes of P. aeruginosa bacteremia among old adults (≥ 80 years).

METHODS

We included the 464/2394 (19%) older adults from a retrospective multinational (9 countries, 25 centers) cohort study of individuals hospitalized with P. aeruginosa bacteremia. Bivariate and multivariable logistic regression models were used to evaluate risk factors for 30-day mortality among older adults.

RESULTS

Among 464 adults aged ≥ 80 years, the mean age was 84.61 (SD 3.98) years, and 274 (59%) were men. Compared to younger patients, ≥ 80 years adults had lower Charlson score; were less likely to have nosocomial acquisition; and more likely to have urinary source. Thirty-day mortality was 30%, versus 27% among patients 65-79 years (n = 894) and 25% among patients < 65 years (n = 1036). Multivariate analysis for predictors of mortality among patients ≥ 80 years, demonstrated higher SOFA score (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.23-1.51, p < 0.001), corticosteroid therapy (OR 3.15, 95% CI: 1.24-8.01, p = 0.016) and hospital acquired P. aeruginosa bacteremia (OR 2.30, 95% CI: 1.33-3.98, p = 0.003) as predictors. Appropriate empirical therapy within 24 h, type of definitive anti-pseudomonal drug, and type of regimen (monotherapy or combination) were not associated with 30-day mortality.

CONCLUSIONS

In older adults with P. aeruginosa bacteremia, background conditions, place of acquisition, and disease severity are associated with mortality, rather than the antimicrobial regimen. In this regard, preventive efforts and early diagnosis before organ failure develops might be beneficial for improving outcomes.

Effects of Inappropriate Administration of Empirical Antibiotics on Mortality in Adults With Bacteraemia: Systematic Review and Meta-Analysis

Introduction

Bloodstream infections are associated with high mortality rates and contribute substantially to healthcare costs, but a consensus on the prognostic benefits of appropriate empirical antimicrobial therapy (EAT) for bacteraemia is lacking.

Methods

We performed a systematic search of the PubMed, Cochrane Library, and Embase databases through July 2021. Studies comparing the mortality rates of patients receiving appropriate and inappropriate EAT were considered eligible. The quality of the included studies was assessed using Joanna Briggs Institute checklists.

Results

We ultimately assessed 198 studies of 89,962 total patients. The pooled odds ratio (OR) for the prognostic impacts of inappropriate EAT was 2.06 (P < 0.001), and the funnel plot was symmetrically distributed. Among subgroups without between-study heterogeneity (I² = 0%), those of patients with severe sepsis and septic shock (OR, 2.14), Pitt bacteraemia scores of ≥4 (OR, 1.88), cirrhosis (OR, 2.56), older age (OR, 1.78), and community-onset/acquired Enterobacteriaceae bacteraemia infection (OR, 2.53) indicated a significant effect of inappropriate EAT on mortality. The pooled adjusted OR of 125 studies using multivariable analyses for the effects of inappropriate EAT on mortality was 2.02 (P < 0.001), and the subgroups with low heterogeneity (I² < 25%) exhibiting significant effects of inappropriate EAT were those of patients with vascular catheter infections (adjusted OR, 2.40), pneumonia (adjusted OR, 2.72), or Enterobacteriaceae bacteraemia (adjusted OR, 4.35). Notably, the pooled univariable and multivariable analyses were consistent in revealing the negligible impacts of inappropriate EAT on the subgroups of patients with urinary tract infections and Enterobacter bacteraemia.

Conclusion

Although the current evidence is insufficient to demonstrate the benefits of prompt EAT in specific bacteraemic populations, we indicated that inappropriate EAT is associated with unfavorable mortality outcomes overall and in numerous subgroups. Prospective studies designed to test these specific populations are needed to ensure reliable conclusions.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021270274.

Gram-negative endocarditis: disease presentation, diagnosis and treatment

PURPOSE OF REVIEW

Gram-negative bacilli (GNB) cause between 1% and 10% of infective endocarditis (IE). Most episodes are caused by microorganisms of the Haemophilus spp., Aggregatibacter spp. Cardiobacterium spp., Eikenella spp., and Kingella spp (HACEK) group. The frequency of IE caused by non-HACEK (GNB-IE) has increased in recent years. Uncertainties persist regarding its best medical treatment and the appropriateness and timing of surgical treatment. In addition, there are new drugs with activity against multiresistant microorganisms, of which there is little experience in this disease. We review this topic by answering the most frequently asked questions that arise among our colleagues.

RECENT FINDINGS

HACEK microorganisms cause 1.5-2% of IE with only a 2% mortality. In contrast, non-HACEK GNB-IE accounts for 2.5-3% of all IE cases and is associated with nosocomial acquisition, advanced age, solid organ transplantation and 20-30% mortality. Drug addiction is important in areas with epidemic opioid abuse.

SUMMARY

The frequency of IE caused by GNB has been modified in recent years. HACEK episodes are no longer treated with ampicillin and aminoglycosides. In non-HACEK GNB-IE, combination therapy with a beta-lactam and a quinolone or aminoglycoside is recommended. The surgical indication and its value are evident in many patients. Management should rely on a collaborative group with experience in this disease.

Admissions and Mortality Related to Urinary Tract Infections in Male Veterans with Dementia

Objective To examine mortality and hospital readmission rates in male veterans with dementia diagnosed with urinary tract infection (UTI) compared with patients without dementia. Design Retrospective cohort study. Setting Veterans Healthcare Systems (VA). Participants Male inpatients with a diagnosis of UTI who were treated at any VA Healthcare Center from January 1, 2009, to December 31, 2018. Interventions None. Main Outcome Measures Mortality and hospital readmission for patients with and without dementia at 30, 60, and 90 days from UTI diagnosis. Results 262,515 veterans admitted with UTI were analyzed, and 58,940 (22.5%) had dementia. The mean age for veterans with dementia was 80.0 +/- 9.7 years. Veterans with dementia experienced less mortality than patients without dementia at 30 days (8.3% vs 8.5%; P < 0.001), but more mortality at 60-day (4.9% vs 4.7%; P < 0.001) and 90-day (3.6% vs 3.3%; P < 0.001) intervals. Death was 20% less likely at 30 days in patients with dementia. Veterans with dementia were readmitted more than those without dementia at 30-day (18.4% vs 16.0%), 60-day (4.5% vs 2.8%), and 90-day (3.4% vs 2.5%) intervals; P < 0.0001. Conclusion Though patients with dementia are at an increased risk for death long-term, risk of death is less than those without dementia shortly following UTI diagnosis. This highlights the possibility that veterans with dementia may be hospitalized and diagnosed with UTIs when in actuality they have asymptomatic bacteriuria. Patients with dementia and UTI therefore represent an important group of geriatric patients that could benefit from the oversight of a senior care pharmacist to help prevent unnecessary treatment of asymptomatic bacteriuria.

Bloodstream infections in the elderly: what is the real goal?

Bloodstream infections (BSI) represent a serious bacterial infection with substantial morbidity and mortality. Population-based studies demonstrate an increased incidence, especially among elderly patients. Controversy exists regarding whether presentation of BSI are different in older patients compared to younger patients; our narrative review of the literature suggests that BSI in elderly patients would probably include one or more of the traditional symptoms/signs of fever, severe sepsis or septic shock, acute kidney injury, and/or leukocytosis. Sources of BSI in older adults are most commonly the urinary tract (more so than in younger adults) and the respiratory tract. Gram-negative bacteria are the most common isolates in the old (~ 40-60% of BSI); isolates from the elderly patient population show higher antibiotic resistance rates, with long-term care facilities serving as reservoirs for multidrug-resistant bacteria. BSI entail significantly higher rates of mortality in older age, both short and long term. Some of the risk factors for mortality are modifiable, such as the appropriateness of empirical antibiotic therapy and nosocomial acquisition of infection. Health-related quality of life issues regarding the elderly patient with BSI are not well addressed in the literature. Utilization of comprehensive geriatric assessment and comprehensive geriatric discharge planning need to be investigated further in this setting and might serve as key for improved results in this population. In this review, we address all these aspects of BSI in old patients with emphasis on future goals for management and research.

