Burden of bloodstream infection in older persons: a population-based study

Clinical features and risk factors of older adults with bloodstream infection

OBJECTIVE

To investigate the clinical features and risk factors of bloodstream infections in the older adults.

METHODS

This was a prospective cohort multicenter study. According to the inclusion and exclusion criteria, older adults with suspected bloodstream infections from December 2020 to June 2023 were included in the analysis of the clinical features of older adults bloodstream infections.

RESULTS

A total of 338 older adultswith suspected bloodstream infections were included, of which 141 were diagnosed with bloodstream infections. The proportion of gram-negative bacteria (47.5%) was close to that of gram-positive bacteria (46.1%), while the proportion of gram-negative bacteria was slightly higher.The common clinical manifestations of bloodstream infection were fever (75.2%), decreased level of consciousness (24.8%), chills (14.2%), shock (12.1%), etc.Multivariate regression analysis showed high procalcitonin levels at admission (OR = 2.008, 95%CI 1.258-3.206, P = 0.003) and heart rate > 90 beats/min (OR = 2.104, 95%CI 1.302-3.400). P = 0.002), arterial partial blood pressure of carbon dioxide < 32 mmHg (OR = 1.922, 95%CI 1.025-3.601, P = 0.042), and coronary heart disease (OR = 1.909, 95%CI 1.134-3.213), P = 0.015) were independent risk factors for bloodstream infection in the older adults.

CONCLUSION

The proportion of gram-negative and gram-positive bacteria in bloodstream infections in older adults was similar. The common clinical features of bloodstream infection in the older adults are fever and a decreased level of consciousness, and there was no significant difference in systemic clinical manifestations between bloodstream infection and non-bloodstream infection. High procalcitonin (PCT) level, heart rate > 90 beats/min, arterial partial pressure of carbon dioxide (PaCO2) < 32 mmHg, and underlying coronary heart disease were independent risk factors for bloodstream infection in older adults.

Machine learning model to predict sepsis in ICU patients with intracerebral hemorrhage

Patients with intracerebral hemorrhage (ICH) are highly susceptible to sepsis. This study evaluates the efficacy of machine learning (ML) models in predicting sepsis risk in intensive care units (ICUs) patients with ICH. We conducted a retrospective analysis on ICH patients using the MIMIC-IV database, randomly dividing them into training and validation cohorts. We identified sepsis prognostic factors using Least Absolute Shrinkage and Selection Operator (LASSO) and backward stepwise logistic regression. Several machine learning algorithms were developed and assessed for predictive accuracy, with external validation performed using the eICU Collaborative Research Database (eICU-CRD). We analyzed 2,214 patients, including 1,550 in the training set, 664 in the validation set, and 513 for external validation using the eICU-CRD. The Random Forest (RF) model outperformed others, achieving Area Under the Curves (AUCs) of 0.912 in training, 0.832 in internal validation, and 0.798 in external validation. Neural Network and Logistic Regression models recorded training AUCs of 0.840 and 0.804, respectively. ML models, especially the RF model, effectively predict sepsis in ICU patients with ICH, enabling early identification and management of high-risk cases.

Bacteremia in the Gulf Cooperation Council Region: A Review of the Literature 2013-2023

Bloodstream infections (BSIs) are amongst the leading healthcare-associated infections (HCAIs), and their comprehensive evaluation and management are of global and regional importance. This narrative review examines and reports data on BSIs from the Gulf Cooperation Council (GCC) region covering the period between 2013 and 2023. The reviewed literature demonstrated that BSIs were frequently associated with critical care settings such as the Intensive Care Unit (ICU) and were often associated with invasive lines and devices [such as central-line associated BSI (CLABSI)]. Fever was the main presenting symptom, while diabetes mellitus and hypertension were the common associated comorbidities. High mortality rates were reported for BSIs, particularly when caused by multidrug-resistant (MDR) Gram-negative pathogens. There was a wide range of antimicrobial resistance rates reported across the region; however, carbapenem-resistance rates exceeding 30% were reported for Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. Few publications included molecular mechanisms of carbapenem resistance; however, when mechanisms were reported they were dominated by OXA-48. In conclusion, the lack of structured surveillance programs and networks to monitor microbiological phenotypic and genotypic patterns as well as clinical outcomes across the region means there is paucity of uniform data on BSIs across the GCC region. To bridge this gap, we recommend timely surveillance programs for the monitoring of resistance and outcomes.

Research and predictive analysis of the disease burden of bloodstream infectious diseases in China

BACKGROUND

Bloodstream Infection(BSI) are one of the leading causes of infection-related mortality worldwide. However, epidemiological data related to BSI in China remain very limited.

METHODS

Based on the Global Burden of Disease(GBD) database, a systematic analysis was conducted on the epidemic trends, pathogen spectrum, and the current status of Antimicrobial Resistance(AMR) related to BSI in China for the year 2021. Additionally, an Autoregressive Integrated Moving Average(ARIMA) time series model was constructed to predict the trend of the disease burden associated with BSI in China from 2022 to 2035.