Added value of clinical prediction rules for bacteremia in hemodialysis patients: An external validation study

Introduction

Having developed a clinical prediction rule (CPR) for bacteremia among hemodialysis (HD) outpatients (BAC-HD score), we performed external validation.

Materials & methods

Data were collected on maintenance HD patients at two Japanese tertiary-care hospitals from January 2013 to December 2015. We enrolled 429 consecutive patients (aged ≥ 18 y) on maintenance HD who had had two sets of blood cultures drawn on admission to assess for bacteremia. We validated the predictive ability of the CPR using two validation cohorts. Index tests were the BAC-HD score and a CPR developed by Shapiro et al. The outcome was bacteremia, based on the results of the admission blood cultures. For added value, we also measured changes in the area under the receiver operating characteristic curve (AUC) using logistic regression and Net Reclassification Improvement (NRI), in which each CPR was added to the basic model.

Results

In Validation cohort 1 (360 subjects), compared to a Model 1 (Basic Model) AUC of 0.69 (95% confidence interval [95% CI]: 0.59–0.80), the AUC of Model 2 (Basic model + BAC-HD score) and Model 3 (Basic model + Shapiro’s score) increased to 0.8 (95% CI: 0.71–0.88) and 0.73 (95% CI: 0.63–0.83), respectively. In validation cohort 2 (96 subjects), compared to a Model 1 AUC of 0.81 (95% CI: 0.68–0.94), the AUCs of Model 2 and Model 3 increased to 0.83 (95% CI: 0.72–0.95) and 0.85 (95% CI: 0.76–0.94), respectively. NRIs on addition of the BAC-HD score and Shapiro’s score were 0.3 and 0.06 in Validation cohort 1, and 0.27 and 0.13, respectively, in Validation cohort 2.

Conclusion

Either the BAC-HD score or Shapiro’s score may improve the ability to diagnose bacteremia in HD patients. Reclassification was better with the BAC-HD score.

Reliability of nonlocalizing signs and symptoms as indicators of the presence of infection in nursing-home residents

Antibiotics are among the most common medications prescribed in nursing homes. The annual prevalence of antibiotic use in residents of nursing homes ranges from 47% to 79%, and more than half of antibiotic courses initiated in nursing-home settings are unnecessary or prescribed inappropriately (wrong drug, dose, or duration). Inappropriate antibiotic use is associated with a variety of negative consequences including Clostridioides difficile infection (CDI), adverse drug effects, drug-drug interactions, and antimicrobial resistance. In response to this problem, public health authorities have called for efforts to improve the quality of antibiotic prescribing in nursing homes.

A prospective study of epidemiology characteristics and outcomes of bloodstream infections in older patients

OBJECTIVE

This study aimed to investigate the characteristics of bloodstream infections (BSIs) in older patients and describe the differences between community-acquired, hospital-acquired and health care-associated BSIs.

METHODS

A prospective observational study was conducted at the University Hospital of Heraklion, Crete, Greece. Epidemiology, clinical characteristics and outcomes of BSIs were recorded.

RESULTS

During a four-year period, 113 BSIs were recorded. Of them, 42% occurred in male patients; patients' mean age was 80 years. BSIs were community-acquired in 76% of patients, hospital-acquired in 12% and health care-associated in 12%. The most commonly isolated bacteria were E coli and K pneumoniae. Thirty-day mortality from detection of BSIs was 27%. Patients with fever, without septic shock and with appropriate empirical treatment were less likely to die.

CONCLUSION

Community-acquired, health care-associated and hospital-acquired BSIs had different presentation, microbiology and outcomes. Older patients had a high mortality. The absence of fever, inappropriate empirical treatment and septic shock were independent mortality predictors.

Impact of Perioperative Urinary Tract Infection on Surgical Site Infection in Patients Undergoing Primary Hip and Knee Arthroplasty

BACKGROUND

The literature lacks clear consensus regarding the association between postoperative urinary tract infection (UTI) and surgical site infection (SSI). Additionally, in contrast to preoperative asymptomatic bacteriuria, SSI risk in patients with preoperative UTI has been incompletely studied. Therefore, our goal was to determine the effect of perioperative UTI on SSI in patients undergoing primary hip and knee arthroplasty.

METHODS

Using the National Surgical Quality Improvement Program database, all patients undergoing primary hip and knee arthroplasty were identified. Univariate and multivariate regressions, as well as propensity matching, were used to determine the independent risk of preoperative and postoperative UTI on SSI, reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Postoperative UTI significantly increased the risk for superficial wound infection (OR 2.147, 95% CI 1.622-2.842), deep periprosthetic joint infection (PJI) (OR 2.288, 95% CI 1.579-3.316), and all SSIs (superficial and deep) (OR 2.193, 95% CI 1.741-2.763) (all P < .001). Preoperative UTI was not associated with a significantly increased risk of superficial infection (P = .636), PJI (P = .330), or all SSIs (P = .284). Further analysis of UTI present at the time of surgery using propensity matching showed no increased risk of superficial infection (P = 1.000), PJI (P = .624), or SSI (P = .546).

CONCLUSION

Postoperative UTI was associated with SSI, reinforcing the need to minimize factors which predispose patients to the risk of UTI after surgery. The lack of association between preoperative UTI and SSI suggests that hip and knee arthroplasty can proceed without delay, although initiating antibiotic treatment is prudent and future prospective investigations are warranted.

Is brain imaging necessary for febrile elderly patients with altered mental status? A retrospective multicenter study

OBJECTIVE

Altered mental status (AMS) is one of the most common symptoms in the febrile elderly. Brain imaging tests are an important tool for diagnosing AMS patients. However, these may be prescribed unnecessarily in emergency departments, particularly for febrile patients with AMS for whom infection is suspected, leading to excessive radiation risk and cost. In this study, we investigated the factors that can predict clinically significant abnormal brain imaging (ABI) in the febrile elderly with AMS.

METHODS

This retrospective multicenter study was conducted from July 2016 to June 2019. Febrile patients over the age of 65 years with AMS who visited the emergency department of two tertiary university hospitals were enrolled. Medical records were reviewed, and laboratory results were obtained. Brain imaging results with a formal reading by a radiologist were obtained.

RESULTS

In all, 285 patients were enrolled, and 47 (16.49%) showed ABI. The most common diagnoses in patients admitted to the emergency department were intracranial hemorrhage and ischemic stroke for ABI, and pneumonia and urinary tract infection for non-ABI. In multivariate logistic regression analyses, higher systolic blood pressure (odds ratio [OR], 1.017; 95% confidence interval [CI], 1.006-1.028), lower body temperature (OR, 0.578; 95% CI, 0.375-0.892), the presence of lateralizing sign (OR, 45.676; 95% CI, 5.015-416.025), and lower Glasgow Coma Scale (OR, 0.718; 95% CI, 0.617-0.837) were significantly associated with ABI.

CONCLUSION

Lower Glasgow Coma Scale, the presence of lateralizing sign, higher systolic blood pressure, and lower body temperature are significantly associated with ABI in febrile elderly patients with AMS.