RESULTS

In terms of pathogens, the top five pathogens causing deaths due to BSI in China are as follows: Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. There are significant differences in the pathogens causing BSI across different age groups. The disease burden is heaviest in the elderly population aged 70 and above. Among children under five years old, Staphylococcus aureus, Streptococcus pneumoniae, and Candida species are predominant. From 1990 to 2021, although there has been a gradual decline in mortality rates due to BSI across different age groups (with an approximately 52.4% reduction in age-standardized rates), the disease burden of BSI increases with age. This is especially evident in the population aged 70 and above, where the burden of disease is significantly higher than in other age groups. For instance, in 2021, the mortality rate for individuals aged 70-74 was 149.29 (per 100 K), while for those aged 95 and older, the mortality rate reached as high as 896.71 (per 100 K). On a global scale, the disease burden caused by BSI in China is at a moderate level. According to time series model projections, the mortality burden of BSI in China shows a complex trend toward 2035: the crude mortality rate across all age groups is expected to increase by approximately 14.26%, whereas the age-standardized mortality rate and Disability-Adjusted Life Years(DALYs) are projected to decrease significantly. Notably, the mortality burden is expected to decline most prominently in the 70 + and under 5 age groups, while the 25-44 age group is projected to see minimal change. Conversely, the mortality rates for the 5-49 age group are anticipated to increase slightly.

CONCLUSION

Staphylococcus aureus and Escherichia coli are key pathogens contributing to the high mortality burden of BSI. Additionally, the heavy burden associated with AMR poses significant challenges to clinical treatment. From 1990 to 2021, the age-standardized mortality rate mortality of BSI patients is gradually decreasing, and the change in BSI mortality will be mainly affected by the changes in population size and age structure. The forecast analysis for 2022-2035 finds that the death burden of the elderly will be the heaviest, and the mortality of people aged 5-49 years will increase slightly. BSI and its related health problems are still major challenges and need continuous attention.

CLINICAL TRIAL

Inapplicability.

Antimicrobial susceptibility of gram-negative strains isolated from bloodstream infections in China: Results from the study for monitoring antimicrobial resistance trends (SMART) 2018-2020

The study aims were to present in vitro susceptibilities of clinical isolates from Gram-negative bacteria bloodstream infections (GNBSI) collected in China. GNBSI isolates were collected from 18 tertiary hospitals in 7 regions of China from 2018 to 2020. Minimum inhibitory concentrations were assessed using a Trek Diagnostic System. Susceptibility was determined using CLSI broth microdilution, and breakpoints were interpreted using CLSI M100 (2021). A total of 1,815 GNBSI strains were collected, with E. coli (42.4%) and Klebsiella pneumoniae (28.6%) being the most prevalent species, followed by P. aeruginosa (6.7%). Susceptibility analyses revealed low susceptibilities (<40%) of ESBL-producing E. coli and K. pneumonia to third-/fourth-generation cephalosporins, monobactamases, and fluoroquinolones. High susceptibilities to colistin (95.0%) and amikacin (81.3%) were found for K. pneumoniae, while Acinetobacter baumannii exhibited a high susceptibility (99.2%) to colistin but a low susceptibility to other antimicrobials (<27.5%). Isolates from ICUs displayed lower drug susceptibility rates of K. pneumoniae and A. baumannii than isolates from non-ICUs (all P < 0.05). Carbapenem-resistant and ESBL-producing K. pneumoniae detection was different across regions (both P < 0.05). E. coli and K. pneumoniae were major contributors to GNBSI, while A. baumannii exhibited severe drug resistance in isolates obtained from ICU departments.

Epidemiology and Resistance Profiles of Bacteria Isolated From Blood Samples in Septic Patients at Emergency Department Admission: A 6-Year Single Centre Retrospective Analysis From Northern Italy

OBJECTIVE

This study aimed to investigate the microbiological and clinical heterogeneity of community-onset bloodstream infections (BSIs) and identify features to support targeted empirical antibiotic therapy in the Emergency Department (ED).

METHODS

Clinical and microbiological data from 992 BSI cases (1,135 isolates) diagnosed within 24 h of ED admission at IRCCS Humanitas Research Hospital, Milan, Italy (January 2015-June 2022), were analysed. Drug resistance was interpreted using EUCAST-2023. Clinical features included age, sex, comorbidities (e.g., cancer, diabetes), infection source, presence of central venous catheters (CVC), ongoing therapies, and sepsis severity. Microbiological data included pathogen identification and antimicrobial susceptibility.

RESULTS

Antibiotic-susceptible Escherichia coli (29.5%) was the most common isolate, including extended-spectrum beta-lactamase (ESBL)-producing strains (11.3%), followed by methicillin-susceptible Staphylococcus aureus (MSSA, 8.4%). BSIs due to E. coli were more frequent in patients >60 years (43.9% vs. 27.3%, P < 0.001) and associated with ESBL production (OR = 2.202, P = 0.031) and urosepsis (OR = 1.688, P = 0.006). Younger patients (≤60 years) had more S. aureus-associated BSIs (22.4% vs. 10.8%, P < 0.001) and methicillin resistance (7.9% vs. 3.6%, P = 0.021). Carbapenem-resistant Enterobacterales were rare (2.1%-2.8%), predominantly involving Klebsiella pneumoniae. Onco-hematological patients had a lower multidrug-resistance prevalence (9.5% vs. 21.1%, P < 0.001).

CONCLUSIONS

Community-onset BSIs demonstrated substantial prevalence of resistant pathogens, including ESBL and MRSA, emphasizing the need for robust surveillance systems. Age is a critical factor in guiding empirical antibiotic therapy in the ED.

Incidence and resistance rates of Pseudomonas aeruginosa bloodstream infections in Switzerland: a nationwide surveillance study (2010-2022)

PURPOSE

Bloodstream infections (BSIs) cause significant morbidity and mortality worldwide. Pseudomonas aeruginosa is an important microorganism in BSIs. The aim of this study was to analyze recent trends in the incidence and resistance rates of P. aeruginosa BSIs in Switzerland and its different linguistic regions.

METHODS

This retrospective, nationwide observational study analyzed the incidence (using Poisson regression models) and antimicrobial resistance (using logistic regression models) of P. aeruginosa BSIs in Switzerland from 2010 to 2022.

RESULTS

The annual incidence of P. aeruginosa BSIs in Switzerland increased from 5.5 BSIs per 100,000 inhabitants in 2010 to 7.6 BSIs per 100,000 inhabitants in 2022 (p < 0.001). The incidence was higher in the French-speaking region than in the German-speaking region. The resistance rates increased significantly for cefepime (2.4% in 2010, 8.8% in 2022; p < 0.001), ceftazidime (5.6% in 2010, 9.4% in 2022; p = 0.014), ciprofloxacin (3.3% in 2010, 6.5% in 2022; p = 0.014), and piperacillin-tazobactam (6.4% in 2010, 11.2% in 2022; p = 0.002). No significant trends were observed for carbapenem-, aminoglycoside-, or multidrug-resistant P. aeruginosa. A high incidence was observed in patients ≥ 80 years, whereas resistance rates were high in young patients.

CONCLUSION

The increase in the incidence of P. aeruginosa BSIs emphasizes the importance of monitoring resistant and susceptible P. aeruginosa BSIs. Compared to the population-weighted mean resistance rates in Europe in 2022, those in Switzerland were lower, but an increase was observed for most antibiotics. The high resistance rates in young patients require further investigation.

Enhancing pathogens detection in suspected geriatric bloodstream infections using Nanopore-targeted sequencing

Bloodstream infections (BSIs) are a critical concern for elderly patients, where prompt and accurate diagnosis is vital for effective treatment. Traditional blood culture methods suffer from delayed results and susceptibility to false-negatives. Nanopore-targeted sequencing (NTS) offers rapid pathogen detection and reporting, presenting a promising alternative. However, the application of NTS for diagnosing suspected BSIs in geriatric patients remains insufficiently studied. We conducted a retrospective cohort study from January 2022 to January 2024, including 198 geriatric patients suspected of BSIs. We utilized NTS to detect pathogen characteristics and compared the effectiveness and consistency of NTS with simultaneous blood culture testing for pathogen detection. NTS demonstrated a pathogen detection rate of 61.1%. The most common bacterial pathogens were Escherichia coli and Staphylococcus aureus (each 7.7%), while Candida albicans was the most prevalent fungal pathogen (30%). Mixed-bacterial infections were detected in 21.7% of NTS-positive cases, and concurrent bacterial-fungal infections were observed in 9.92% of these cases. NTS-positive patients had higher rates of comorbidities, elevated inflammatory markers, and worse prognoses compared to NTS-negative patients. NTS exhibited a significantly higher pathogen detection rate and faster turnaround time than blood culture (78.1% vs 42.2%, P < 0.001), with an agreement rate of 65.6%. The elderly BSI patients frequently involve multiple or mixed infections and correlate with poorer prognoses. NTS provides a faster and more sensitive diagnostic alternative to traditional blood culture, potentially improving clinical outcomes and guiding more effective treatment strategies. This study highlights the need for further research to validate the routine clinical integration of NTS for managing BSIs in geriatric populations.

IMPORTANCE

Bloodstream infections (BSIs) in elderly patients pose substantial diagnostic and therapeutic challenges due to the limitations of traditional blood culture methods, which are hampered by slow turnaround times and false-negatives. Nanopore-targeted sequencing (NTS) emerges as a significant advancement, offering rapid and accurate pathogen detection directly from blood samples. This study demonstrates that NTS provides a higher detection rate and faster results than conventional blood cultures, crucial for the timely management of BSIs in geriatric patients, who often present with multiple or mixed infections and have poorer clinical outcomes. The findings underscore the potential of NTS to enhance diagnostic accuracy and speed, informing more effective treatment strategies and improving overall patient outcomes. Further research is essential to establish NTS as a routine diagnostic tool in the clinical management of BSIs in the elderly.

Evaluation of elderly patients with bacteremia in the cardiology intensive care unit

In this study, the blood culture results of patients aged >65 years who were admitted to the cardiology intensive care unit in a training and research hospital and who had positive blood cultures within the first 48 hours were evaluated. This was a retrospective, observational and nonrandomized study. Patient data at the time of the blood culture were included in the study. Sex, age, length of hospital stay, mortality, Acute Physiology Chronic Health Evaluation II score, laboratory values, and microorganisms grown in blood culture included in the study. Two hundred forty-seven patients, 43.3% of whom were female (n = 107), were included in the study. The median age of the patients was 75 (range 70-83). The mean hospital stay was 5 days (range 3-8). All patients had a median Acute Physiology Chronic Health Evaluation II score of 21 (range 19-23). The overall mortality rate 48.2% (n = 119). The results showed that 49.8% of those died and 50.2% of survivors had positive blood culture results. The most common gram-positive cocci in those died were Staphylococcus hominis (15.6%), Staphylococcus epidermis (14.8%), Enterococcus faecium (9.6%). The most common gram-negative cocci were Escherichia coli (9.6%), Klebsiella pneumoniae (9.6%), Acinetobacter baummanii (1.6%). With an increase in the elderly population, infection management in elderly patients hospitalized in cardiology intensive care units has become increasingly critical.

The Outcome of Hospital-Acquired Bloodstream Infection and Its Associated Factors in Critical Care Unit

Background

Hospital-acquired bloodstream infections (BSI) are associated with high morbidity and mortality rates. This study was conducted to describe the outcomes and the prognosis of hospital-acquired BSI in the Critical Care Unit, Hospital Pakar Universiti Sains Malaysia (HPUSM), as well as to identify associated factors of treatment failure and mortality at 28 days.