Development and validation of a screening tool for early identification of bloodstream infection in older patients - a retrospective case-control study

BACKGROUND

Delayed diagnosis of bloodstream infection (BSI) occurs in > 20% of older patients, with misdiagnosis in 35%. Our objective was to develop and validate a clinically useful screening tool to identify older patients with a high probability of having a BSI.

METHODS

Hospitalized patients > 80 years old with BSI (n = 105/group) were evaluated for the tool development in this retrospective matched case-controlled study (learn cohort). The tool was validated in different retrospectively matched case and control patients > 80 years old (n = 120/group) and 65 to 79 years old (n = 250/group) (test cohort). Binary logistic regression was used to develop a screening tool using laboratory and clinical parameters that were significantly associated with BSI (P < 0.05; adjusted odds ratio (OR) > 1); and Classification and Regression Tree (CART) analysis was used to identify parameter breakpoints. Performance metrics were used to evaluate and validate the tool.

RESULTS

The significant parameters associated with BSI were maximum temperature (Tmax)(> 37.55C)(OR = 42.575), neutrophils (> 7.95)(OR = 1.923), a change in level of consciousness (LOC) (Yes = 1, No = 0)(OR = 1.571), blood urea nitrogen (BUN)(> 10.05)(OR = 1.359), glucose (> 7.35)(OR = 1.167), albumin (< 33.5)(OR = 1.038) and alanine aminotransferase (ALT) (> 19.5)(OR = 1.005). The optimal screening tool [Ln (odds of BSI) = - 150.299 + 3.751(Tmax) + 0.654(neutrophils) + 0.452(change in LOC) + 0.307(BUN) + 0.154(glucose) + 0.038(albumin) + 0.005(ALT)] had favorable performance metrics in the learn and test cohorts (sensitivity, specificity and accuracy of 95% in the learn cohort and 77, 89, and 81% in the total test cohort); and performed better than using only temperature and neutrophil count.

CONCLUSIONS

The validated tool had high predictive value which may improve early identification and management of BSI in older patients.

Geriatric urinary tract infections: The value of laboratory parameters in estimating the need for bacteremia and Intensive Care Unit

Objective:

We investigated the geriatric patients diagnosed as urinary tract infection and evaluated the effects of white blood cell (WBC), neutrophil count, platelet, mean platelet volume (MPV), red cell distribution width (RDW), total bilirubin, direct bilirubin, creatine, albumin, erythrocyte sedimentation rate, C-reactive protein, and neutrophil/lymphocyte ratio parameters on estimating the need for bacteremia and intensive care (IC) for the patients with pyelonephritis

Methods:

Between 2016-2017, a total number of 188 patients aged 65 years and above were retrospectively evaluated at the infectious diseases clinic.

Results:

The 124 (66%) of the patients were male and 64 (34%) were female. The laboratory values of the patients with pyelonephritis and urosepsis were found to be significantly lower in only RDW bacteremic patients (p=0.047). The laboratory values during the application of third-step IC unit patients, who were treated and discharged, were compared. Albumin was significantly lower, while direct bilirubin, AST and ALT were significantly higher (p<0.05).

Conclusions:

Patients, whose biochemical parameters have changed, especially during admission or follow-up, should be evaluated carefully in terms of urosepsis, multiple organ failure and IC need. A number of diagnostic tests have been described to predict the need for sepsis and IC. However, many of them cannot be performed in emergency conditions. It is a great advantage that the parameters we use in our work are easily accessible and can be performed in emergency conditions.

Risk Factors and Outcomes of Endocarditis Due to Non-HACEK Gram-Negative Bacilli: Data from the Prospective Multicenter Italian Endocarditis Study Cohort

The objective of this study was to investigate predisposing factors and outcomes of infective endocarditis (IE) caused by non-HACEK Gram-negative bacilli (GNB) in a contemporary multicenter cohort. Patients with IE due to GNB, prospectively observed in 26 Italian centers from 2004 to 2011, were analyzed. Using a case-control design, each case was compared to three age- and sex-matched controls with IE due to other etiologies. Logistic regression was performed to identify risk factors for IE due to GNB. Factors associated with early and late mortality were assessed by Cox regression analysis. The study group comprised 58 patients with IE due to GNB. We found that Escherichia coli was the most common pathogen, followed by Pseudomonas aeruginosa and Klebsiella pneumoniae The genitourinary tract as a source of infection (odds ratio [OR], 13.59; 95% confidence interval [CI], 4.63 to 39.93; P < 0.001), immunosuppression (OR, 5.16; 95% CI, 1.60 to 16.24; P = 0.006), and the presence of a cardiac implantable electronic device (CIED) (OR, 3.57; 95% CI, 1.55 to 8.20; P = 0.003) were factors independently associated with IE due to GNB. In-hospital mortality was 13.8%, and mortality rose to 30.6% at 1 year. A multidrug-resistant (MDR) etiology was associated with in-hospital mortality (hazard ratio [HR], 21.849; 95% CI, 2.672 to 178.683; P = 0.004) and 1-year mortality (HR, 4.408; 95% CI, 1.581 to 12.287; P = 0.005). We conclude that the presence of a genitourinary focus, immunosuppressive therapy, and an indwelling CIED are factors associated with IE due to GNB. MDR etiology is the major determinant of in-hospital and long-term mortality.

Urinary tract infections in the geriatric patients

OBJECTIVE

Urinary tract infections (UTI) are the second most common infection in geriatric population. This study investigated clinical findings, diagnostic approaches, complicating factors, prognosis, causative microorganisms and antimicrobial susceptibility in geriatric patients diagnosed with UTI.

METHODS

A total of 140 hospitalised patients with UTIs were evaluated within three years between January 2011-January 2015 at the Eskisehir Yunus Emre State Hospital. UTI diagnosed when there were systemic and urinary signs and symptoms and a positive dipstick test and urine culture result, leukocyte and CRP like serum parameters.

RESULTS

Among the studied patients, 41.4% had urological diseases, 20.7% had diabetes mellitus and 19.2% had neurological diseases. The most common symptoms and signs were fever, dysuria nausea/vomiting, general condition impairment, pyuria, haematuria. The laboratory values for CRP, ESR and leukocyte count were 84 mg/dL, 56 mm/s and 11.9 (10^3μL), with mean values being determined. Among patients having a urinary catheter (17.1%), 27.9% had a history of UTI, while 29.3% had been hospitalised. Escherichia coli and Klebsiella pneumoniae were the most commonly identified microorganisms. The mean duration for hospitalisation was 7.6 days, while a 5% mortality rate was observed over the course of the disease.

CONCLUSION

Because of the potential for serious complications and mortality, elderly patients with urinary tract infection, should receive immediate empirical treatment based on anamnesis, clinical evaluation and urinalysis and should be re-examined using results from cultures and antibiograms upon follow-up.

Development and Validation of a Clinical Prediction Rule for Bacteremia among Maintenance Hemodialysis Patients in Outpatient Settings

Background

To our knowledge, no reliable clinical prediction rule (CPR) for identifying bacteremia in hemodialysis (HD) patients has been established. The aim of this study was to develop a CPR for bacteremia in maintenance HD patients visiting the outpatient department.

Methods

This multicenter cohort study involved consecutive maintenance HD patients who visited the outpatient clinic or emergency room of seven Japanese institutions between August 2011 and July 2013. The outcome measure was bacteremia diagnosed based on the results of blood cultures. The candidate predictors for bacteremia were extracted through a literature review. A CPR for bacteremia was developed using a coefficient-based multivariable logistic regression scoring method, and calibration was performed. The test performance was then assessed for the CPR.