Methods

This prospective cohort study was conducted in the Critical Care Unit of HPUSM from September 2019 to March 2021. Eligible participants included patients with a positive blood culture recorded after 48 hours of admission to hospital.

Results

There was a total of 250 patients, whose positive blood cultures were isolated. The main isolated organisms were Klebsiella pneumonia (23.6%), Pseudomonas spp. (19.2%), Escherichia coli (12.8%) and Acinetobacter sp. (9.2%). The mortality of hospital-acquired BSI was 27.6%. Multiple logistic regression analysis revealed that age [adjusted odds ratio (OR) = 1.06; 95% confidence interval (CI): 1.03, 1.09; p < 0.001], cases with extended-spectrum beta-lactamases (ESBL) (adjusted OR = 5.57; 95% CI: 2.04, 15.21; p = 0.001), with multidrug-resistant (MDR) organisms (adjusted OR = 14.70; 95% CI: 3.97, 54.48; p < 0.001) and those with a sequential organ failure assessment (SOFA) score > 11 (adjusted OR = 4.16; 95% CI: 1.31, 13.19; p = 0.015) had statistically significant associations with treatment failure. Factors significantly associated with 28-day mortality included age (adjusted OR: 1.06: 95% CI; 1.03, 1.09; p < 0.001), MDR organisms (adjusted OR = 14.70; 95% CI: 3.97, 54.48; p < 0.001) and SOFA score > 11 (adjusted OR = 4.16; 95% CI: 1.31, 13.19; p = 0.015).

Conclusion

The elderly, ESBL, MDR organisms and high SOFA scores were associated with treatment failure and 28-day mortality in hospital-acquired BSI.

Computed tomography angiography and coronary artery disease-reporting and data system and a 5-year prognostic major adverse cardiovascular and cerebral event outcome study in a symptomatic Southeast Asian population

BACKGROUND

This study investigated the relationship between coronary artery disease-reporting and data system (CAD-RADS) for coronary computed tomography angiogram (CCTA) and major adverse cardiovascular and cerebral event (MACE) in a symptomatic Southeast Asian, Thai population over a 5-year period.

METHODS

A retrospective cohort study of Thai patients without known CAD who underwent CCTA for CAD symptoms. CCTA images and 5-year health data were reviewed for CAD-RADS and MACE. MACE consists of all-cause mortality, cardiovascular death, acute coronary syndrome, heart failure hospitalization, and stroke.

RESULTS

In total 336 patients were evaluated. The median follow-up period was 6.4 years. The overall MACE incidence was 63 cases (18.8%). The MACE event rate was progressively increased with higher CAD-RADS categories; CAD-RADS 3 [hazard ratio (HR), 3.62; P  = 0.015], CAD-RADS 4a (HR, 3.50; P  = 0.024), CAD-RADS 4b & 5 (HR, 7.56; P  = 0.001). The risk of MACE increased significantly in the moderate to severe CAD burden group (HR, 5.58; P  = 0.01). Kaplan-Meier curve showed a significant rise in MACE with higher CAD-RADS categories ( P  = 0.01).

CONCLUSION

CAD-RADS classification has a significant prognostic value in Southeast Asian, Thai population with cardiac symptoms.

Changing epidemiology and antimicrobial susceptibility of bloodstream infections at a Vietnamese infectious diseases hospital (2010-2020)

Bloodstream infection (BSI) poses a global health problem, with diverse organisms and rising antimicrobial resistance (AMR). Here, we characterized trends in BSI prevalence, AMR, and antibiotic use at a Vietnamese infectious diseases hospital from 2010 to 2020. Among 108,303 cultured blood samples, 8.8% were positive, yielding 7995 pathogens. Of 7553 BSI cases, 86.4% were community-acquired. BSI prevalence varied from 17 to 35 cases/1000 admissions/year, highest in HIV/hepatitis wards and patients >60. The in-hospital mortality or hospice discharge outcome was 21.3%. The top three pathogens, E. coli (24%), K. pneumoniae (8.7%) and S. aureus (8.5%) exhibited increasing prevalence and multidrug resistance. Pathogens like Cryptococcus neoformans (8.4%), Talaromyces marneffei (6.7%), and Salmonella enterica (6.5%) declined. E. coli and K. pneumoniae were prevalent in older adults with community-acquired BSIs. Antibiotic use reached 842.6 DOT/1000 PD and significantly reduced after an antibiotic control policy. Enhanced surveillance and antimicrobial stewardship are crucial for managing BSIs in Vietnam.

Impact of the COVID-19 pandemic on extended-spectrum β-lactamase producing Escherichia coli in urinary tract and blood stream infections: results from a nationwide surveillance network, Finland, 2018 to 2022

BACKGROUND

Before the COVID-19 pandemic there has been a constant increase in antimicrobial resistance (AMR) of Escherichia coli, the most common cause of urinary tract infections and bloodstream infections. The aim of this study was to investigate the impact of the COVID-19 pandemic on extended-spectrum β-lactamase (ESBL) production in urine and blood E. coli isolates in Finland to improve our understanding on the source attribution of this major multidrug-resistant pathogen.

METHODS

Susceptibility test results of 564,233 urine (88.3% from females) and 23,860 blood E. coli isolates (58.8% from females) were obtained from the nationwide surveillance database of Finnish clinical microbiology laboratories. Susceptibility testing was performed according to EUCAST guidelines. We compared ESBL-producing E. coli proportions and incidence before (2018-2019), during (2020-2021), and after (2022) the pandemic and stratified these by age groups and sex.

RESULTS

The annual number of urine E. coli isolates tested for antimicrobial susceptibility decreased 23.3% during 2018-2022 whereas the number of blood E. coli isolates increased 1.1%. The annual proportion of ESBL-producing E. coli in urine E. coli isolates decreased 28.7% among males, from 6.9% (average during 2018-2019) to 4.9% in 2022, and 28.7% among females, from 3.0 to 2.1%. In blood E. coli isolates, the proportion decreased 32.9% among males, from 9.3 to 6.2%, and 26.6% among females, from 6.2 to 4.6%. A significant decreasing trend was also observed in most age groups, but risk remained highest among persons aged ≥ 60 years.

CONCLUSIONS

The reduction in the proportions of ESBL-producing E. coli was comprehensive, covering both specimen types, both sexes, and all age groups, showing that the continuously increasing trends could be reversed. Decrease in international travel and antimicrobial use were likely behind this reduction, suggesting that informing travellers about the risk of multidrug-resistant bacteria, hygiene measures, and appropriate antimicrobial use is crucial in prevention. Evaluation of infection control measures in healthcare settings could be beneficial, especially in long-term care.

Development of two multiplex PCR assays for rapid detection of eleven Gram-negative bacteria in children with septicemia

AIM

This study aimed to develop a multiplex PCR assay for simultaneous detection of major Gram-negative etiologies of septicemia and evaluate its performance.

METHODS

Multiplex PCR (mPCR) assays were developed targeting 11 bacterial strains. Species-specific primers were confirmed using known clinical isolates and standard strains. Gradient PCR was performed on each primer against its target bacterial gene to determine its optimal amplification condition. The minimum detectable DNA concentration of the two assays was evaluated by adjusting bacterial DNA concentration to 100 ng/μL and, tenfold serially diluting it up to 10 pg/μL with DNAse-free water. The diagnostic accuracy of mPCR assays was established by subjecting the assays to 60 clinical blood samples.

RESULTS

Two mPCR assays were developed. Optimal primer annealing temperature of 55 °C was established and utilized in the final amplification conditions. The assays detected all targeted bacteria, with a 100 pg minimum detectable DNA concentration. Pathogens were not detected directly from whole blood, but after 4 h and 8 h of incubation, 41% (5/12) and 100% (12/12) of the bacteria were detected in culture fluids, respectively. The assays also identified Salmonella spp. and Klebsiella pneumoniae co-infections and extra pathogens (1 E. coli and 2 K. pneumoniae) compared with culture. The sensitivity and specificity of the mPCR were 100.0% (71.7-100.0) and 98.0% (90.7-99.0), respectively. The area under the ROC curve was 1.00 (1.00-1.00).

CONCLUSIONS

The mPCR assays demonstrated substantial potential as a rapid tool for septicemia diagnosis alongside the traditional blood culture method. Notably, it was able to identify additional isolates, detect co-infections, and efficiently detect low bacterial DNA loads with high sensitivity, implying its value in enhancing efficiency of diagnosis of septicemia.

Comparing the Prognostic Impacts of Delayed Administration of Appropriate Antimicrobials in Older Patients with Afebrile and Febrile Community-Onset Bacteremia

Although prompt administration of an appropriate antimicrobial therapy (AAT) is crucial for reducing mortality in the general population with community-onset bacteremia, the prognostic effects of delayed AAT in older individuals with febrile and afebrile bacteremia remain unclear. A stepwise and backward logistic regression analysis was used to identify independent predictors of 30-day mortality. In a 7-year multicenter cohort study involving 3424 older patients (≥65 years) with community-onset bacteremia, febrile bacteremia accounted for 27.1% (912 patients). A crucial association of afebrile bacteremia and 30-day mortality (adjusted hazard ratio [AHR], 1.69; p < 0.001) was revealed using Cox regression and Kaplan-Meier curves after adjusting for the independent predictors of mortality. Moreover, each hour of delayed AAT was associated with an average increase of 0.3% (adjusted odds ratio [AOR], 1.003; p < 0.001) and 0.2% (AOR, 1.002; p < 0.001) in the 30-day crude mortality rates among patients with afebrile and febrile bacteremia, respectively, after adjusting for the independent predictors of mortality. Similarly, further analysis based on Cox regression and Kaplan-Meier curves revealed that inappropriate empirical therapy (i.e., delayed AAT administration > 24 h) had a significant prognostic impact, with AHRs of 1.83 (p < 0.001) and 1.76 (p < 0.001) in afebrile and febrile patients, respectively, after adjusting for the independent predictors of mortality. In conclusion, among older individuals with community-onset bacteremia, the dissimilarity of the prognostic impacts of delayed AAT between afebrile and febrile presentation was evident.

Species Distribution, Typical Clinical Features and Risk Factors for Poor Prognosis of Super-Elderly Patients with Bloodstream Infection in China

Objective

Bloodstream infection (BSI) is characterized by high mortality, especially among these increasing super-elderly patients (≥85 years), and this study was conducted to understand the species distribution, typical clinical features and risk factors for poor prognosis of super-elderly patients with BSI.

Methods

Based on previous work, this retrospective study was performed by reviewing an ongoing prospective medical database in a comprehensive tertiary center in China, and all super-elderly patients with BSI in the past 6 years were enrolled in this study.