Results

Of 507 patients eligible for the study, we analyzed the 293 with a complete dataset for candidate predictors. Of these 293 patients, 48 (16.4%) were diagnosed with bacteremia. At the conclusion of the deviation process, body temperature ≥ 38.3°C, heart rate ≥ 125 /min, C-reactive protein ≥ 10 mg/dL, alkaline phosphatase >360 IU/L, and no prior antibiotics use within the past week were retained and scored. The CPR had a good fit for the model on calibration. The AUC of the CPR was 0.76, and for score CPR ≥ 2, the sensitivity and specificity were 89.6% and 51.4%, respectively.

Conclusions

We established a simple CPR for bacteremia in maintenance HD patients using routinely obtained clinical information in an outpatient setting. This model may facilitate more appropriate clinical decision making.

Comparison of gram-negative and gram-positive hematogenous pyogenic spondylodiscitis: clinical characteristics and outcomes of treatment

Background

To the best of our knowledge, no study has compared gram-negative bacillary hematogenous pyogenic spondylodiscitis (GNB-HPS) with gram-positive coccal hematogenous pyogenic spondylodiscitis (GPC-HPS) regarding their clinical characteristics and outcomes.

Methods

From January 2003 to January 2013, 54 patients who underwent combined antibiotic and surgical therapy in the treatment of hematogenous pyogenic spondylodiscitis were included.

Results

Compared with 37 GPC-HPS patients, the 17 GNB-HPS patients were more often found to be older individuals, a history of cancer, and a previous history of symptomatic urinary tract infection. They also had a less incidence of epidural abscess formation compared with GPC-HPS patients from findings on magnetic resonance imaging (MRI). Constitutional symptoms were the primary reasons for initial physician visits in GNB-HPS patients whereas pain in the affected spinal region was the most common manifestation in GPC-HPS patients at initial visit. The clinical outcomes of GNB-HPS patients under combined surgical and antibiotic treatment were not different from those of GPC-HPS patients. In multivariate analysis, independent predicting risk factors for GNB-HPS included a malignant history and constitutional symptoms and that for GPC-HPS was epidural abscess.

Conclusions

The clinical manifestations and MRI presentations of GNB-HPS were distinguishable from those of GPC-HPS.

Non-nosocomial healthcare-associated left-sided Pseudomonas aeruginosa endocarditis: a case report and literature review

Background

With the development of invasive medical procedures, an increasing number of healthcare-associated infective endocarditis cases have been reported. In particular, non-nosocomial healthcare-associated infective endocarditis in outpatients with recent medical intervention has been increasingly identified.

Case presentation

A 66-year-old man with diabetes mellitus and a recent history of intermittent urethral self-catheterization was admitted due to a high fever. Repeated blood cultures identified Pseudomonas aeruginosa, and transesophageal echocardiography uncovered a new-onset severe aortic regurgitation along with a vegetative valvular structure. The patient underwent emergency aortic valve replacement surgery and was successfully treated with 6 weeks of high-dose meropenem and tobramycin. Historically, most cases of P. aeruginosa endocarditis have occurred in the right side of the heart and in outpatients with a history of intravenous drug abuse. In the case presented, the repeated manipulations of the urethra may have triggered the infection. Our literature review for left-sided P. aeruginosa endocarditis showed that non-nosocomial infection accounted for nearly half of the cases and resulted in fatal outcomes as often as nosocomial cases. A combination therapy with anti-pseudomonal beta-lactams or carbapenems and aminoglycosides may be the preferable treatment. Medical treatment alone may be effective, and surgical treatment should be carefully considered.

Conclusions

We presented a rare case of native aortic valve endocarditis caused by P. aeruginosa. This case illustrates the importance of identifying the causative pathogen(s), especially for outpatients with a recent history of medical procedures.

Risk Factors for Nosocomial Bacteremia in a Large Spanish Teaching Hospital: A Case-Control Study

Objective:

Identify independent risk factors associated with the development of nosocomial bacteremia.

Design:

Exploratory, unmatched, case-control study.

Setting:

A 970-bed Spanish university hospital.

Patients:

All non-neutropenic adult patients with nosocomial bacteremia admitted during a 12-month period were eligible as cases. All adult non-neutropenic patients without nosocomial bacteremia were eligible as controls.

Results:

The incidence of bacteremia in the study population was 6.9/1000 admissions/ year. One hundred eighty cases and 180 controls were analyzed. Multivariate analysis (stepwise logistic regression techniques) identified seven risk factors independently associated with nosocomial bacteremia: age above 65 years; prior admission (within six months) to the hospital; underlying diseases that were ultimately or rapidly fatal; indwelling urethral catheter in place for more than three days; intravenous central lines or peripheral venous lines (if in place for more than four days); “high-risk surgery” (i.e., lower abdominal, cardiac or thoracic); and admission to an intensive care unit.

Conclusions:

Although five variables are not modifiable, the remaining two relate to the use and duration of devices. Our data give strong support for the value of testing strict guidelines for limiting vascular catheters and evaluating the need for prolonged urethral catheterization. If effective infection control measures are identified, we could target hospital-wide surveillance to patients whose risk factors are amenable to intervention.

Risk Factors for Urosepsis in Older Adults: A Systematic Review

Objective: To identify factors that predispose older adults to urosepsis and urosepsis-related mortality. Method: A systematic search using PubMed and CINAHL databases. Articles that met inclusion criteria were assessed using the Strengthening the Reporting of OBservational studies in Epidemiology (STROBE) criteria and were scored on a 4-point Likert-type scale. Results: A total of 180 articles were identified, and six met inclusion criteria. The presence of an internal urinary catheter was associated with the development of urosepsis and septic shock. Although a number of factors were examined, functional dependency, number of comorbidities, and low serum albumin were associated with mortality across multiple studies included in this review. Discussion: Little scientific evidence is available on urosepsis, its associated risk factors, and those factors associated with urosepsis-related mortality in older adults. More research is warranted to better understand urosepsis in this vulnerable population in an effort to improve the quality of patient care.

Bloodstream infections in older patients

Bloodstream infections (BSIs) are both common and fatal in older patients. We describe data from studies evaluating older patients hospitalized with BSIs. Most older patients with BSIs present "typically" with either fever or leukocytosis. The most common source of BSI in older patients is the urinary tract, and accordingly, Gram-negative organisms predominate. A significant part of these BSIs may thus be preventable by removal of unnecessary urinary catheters. Increased long term mortality is reported following BSIs in older patients, however, data on other long-term outcomes, including functional capacity, cognitive decline and others are lacking. Management of BSIs may include less invasive procedures due to the fragility of older patients. This approach may delay the diagnosis and treatment in some cases. Older patients are probably under-represented in clinical trials assessing treatment of bacteremia. Physicians treating older patients should consider the relevance of these studies' outcomes.

Predictive factors of bacteremia in patients with febrile urinary tract infection: an experience at a tertiary care center

PURPOSE

To investigate the clinical features in adult patients with febrile urinary tract infection (UTI) who visited the emergency department (ED) and to determine the predictive factors of bacteremia among the initial presenting clinical features.

METHODS

This retrospective cohort study was conducted at the ED of a tertiary hospital in Korea from 1 January 2012 to 31 December 2012. All adult patients who were diagnosed with febrile UTI and for whom data on blood and urine cultures were available were included in the study. Clinical examinations and laboratory tests were performed at the initial presentation.