Results

Out of 5944 adult-patients with BSI, there were totally 431 super-elderly patients (≥85 years old) enrolled in this study and age ≥90 years accounted for 31.1% (134/431). Among these 431 super-elderly patients with BSI, 40 patients (9.3%) were diagnosed with BSI and the remained 401 super-elderly patients (90.7%) were defined as hospital-acquired BSI. The typical feature of these super-elderly patients with BSI was the high proportion of patients with various comorbidities, such as cardiovascular disease (83.8%), ischemic cerebrovascular disease (63.3%) and pulmonary infection (61.0%). The other typical feature was that most (60.1%) of these patients had been hospitalized for long time (≥28 days) prior to the onset of BSI, and most patients had received various invasive treatments, such as indwelling central venous catheter (53.1%) and indwelling urinary catheter (47.1%). Unfortunately, due to these adverse features above, both the 7-day short-term mortality (13.2%, 57/431) and the 30-day long-term mortality (24.8%, 107/431) were high. The multivariate analysis showed that both chronic liver failure (OR 7.9, 95% CI 2.3-27.8, P=0.001) and indwelling urinary catheter (OR 2.3, 95% CI 1.1-4.7, P=0.023) were independent risk factors for 7-day short-term mortality, but not for 30-day long-term mortality. In addition, the microbiology results showed that the most common species were associated with nosocomial infection or self-opportunistic infection, such as Staphylococcus hominis (18.3%), Staphylococcus epidermidis (11.8%), Escherichia coli (9.7%), Klebsiella pneumoniae (9.3%) and Candida albicans (8.6%, fungi).

Conclusion

Super-elderly patients with BSI had typical features, regardless of the pathogenic species distribution and their drug resistance, or clinical features and their risk factors for poor prognosis. These typical features deserved attention and could be used for the prevention and treatment of BSI among super-elderly patients.

Bloodstream infections in the elderly Japanese population: Current reality and countermeasures

We reviewed bloodstream infections in the elderly in Japan, referring to data recently reported from the National Center for Global Health and Medicine in Tokyo. We divided the locations of bloodstream infections into Hospital-onset (HO), healthcare-associated (HCA), and CA (community-acquired), as the elderly reside in different places. The study focused on the fact that the general condition and underlying diseases of the elderly differ by age group. And thus, we divided them into three groups: Pre-old (65-74 years), Old (75-89 years), and Super-old (≥ 90 years), and compared their characteristics of bloodstream infections. HO bacteremia was most common in the pre-old group. On the other hand, HCA bloodstream infections tended to increase as the population aged, and it was most prevalent in super-old group. According to the study results, early intervention through infectious diseases (ID) consultation may improve the prognosis of bloodstream infections even in the elderly. Since the rate of ID consultation is lower in the super-old group than in other groups, this group may be a significant target. In conclusion, a study of a cohort of elderly patients with bloodstream infections in Japan indicates that bloodstream infections in patients over 65 years is not uniform.

Empirical antibiotic therapy modalities for Enterobacteriaceae bloodstream infections in older patients and their impact on mortality: a multicentre retrospective study

PURPOSE

Enterobacteriaceae (EB) bloodstream infections (BSI) are frequent and serious in older patients. Physicians are faced with the dilemma of prescribing early appropriate empirical antibiotics to limit the risk of death, and sparing broad-spectrum antibiotic prescription. The aim of the study was to assess the rate of appropriate empirical antibiotics prescription to treat EB BSI in older patients and its impact on survival.

METHODS

This study conducted in 49 centres enrolled retrospectively up to the 10 last consecutive patients aged 75 years and over and treated for EB BSI. Factors related to in-hospital death were investigated using logistic regression.

RESULTS

Among the 487 enrolled patients (mean age 86 ± 5.9 years), 70% had at least one risk factor of being infected by third-generation cephalosporins (3GC)-resistant strain; however, only 13.8% of EB strains were resistant to 3GC. An empirical antimicrobial treatment was initiated for 418 patients (85.8%), and for 86% (n = 360/418) of them, it was considered appropriate. In-hospital mortality was 12.7% (n = 62) and was related to the severity of infection (OR 3.17, CI 95% 1.75-5.75), while a urinary portal of entry was protective (OR 0.34, CI 95% 0.19-0.60). Neither the absence of nor inappropriate empirical antibiotics prescription was associated with increased mortality.

CONCLUSION

While patients enrolled in this study were at risk of being infected by multidrug-resistant bacteria, yet mainly treated with 3GC, empirical antibiotics prescription was appropriate in most cases and did not influence mortality.

The critically ill older patient with sepsis: a narrative review

Sepsis is a significant public health concern, particularly affecting individuals above 70 years in developed countries. This is a crucial fact due to the increasing aging population, their heightened vulnerability to sepsis, and the associated high mortality rates. However, the morbidity and long-term outcomes are even more notable. While many patients respond well to timely and appropriate interventions, it is imperative to enhance efforts in identifying, documenting, preventing, and treating sepsis. Managing sepsis in older patients poses greater challenges and necessitates a comprehensive understanding of predisposing factors and a heightened suspicion for diagnosing infections and assessing the risk of sudden deterioration into sepsis. Despite age often being considered an independent risk factor for mortality and morbidity, recent research emphasizes the pivotal roles of frailty, disease severity, and comorbid conditions in influencing health outcomes. In addition, it is important to inquire about the patient's preferences and establish a personalized treatment plan that considers their potential for recovery with quality of life and functional outcomes. This review provides a summary of the most crucial aspects to consider when dealing with an old critically ill patient with sepsis.

Clinical outcomes and epidemiological characteristics of bacteremia in the older Japanese population

BACKGROUND

The characteristics and clinical consequences of bacteremia in older people, who are highly susceptible to infections, need to be clarified. This study aimed to determine the epidemiological characteristics, prognosis, and predictors of 7-day mortality in patients with community-acquired (CA), healthcare-associated (HCA), and hospital-onset (HO) bacteremia in older adults aged ≥65 years.

METHODS

Patients aged ≥65 years with positive blood cultures between April 1, 2015, and March 31, 2018, were divided into three groups: pre-old (65-74 years), old (75-89 years), and super-old (≥90 years). Characteristics based on medical exposure, including CA, HCA, and HO, were also compared and factors related to mortality were identified.

RESULTS

Overall, 1716 episodes of bacteremia were identified in 1415 patients. Of the 1211 episodes without contamination, 32.8%, 54.3%, and 12.9% occurred in pre-old, old, and super-old patients. Central line-associated bloodstream infections were more common in pre-old patients and urinary tract infections in the old and super-old. The 7-day mortality rates in the pre-old, old, and super-old groups were 7.4%, 5.8%, and 14.2% (P = 0.002), respectively. Multivariable logistic regression showed that super-old age (adjusted odds ratio, aOR: 2.09 [1.13-3.88], P = 0.019) and HO bacteremia (aOR: 1.97 [1.18-3.28], P = 0.010) were independent risk factors for 7-day mortality. Infectious disease consultation had a protective effect on 7-day mortality (aOR: 0.59 [0.35-0.99], P = 0.047).

CONCLUSIONS

The epidemiology of bacteremia differs among older people; thus, they should not be treated as a single entity. A careful approach is needed for the optimal management of bacteremia in these vulnerable patients.

Bloodstream infections and antibiotic resistance patterns: a six-year surveillance study from southern Italy

Bloodstream infections (BSI) are associated with high morbidity and mortality. This study aimed to describe the epidemiology of BSI and antimicrobial resistance patterns amongst its common bacterial causes. We conducted a retrospective record review of blood culture results of patients hospitalized with BSI at University Hospital 'L. Vanvitelli' from 2016 to 2021. For each patient records were obtained from the database using microbiological information. Gram-positive bacteria were the most predominant pathogens followed by Gram-negative bacteria. Among all isolates, bacterial pathogens most frequently identified included coagulase-negative Staphylococci (CoNS), Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and enterococci. We noted a general decrease in antimicrobial resistance amongst BSI pathogens in the latter years of the study. High levels of macrolide and aminoglycoside resistance amongst CoNS were reported. Carbapenem resistance amongst E. coli was barely reported, while resistance rates amongst K. pneumoniae declined considerably between 2018 and 2021. The prevalence of methicillin-resistant S. aureus decreased during the study period while that of methicillin-resistant CoNS remained relatively high throughout. The prevalence of extended spectrum ß-lactamase - producing E. coli increased considerably between 2016 and 2018 but showed a slight decrease thereafter. Conversely, there was a general decline in the resistant rates of extended spectrum ß-lactamase - producing K. pneumoniae between 2016 and 2018 with a similar trend being noted for carbapenem resistance in K. pneumoniae. Continuously monitoring the changes in the trends in BSI microbiological profiles, including pathogen profiles and the associated antibiotic resistance patterns, can help diagnostic approaches, treatment strategies and prevention programs.

Clinical evaluation of polymerase chain reaction coupled with quantum dot fluorescence analysis in the identification of bacteria and yeasts in patients with suspected bloodstream infections

Bloodstream infections are serious and complex infectious diseases that often require a rapid diagnosis. Polymerase chain reaction coupled with quantum dot fluorescence analysis (PCR-QDFA) is a novel diagnostic technique. This study aimed to evaluate the diagnostic performance of PCR-QDFA for pathogen detection in patients with suspected bloodstream infections (BSIs). It evaluates 29 kinds of common pathogens (24 bacteria and 5 yeasts) from blood culture bottles. The results of PCR-QDFA identification and traditional microbial laboratory identification were compared, and the latter was used as the 'gold standard' to analyse the diagnostic performance of the PCR-QDFA. In total, 517 blood culture bottles were included in this study. The PCR-QDFA identified microorganisms in 368/422 (87.2%) samples with monomicrobial growth. For the pathogens on the PCR-QDFA list, the assay showed a higher sensitivity of 97.4% (368/378). When polymicrobial growth was analysed, the PCR-QDFA successfully detected 19/25 (76%) microorganisms on the PCR-QDFA list. In addition, 82/82 negative blood culture bottles also showed no pathogens by PCR-QDFA with a specificity of 100%. In conclusion, the PCR-QDFA assay could identify a majority of the common pathogens encountered in clinical practice, showing excellent diagnostic performance for pathogen detection in patients with suspected BSIs.

Intrinsic values of procalcitonin in bacterial bloodstream infections in people aged 75 years and over: a retrospective study

OBJECTIVE

To evaluate PCT measurement in the diagnosis of bloodstream infection (BSI) in hospitalized patients aged 75+.

METHOD

Descriptive, retrospective, monocentric study conducted in France, in patients with at least one blood culture and PCT and CRP measurements within the 24 hours before or after blood culture.

RESULTS

The mean PCT and CRP values for the 118 (15.2%) positive blood cultures were 18.90 ng/ml [95%CI: 0.007-334.7] and 153.93 mg/l [1-557], respectively. With a threshold of 0.3 ng/ml, PCT measurement had a sensitivity of 84%, a specificity of 53%, a PPV of 24%, and an NPV of 95%, making it possible to rule out BSI in 350 (45.1%) patients (α-risk=5%).

CONCLUSION

PCT measurement may eliminate BSI diagnosis more quickly than does blood culture reducing the inadequate and detrimental use of antibiotic therapy. A prospective study is required to validate its usefulness and confirm the cut-off value in geriatric populations.