RESULTS

A total of the 325 patients with febrile UTI (median age: 60 years) were included for analysis, of whom 82 % were female. Bacteremia was detected in 106 of the 325 patients (32.6 %), with Escherichia coli the most frequent pathogen detected (59.7 % of cases). Between the bacteremic and non-bacteremic groups, there was significant difference in age (67 vs. 57 years, respectively), flank pain (16 vs. 7.8 %), suprapubic discomfort (0 vs. 4.6 %), body temperature (38.8 vs. 38.3 °C), respiratory rate (21 vs. 20/min), platelet count (170 vs. 186 × 10(3)/μL), C-reactive protein (10.2 vs. 8.3 mg/dL), and procalcitonin (1.5 vs. 0.3 ng/mL) (P < 0.05 for all). In the multivariate logistic regression analysis, age [odds ratio (OR) 1.03; 95 % confidence interval (CI) 1.01-1.05], systolic blood pressure of <90 mmHg (OR 3.27; 95 % CI 1.13-9.45), body temperature of >39 °C (OR 4.26; 95 % CI 2.28-7.96), and procalcitonin level of >0.5 ng/dL (OR 2.03; 95 % CI 1.07-3.86) were significantly associated with bacteremia.

CONCLUSION

Among our adult patients with febrile UTI, age, systolic blood pressure, body temperature, and procalcitonin were significantly associated with bacteremia. We therefore suggest that these factors should be considered when deciding upon treatment options for febrile UTI patients at the ED.

Risk factors for 28-day mortality in elderly patients with extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae bacteremia

Gram-negative bacteremia is common in elderly patients and, compared with younger patients, mortality rates in bacteremic elderly patients are high. ESBL-producing organisms were one of the most important risk factors associated with mortality. In addition, older age is one of risk factors for colonization or infection with ESBL-producing organisms. We conducted a retrospective cohort study to evaluate risk factors of all-cause 28-day mortality in elderly patients with ESBL-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) bacteremia. Patients aged 65 years or older, who had one or more blood cultures positive for E. coli and K. pneumoniae and who were hospitalized between January 2006 and December 2010 at a tertiary-care teaching hospital, were included. 191 bacteremic elderly patients were eligible for the study. The all-cause 28-day mortality rate was 24.6% (47/191). In multivariate analysis, prior antimicrobial therapy (p=0.014) and an elevated SOFA score (p<0.001) were independent risk factors for increased mortality, while urinary tract infection (UTI) was an independent determinant for non-mortality (p=0.011). In the current study, prior antimicrobial therapy within 30 days, an elevated SOFA score and nonurinary source of infection were significantly associated with adverse outcomes in elderly patients with ESBL-producing gram-negative bacteremia.

[Bloodstream infection in the up to 80 year-old-patients]

INTRODUCTION

The aim of our study was to describe the characteristics of bacteremia detected in patients over 79 years and to identify possible factors associated with the mortality.

METHODS

A retrospective cohort study, which included all patients over 17 years of age with bacteremia detected between 2004-7 was performed. Demographic variables, comorbidities, source of bacteremia, causing microorganism, severity and hospital mortality were recorded. Patients were classified into three age groups: 18 to 64 years (G1), 65 to 79 (G2) and ≥80 years (G3).

RESULTS

We analyzed 1594 episodes of bacteremia (35% in G1, 35% in G2 and 29% in G3). In G3, 47% had renal failure, 83% solid neoplasm, 2% immunosuppression 5% malnutrition and 38% decubitus ulcers. These proportions were 27, 30, 5 and 2%, respectively in G2, and 15, 16, 12 and 5% in G1 (P<.01). The urinary focus accounted for 28%, 43% and 44% in G1, G2 and G3, respectively (P<.01) and biliary focus 6, 11 and 16% (P<.01), in each group. E. coli accounted for 32% in G1, 44% in G2 and 51% in G3. Mortality in each age group was 9, 16 and 21%. In multivariate analysis, mortality in the ≥80 years was associated with renal failure, malnutrition, the presence of ulcers and shock.

CONCLUSIONS

Bacteremia in the elderly are mainly of urinary origin. Mortality in these cases depends primarily on the patient's baseline status rather than their age.

Predictors of in-hospital mortality in elderly patients with bacteraemia admitted to an Internal Medicine ward

BACKGROUND

Infectious diseases are a common cause of increased morbidity and mortality in elderly patients. Bacteraemia in the elderly is a difficult diagnosis and a therapeutic challenge due to age-related vicissitudes and to their comorbidities. The main purpose of the study was to assess independent risk factors for in-hospital mortality among the elderly with bacteraemia admitted to an Internal Medicine Ward.

METHODS

Overall, a cohort of 135 patients, 65 years of age and older, with bacteraemia were retrospectively studied. Data related to demographic information, comorbidities, clinical parameters on admission, source and type of infection, microorganism isolated in the blood culture, laboratory data and empirical antibiotic treatment was recorded from each patient. Multivariate logistic regression was performed to identify independent predictors of all-cause in-hospital mortality.

RESULTS

Of these 135 patients, 45.9% were women. The most common infections in this group of patients were urinary tract infections (46.7%). The main microorganisms isolated in the blood cultures were Escherichia coli (14.9%), Methicillin-resistant Staphylococcus aureus (MRSA) (12.0%), non-MRSA (11.4%), Klebsiella pneumoniae (9.1%) and Enterococcus faecalis (8.0%). The in-hospital mortality was 22.2%. Independent prognostic factors associated with in-hospital mortality were age ≥ 85 years, chronic renal disease, bacteraemia of unknown focus and cognitive impairment at admission (OR, 2.812 [95% CI, 1.039-7.611; p = 0.042]; OR, 6.179 [95% CI, 1.840-20.748; p = 0.003]; OR, 8.673 [95% CI, 1.557-48.311; p = 0.014] and OR, 3.621 [95% CI, 1.226-10.695; p = 0.020], respectively). By multivariate analysis appropriate antibiotic therapy was not associated with lower odds of mortality.

CONCLUSION

Bacteraemia in the elderly has a high mortality rate. There are no set of signs or clinical features that can predict bacteraemia in the elderly. However, older age (≥ 85 years), chronic renal disease, bacteraemia of unknown focus and severe cognitive impairment adversely affects the outcome of elderly patients with bacteraemia admitted to an Internal Medicine ward.

Gram-negative bacterial endocarditis in adults: state-of-the-heart

Gram-negative endocarditis due to HACEK bacteria (Haemophilus species, Actinobacillus, Cardiobacterium, Eikenella and Kingella species) and non-HACEK organisms is an infrequent occurrence but is associated with significant morbidity and mortality. Traditionally, non-HACEK Gram-negative endocarditis has been associated with injection drug use. However, emerging data from more contemporary cohorts suggest changing epidemiology and risk factors for Gram-negative endocarditis, necessitating an updated review of this subject. Moreover, optimal management, including the need for surgical intervention, and strategies for the prevention of Gram-negative endocarditis need to be revisited.

Alterations of T cell activation signalling and cytokine production by postmenopausal estrogen levels

Background

Immunosenescence is an age-associated disorder occurring primarily in T cell compartments, including altered subset composition, functions, and activation. In women, evidence implicates diminished estrogen in the postmenopausal period as a contributing factor to diminished T cell responsiveness. Since hypoestrogenism is present in postmenopausal women, our objective focused on whether T cell activation, defined as signalling molecule expressions and activation, and function, identified as IL-2 production, were affected by low estrogen.

Methods

Using Jurkat 6.1 T cells, consequences of 4 pg/ml (corresponding to postmenopausal levels) or 40 pg/ml (premenopausal levels) of estradiol (E₂) were analyzed on signalling proteins, CD3-zeta, JAK2, and JAK3, determined by Western immunoblotting. These consequences were correlated with corresponding gene expressions, quantified by real time-polymerase chain reaction. Tyrosine phosphorylation of CD3-zeta was defined by immunoprecipitation and western immunoblotting following activation by T cell receptor (TcR) cross-linking. CD3-zeta expression and modulation was also confirmed in T cells from pre- and postmenopausal women. To assess functional consequences, IL-2 production, induced by PMA and ionomycin, was determined using enzyme-linked immunosorbent spot assay (ELISpot).

Results

At 40 pg/ml E₂, the level of signalling protein CD3-zeta was elevated 1.57-fold, compared with cells exposed to 4 pg/ml E₂. The CD3-zeta proteins also exhibited altered levels of activation-induced phosphorylation in the presence of 40 pg/ml E₂ versus 4 pg/ml: 23 kD phosphorylated form increased 2.64-fold and the 21 kD form was elevated 2.95-fold. Examination of kinases associated with activation signalling also demonstrated that, in the presence of 40 pg/ml E₂, JAK2 protein expression was increased 1.64-fold (p < 0.001) and JAK3 enhanced 1.79-fold (p < 0.001) compared to 4 pg/ml. mRNA levels for CD3-zeta, JAK2, and JAK3 were significantly increased following exposure to 40 pg/ml E₂ (2.39, 2.01, and 2.21 fold, respectively) versus 4 pg/ml. These findings were confirmed in vivo, since T cells from postmenopausal women exhibited 7.2-fold diminished CD3-zeta expression, compared to pre-menopausal controls and this expression was elevated 3.8-fold by addition of 40 pg/ml E₂. Functionally, Jurkat cells exposed to 40 pg/ml E₂ and activated exhibited significantly elevated numbers of IL-2 producing colonies compared to 4 pg/ml (75.3 ± 2.2 versus 55.7 ± 2.1 colonies, p < 0.0001).

Conclusion

Jurkat T cells exposed to 4 pg/ml E₂ expressed significantly diminished activation signalling proteins, correlating with reduced IL-2 production. Lower signalling protein levels appear to result from decreased CD3-zeta, JAK2, and JAK3 gene expressions. These findings may provide a molecular basis for immunosenescence associated with the postmenopausal state.

Shock settico

Lo shock settico corrisponde all’associazione di un’infezione e di un’insufficienza emodinamica, eventualmente associata ad altri deficit viscerali. Le definizioni assimilano spesso lo shock settico alla sepsi grave, la cui insufficienza emodinamica è considerata reversibile. I fondamenti del trattamento si basano su misure che si devono applicare in tempi brevi: il trattamento specifico, che corrisponde alla lotta contro l’agente infettivo, e il trattamento sintomatico, in particolare mediante il ripristino di un’emodinamica efficace. L’aumento del numero delle infezioni gravi e degli shock settici nei paesi industrializzati è stato all’origine di sforzi considerevoli allo scopo di migliorarne la gestione. In particolare, il frutto delle riflessioni congiunte di diverse società scientifiche è stato formalizzato in raccomandazioni, riassunte in procedure. In effetti, la strategia che mira a un miglioramento delle pratiche sembra ridurre la mortalità legata alle infezioni. Alcuni ostacoli compromettono tuttavia il loro uso, dal riconoscimento del problema all’organizzazione delle cure.

Short-term mortality in relation to age and comorbidity in older adults with community-acquired bacteremia: a population-based cohort study

OBJECTIVES

To assess 30-day mortality from bacteremia in relation to age and comorbidity and the association between age and mortality with increasing comorbidity.

DESIGN

Population-based cohort study.

SETTING

North Jutland County, Denmark.

PARTICIPANTS

Adults in medical wards with community-acquired bacteremia, 1995 to 2004.

MEASUREMENTS

Smoothed mortality curves and computed mortality rate ratios (MRRs) using Cox regression analysis.

RESULTS

Two thousand eight hundred fifty-one patients, 851 aged 15 to 64, 1,092 aged 65 to 79, and 909 aged 80 and older were included. Mortality increased linearly with age. Compared with patients younger than 65, adjusted MRRs in patients aged 65 to 79 and 80 and older were 1.5 (95% confidence interval (CI)=1.2-2.0) and 1.8 (95% CI=1.4-2.3), respectively. Mortality also increased with level of comorbidity. Compared with patients with low comorbidity, adjusted MRRs in patients with medium and high comorbidity were 1.5 (95% CI=1.2-1.8) and 1.7 (95% CI=1.4-2.2), respectively. Regardless of the level of comorbidity, MRRs were consistently higher in older than in younger patients.

CONCLUSION

Older age and greater comorbidity predicted mortality, and increasing age-related comorbidity did not explain the effect of age.

Severe sepsis and septic shock in the emergency department

Increased attention has focused recently on the acute management of severe sepsis and septic shock, conditions that represent the end-stage systemic deterioration of overwhelming infection. Clinical trials have identified new therapies and management approaches that, when applied early, appear to reduce mortality. Practice guidelines have been advanced by critical care societies, and many of the proposed interventions involve therapies other than antimicrobials directed at hemodynamic resuscitation or addressing adverse effects of the inflammatory cascade. Although many emergency departments (EDs) are now adopting treatment protocols for sepsis that are based on published treatment guidelines, recent research calls many of the initial recommendations into question, and validation trials of some of these approaches are ongoing. This article reviews the initial evaluation and treatment considerations of sepsis in the ED setting.

[Bacteremia in very elderly patients: risk factors, clinical characteristics and mortality]

INTRODUCTION

There is little information on bacteremia in very elderly patients. This study describes the characteristics of bacteremia in this population.

METHODS

This is a prospective study investigating bacteremia episodes in patients over 80 years old in comparison with episodes in patients aged 18-64 and 65-79 years.

RESULTS

A total of 146 bacteremia episodes were analyzed in patients over 80 years old. Comorbidity was documented in 66.4% and immunodeficiency in 6.8% of patients. Among the total, 82.2% had no underlying disease or a disease considered non-fatal. Eighty episodes were community-acquired. The main infectious foci included primary (25.3%) and urinary tract (20.5%) infection, and the most frequent isolates were Escherichia coli (28.2%), coagulase-negative Staphylococcus (14.7%) and S. aureus (13.6%). Sepsis or septic shock occurred in 55.5% of the cases, and 31 patients died due to a bacteremia-related cause. Immunodeficiency was less frequent in patients over 80 years old, but they had a higher proportion of community-acquired infections and gram-negative infections. Bacteremia-related mortality was highest in the oldest group of patients and was associated with a fatal or ultimately fatal underlying disease, S. aureus infection, and inappropriate empirical antibiotic treatment. A lower Pitt severity score was related to lower mortality risk.

CONCLUSIONS

Very elderly bacteremic patients showed a lower frequency of immunodeficiency, a higher percentage of community-acquired and gram-negative infections. Bacteremia-related mortality was greater in the most elderly group and was associated with fatal or ultimately fatal underlying disease, S. aureus infection and initiation of inappropriate empirical antibiotic treatment.

Comparison of clinical manifestations and outcome of community-acquired bloodstream infections among the oldest old, elderly, and adult patients

Valid studies comparing the clinical characteristics among adult, elderly, and the oldest old bacteremic patients are lacking. We conducted a prospective, observational study in the emergency department (ED) of a university medical center between June 2001 and June 2002. All patients >18 years of age who registered in the ED with a clinically significant, culture-positive, bloodstream infection (BSI) were enrolled. Patients were divided into 3 groups based on age: 1) oldest old (> or =85 yr), 2) elderly (65-84 yr), and 3) adult (18-64 yr). The clinical and laboratory manifestations and 30-day mortality were recorded. Group comparisons were performed using the chi-square test or analysis of variance (ANOVA) test, as indicated. Survival was analyzed using the Kaplan-Meier method and the Cox-regression model, adjusted for potential confounders.A total of 890 cases of community-acquired BSI were eligible for analysis. Compared to the adult group, both the elderly and the oldest old patients had more atypical clinical manifestations, a higher propensity to develop organ failure, and a worse prognosis. Elderly patients had significantly less tachycardia (p = 0.001), but more acute respiratory (p = 0.007) and renal failure (p = 0.037); the oldest old patients had more afebrile episodes (p = 0.006), leukocytosis (p = 0.012), and more patients developed respiratory failure (p = 0.009), acute renal failure (p = 0.011), septic shock (p = 0.022), and altered mental status (p = 0.013). Urinary tract infections were the main source of BSI for both the elderly and oldest old, while the oldest old patients had significantly more pneumonia than the elderly or adults. As a group, older patients had fewer signs and symptoms of BSI, but a higher risk of organ failure and a worse prognosis than younger patients.

Age- and gender-related differences of the immune function in a murine model of hemorrhagic shock: IL-10 restores immunodepression in aged females without reduction of mortality

INTRODUCTION

Interleukin-10 (IL-10) treatment has been shown to have beneficial effects on the immune function after hemorrhagic shock and to improve survival after subsequent sepsis in young male mice, but not in young females. Although it was demonstrated that the immune function under these conditions is reversed with age, it remains unclear whether the observed gender-related effect of IL-10 treatment continues to exist in aged mice.

MATERIALS AND METHODS

Aged male and female CBA/J mice (18-19 months) were subjected to hemorrhage (35 +/- 5 mmHg for 90 min) or sham operation. At resuscitation, each received either 10-microg recombinant murine (rm)IL-10 or placebo i.p. At 48 h after resuscitation, either the mice were killed and the plasma, splenic macrophages (sM phi), and splenocytes were harvested or polymicrobial sepsis was induced by cecal ligation and puncture (CLP). After CLP, either survival over 10 days was determined or, 4 h after CLP, tissues were again harvested and cytokine-released in vitro were assessed by enzyme-linked immunosorbent assay.

RESULTS

Early IL-10 treatment restored depressed proinflammatory immune response (TNF-alpha, IL-1 beta) and Th1 response of splenocytes in aged females after hemorrhage, whereas having no effects or having suppressive effects in aged males. Subsequent sepsis combined with placebo treatment led to a significant suppression of proinflammatory cytokine release of sM phi and a significant increase of Th2 response in both males and females associated with high mortality (80-100%, respectively) after CLP. These effects were not influenced by early rmIL-10 treatment.

CONCLUSION

After hemorrhage, early rmIL-10 treatment restored immune function in aged females, but not in males. However, in contrast to young mice, rmIL-10 treatment had no effect on survival and immune function after CLP in aged mice.

Young and middle-age associated differences in cytokeratin expression after bone fracture, tissue trauma, and hemorrhage

BACKGROUND

This study examined whether there is any difference in the lung cytokine and cytokeratin 19 levels between young and middle-aged mice after bone fracture and soft-tissue trauma hemorrhage (Fx-TH).

METHODS

Young (6-8 weeks) and middle-aged (12 months) C3H/HeN male mice were subjected to right lower leg fracture, trauma hemorrhage (mean arterial blood pressure to 35 +/- 5 mm Hg for 90 minutes), and resuscitation.

RESULTS

The tumor necrosis factor alpha level in the lung increased significantly at 2 hours after Fx-TH in both young and middle-aged mice, whereas at 24 hours the levels remained significantly higher in middle-aged mice. Interleukin-6 levels increased significantly 24 hours after Fx-TH in both groups, whereas interleukin-10 levels increased only in middle-aged mice at 24 hours under those conditions. Monocyte chemoattractant protein-1 levels increased significantly 2 hours after Fx-TH. The protein and messenger RNA levels of cytokeratin 19 were significantly higher in middle-aged mice compared with young mice after Fx-TH.

CONCLUSION

These results suggest that age influences the lung inflammatory response after Fx-TH.

Impact of sex and age on bone marrow immune responses in a murine model of trauma-hemorrhage

Although studies have demonstrated that trauma markedly alters the bone marrow immune responses, sex and age are crucial determinants under such conditions and have not been extensively examined. To study this, 21- to 27-day-old (premature), 6- to 8-wk-old (mature), and 20- to 24-mo-old (aged) male and female (proestrus) C3H/HeN mice were sham operated or subjected to trauma (i.e., midline laparotomy) and hemorrhagic shock (30 ± 5 mmHg for 90 min) followed by fluid resuscitation. Twenty-four hours after resuscitation, bone marrow cells were harvested. Trauma-hemorrhage induced an increased number of the early pluripotent stem cell-associated bone marrow cell subsets (Sca1+CD34−CD117+/−lin+/−) in young mice. The CD117+proportion of these cell subsets increased in mature proestrus females, but not in males. Aged males displayed significant lower numbers of Sca1+CD34−CD117+/−lin+/−cells compared with young male mice. Trauma-hemorrhage also increased development of granulocyte/macrophage progenitor cells (CD11b+Gr-1+). Proliferative responses to granulocyte macrophage colony-stimulating factor were maintained in mature and aged proestrus females, but decreased in young mice and mature males. Augmented differentiation into monocyte/macrophage lineage in mature and aged proestrus females was observed and associated with the maintained release of TNF-α and IL-6. Conversely, increased IL-10 and PGE2production was observed in the male trauma-hemorrhage groups. Thus, sex- and age-specific effects in bone marrow differentiation and immune responses after trauma-hemorrhage occur, which are likely to contribute to the sex- and age-related differences in the systemic immune responses under such conditions.

Clinical and microbiological characteristics in cases of positive blood cultures at Shin-Kokura Hospital during a period of 5 years

In order to evaluate the present state of bacteremia, we investigated the clinical and microbiological characteristics of positive blood culture cases hospitalized in Shin-Kokura Hospital from January 1998 through December 2002. Seventy-five cases showed positive blood cultures during the 5 years, and 48 cases (64%) were 70 years old or more. Most of the cases had underlying diseases, such as malignancy. The diagnoses of the infectious diseases found included pneumonia (9 cases), enteric infection (9 cases), hepatobiliary infection (8 cases), urinary tract infection (8 cases), and endocarditis (6 cases). A total of 102 strains of microorganism were isolated, and Gram-positive bacteria accounted for 64.7% of the cases, with Gram-negative bacteria accounting for 29.4%. Most of the isolated microorganisms showed good susceptibility to antimicrobial agents except for MRSA. Antimicrobial agents were used for 54 cases of bacteremia, and 33 patients improved, but 21 patients died, including 10 whose death was due to infection. In this study, the 54 cases of bacteremia (72% of all cases with a positive blood culture) showed a mortality rate of 18.5% due to infection, in spite of adequate antimicrobial treatment. Our data suggest that physicians should recognize the difficulty of treating bacteremia, and should pay close attention to the physical condition of patients with bacteremia.

Sexual dimorphism in innate immune responses to infectious organisms

Gender has long been known to be a contributory factor in the incidence and progression of disorders associated with immune system dysregulation. More recently, evidence has accumulated that gender may also play an important role in infectious disease susceptibility. In general, females generate more robust and potentially protective humoral and cell-mediated immune responses following antigenic challenge than their male counterparts. In contrast, males have frequently been observed to mount more aggressive and damaging inflammatory immune responses to microbial stimuli. In this article we review the evidence for sexual dimorphism in innate immune responses to infectious organisms and describe our recent studies that may provide a mechanism underlying gender-based differences in conditions such as bacterial sepsis.

Frequency of Permanent Pacemaker or Implantable Cardioverter-Defibrillator Infection in Patients with Gram-Negative Bacteremia

BACKGROUND

Despite the frequent occurrence of bacteremia due to gram-negative organisms in patients with underlying permanent pacemakers (PPMs) or implantable cardioverter defibrillators (ICDs), the outcome and treatment of these patients has received scant attention. In patients with PPMs or ICDs who have Staphylococcus aureus bacteremia, 45% have PPM/ICD infection.

METHODS

We conducted a retrospective cohort study over a 7-year period to assess the clinical features and frequency of PPM/ICD infection in patients with gram-negative bacteremia, as well as the incidence of relapse in patients for whom the device was not removed.

RESULTS

Forty-nine patients were included in the study; 3 (6%) had either definite (2 patients) or possible (1 patient) PPM/ICD infection. Both patients with definite PPM/ICD infection had clear infection of the generator pocket. None of the other patients with alternate sources of bacteremia developed PPM/ICD infection. Thirty-four patients with retained PPM/ICD were observed for >12 weeks (median time, 759 days), and 2 (6%) developed relapsing bacteremia, although they each had alternative sources of relapse.

CONCLUSIONS

In sharp contrast to S. aureus infection, PPM/ICD infection in patients with gram-negative bacteremia was rare, and no patients appeared to have secondary PPM/ICD infection due to hematogenous seeding of the system. Despite infrequent system removal in these patients, relapsing bacteremia among patients who survived initial bacteremia was rarely seen. If secondary PPM/ICD infection occurs in patients with gram-negative bacteremia, it is either uncommon or it is cured with antimicrobial therapy despite device retention.

Escherichia coli native valve endocarditis

Among 36 cases of Escherichia coli native valve endocarditis (NVE) that met Duke criteria (31 cases in the literature between 1909 and 2002, and five cases seen in Paris, France), the urinary tract was the most common portal of entry. The majority (72.2%) of cases developed in elderly females. Overall, the proportion of patients aged > 70 years rose from 5.3% in 1982 to 22.9% in 2002. Persistent E. coli bacteraemia in the elderly in the absence of cardiac risk-factors may be a sign of NVE and should prompt an investigation by echocardiography.

Severe sepsis and septic shock: review of the literature and emergency department management guidelines

Severe sepsis and septic shock are as common and lethal as other acute life-threatening conditions that emergency physicians routinely confront such as acute myocardial infarction, stroke, and trauma. Recent studies have led to a better understanding of the pathogenic mechanisms and the development of new or newly applied therapies. These therapies place early and aggressive management of severe sepsis and septic shock as integral to improving outcome. This independent review of the literature examines the recent pathogenic, diagnostic, and therapeutic advances in severe sepsis and septic shock for adults, with particular relevance to emergency practice. Recommendations are provided for therapies that have been shown to improve outcomes, including early goal-directed therapy, early and appropriate antimicrobials, source control, recombinant human activated protein C, corticosteroids, and low tidal volume mechanical ventilation.

Influence of gender and age on T-cell responses in a murine model of trauma-hemorrhage: differences between circulating and tissue-fixed cells

Clinical studies indicate that peripheral blood lymphocyte functions are depressed following trauma; however, it is unclear whether tissue-fixed lymphocyte functions are also altered under those conditions. Moreover, the impact of gender and age on peripheral T-cell responses following trauma-hemorrhage (TH) are unknown. To study this, immature (approximately 3 wk of age), mature (approximately 7 wk of age), and aged (approximately 23 mo of age) male and proestrus female C3H/HeN mice were sham operated or subjected to trauma (i.e., midline laparotomy) and hemorrhagic shock (30+/-5 mmHg for 90 min). Twenty-four hours after resuscitation, blood and splenocytes were harvested and T-cell functions assessed. In immature animals, TH induced an enhanced immune response in the splenic compartment and a suppressed response in the peripheral blood mononuclear cells (PBMC) that was independent of gender. Differential responses were observed in cells from mature mice. Splenic responses were enhanced following TH, independent of gender, whereas PBMC displayed gender dimorphism with suppressed proliferation and T-cell helper 1 responses in males but not in females. A similar pattern was observed in cells from aged mice. Splenic T cells from male mice displayed a suppressed CD4-to-CD8 ratio after TH, whereas no such change was observed in cells from proestrus females. In contrast, only PBMC from mature males displayed a suppressed CD4-to-CD8 ratio after TH. Thus gender differences exist in PBMC responses after TH that do not necessarily correlate with changes in the tissue-fixed compartment. Age is also an important factor in the immune responses after TH. In view of this, both gender and age should be taken into consideration in evaluating the immune status and in treatment of TH shock.

Nosocomial bacteremia in very old patients: predictors of mortality

BACKGROUND AND AIMS

Nosocomial Bacteremia (NB) is associated with high mortality in elderly patients. To determine specific prognostic factors for 7- and 30-day mortality in elderly patients with NB, we analysed the characteristics of 62 NB patients, retrospectively.

METHODS

This retrospective study concerns 62 cases of NB diagnosed within a 3-year period in a geriatric department. Bacteremia is described according to CDC definitions. Epidemiological characteristics, co-morbidities, clinical (activities of daily living (ADL) before NB) and biological findings (neutrophil count, lymphocyte count, albuminemia before NB) were collected for each patient. A systemic clinical reaction was defined by the presence of one of the following parameters: chills, hypothermia <36 degrees C or hyperthermia >38.5 degrees C, or shock. Types of micro-organism and source of NB were also collected. All variables were analysed for mortality at day 7 (7-day mortality) and at day 30 (30-day mortality).

RESULTS

The 7-day mortality rate was 21% and the 30-day rate was 45%. In multivariate analysis, 7-day mortality was only associated with the absence of systemic clinical reaction [OR 9.7 (3.7-25.7)]. Again, in multivariate analysis, 30-day mortality was associated with an ADL score <2 [OR 8.3 (4.3-16.4)] and cocci gram positive NB [OR= 3.6 (1.9-6.9)].

CONCLUSIONS

The absence of any systemic clinical reaction as a single independent predictor for 7-day mortality suggests either a poorer immune response to nosocomial bacteremia or a delay in diagnosis. Functional status was the strongest predictor for 30-day mortality. In this population, further prospective studies need to include these factors to evaluate predictors of mortality for serious infectious diseases.

Bacteraemia in the elderly: predictors of outcome in an urban teaching hospital

OBJECTIVES

To analyze the underlying factors of mortality in elderly adults with bacteraemia.

METHODS

The study included 238 episodes of bacteraemia in an urban public teaching hospital. Retrospective chart review recorded demographic information, comorbid conditions, length of stay, source of infection, and physiologic and laboratory data on admission.

RESULTS

Of the 238 episodes of bacteraemia, 128 patients were 65-74 years of age and 110 patients were > or =75 years of age. Eighty-one percent came from home. Fifty-four percent had Gram positive cocci detected in blood cultures and 36% had Gram negative bacilli. Factors associated with increased odds of mortality included underlying renal disease, admission to MICU, hypotension and hypoalbuminemia. Decreased odds of mortality were associated with being admitted from home and receiving appropriate antibiotics.

CONCLUSIONS

Bacteraemia in the elderly has a high mortality rate, but is not significantly increased in those >or =75 years of age. The recent microbiology has shifted from Gram negative bacilli to Gram positive cocci. Physiologic abnormalities on admission predict worse outcomes in the elderly bacteraemic patient. Hypoalbuminemia on admission is associated with higher mortality rates in the elderly.