Outcomes and Predictors of In-Hospital Mortality among Older Patients with Dementia

Dementia is associated with high rates of admission to hospital, due to acute illness, and in-hospital mortality. The study aimed to investigate the impact of dementia on in-hospital mortality and identify the predictors of in-hospital mortality in these patients. This was a retrospective study evaluating all the patients ≥65 years consecutively admitted to our Emergency Department (ED). We compared the clinical outcomes of the patients with dementia at ED admission with those who did not have dementia, using a propensity score-matched (PSM) paired cohort of controls. The patients were matched for age, sex, Charlson Comorbidity Index value, and clinical severity at presentation (based on NEWS ≥ 5). The primary study endpoint was all-cause in-hospital death. After the PSM, a total of 7118 patients, 3559 with dementia and 3559 in the control group, were included in the study cohort. The mean age was 84 years, and 59.8% were females. The overall mortality rate was higher for the demented patients compared with the controls (18.7% vs. 16.0%, p = 0.002). The multivariate-adjusted hazard ratio (HR) showed that dementia was an independent risk factor for death (HR 1.13 [1.01−1.27]; p = 0.033). In the patients with dementia, respiratory failure (HR 3.08 [2.6−3.65]), acute renal failure (HR 1.64 [1.33−2.02]; p < 0.001), hemorrhagic stroke (HR 1.84 [1.38−2.44]; p < 0.001), and bloodstream infection (HR 1.41 [1.17−1.71]; p = 0.001) were significant predictors of worse outcomes. Finally, the comorbidities and severity of illness at ED admission negatively influenced survival among the patients with dementia (CCI HR 1.05 [1.01−1.1] p = 0.005; NEWS ≥ 5 HR 2.45 [1.88−3.2] p < 0.001). In conclusion, among the hospitalized older patients, dementia was associated with a higher risk of mortality. Furthermore, among the older patients with dementia, respiratory failure and bloodstream infections were independently associated with an increased risk of in-hospital mortality.

Preventing healthcare-related infections among older adults: a focus on cross-transmission of antibiotic-resistant bacteria

INTRODUCTION

Older individuals (i.e. age ≥65 years) are at increased risk for development of infections including those due to antimicrobial-resistant bacteria, and transmission may occur between institutional and community settings.

AREAS COVERED

This article reviews infections in older individuals with a specific focus on healthcare-related and antimicrobial resistant infections. A structured narrative review was performed to identify articles published in English since 2010. Themes included defining the scope of the problem, establishing characteristics of older individuals that impact the burden of resistant infections, and interventions aimed at minimizing their impact.

EXPERT OPINION

Older individuals suffer a high burden of illness related to antimicrobial resistant infections. Individuals with chronic illnesses, frailty, and residents of nursing homes are at highest risk. Clinical trials have shown that antimicrobial stewardship interventions may reduce antibiotic use in nursing homes without compromising safety. Antimicrobial resistant bacteria are prevalent among nursing home residents, and bundled infection prevention and control interventions can reduce their transmission. Transmission of antimicrobial resistant bacteria occurs among older adults across hospital and institutional settings, which may further spread to the community. The burden of infections in older adults is expected to increase in the coming years and represents a healthcare and research priority.

Explaining sex differences in risk of bloodstream infections using mediation analysis in the population-based HUNT study in Norway

Previous studies indicate sex differences in incidence and severity of bloodstream infections (BSI). We examined the effect of sex on risk of BSI, BSI mortality, and BSI caused by the most common infecting bacteria. Using causal mediation analyses, we assessed if this effect is mediated by health behaviours (smoking, alcohol consumption), education, cardiovascular risk factors (systolic blood pressure, non-HDL cholesterol, body mass index) and selected comorbidities. This prospective study included 64,040 participants (46.8% men) in the population-based HUNT2 Survey (1995-1997) linked with hospital records in incident BSI. During median follow-up of 15.2 years, 1840 (2.9%) participants (51.3% men) experienced a BSI and 396 (0.6%) died (56.6% men). Men had 41% higher risk of first-time BSI (95% confidence interval (CI), 28-54%) than women. Together, health behaviours, education, cardiovascular risk factors and comorbidities mediated 34% of the excess risk of BSI observed in men. The HR of BSI mortality was 1.87 (95% CI 1.53-2.28), for BSI due to S. aureus 2.09 (1.28-2.54), S. pneumoniae 1.36 (1.05-1.76), E. coli 0.97 (0.84-1.13) in men vs women. This study shows that men have higher risk of BSI and BSI mortality than women. One-third of this effect was mediated by potential modifiable risk factors for incident BSI.

Unresolved issues in the epidemiology and diagnosis of bacteremia: an opinion paper

Bacteremia is an important cause of morbidity and mortality worldwide and, despite the diagnostic and therapeutic advances of the last decades, the evidence supporting many diagnostic aspects of bacteremia is scarce. Information on the epidemiological evolution of this entity is limited and many methodological aspects of blood culture collection and analysis are under discussion. Furthermore, the recommendations of the main scientific societies on many of these aspects are variable and, in many cases, have not been updated recently. In this scenario, we have arranged a series of questions on different aspects of bacteremia and reviewed the literature trying to find proper answers for them. We offer our opinion on the topics where the evidence was weak. The topics covered include epidemiological aspects of bacteremia, indications for blood culture extraction, methods for obtaining and incubating samples, or ways of transmitting results from the microbiology laboratory. We do not intend to summarize the current clinical practice guidelines, nor will we deal with the therapeutic management of this entity. The aim of this paper is to review the current perspective on the diagnosis of bacteremia with a critical approach, to point out the gaps in the literature, to offer the opinion of a team dedicated to infectious diseases and clinical microbiology, and to identify some areas of knowledge on which future studies should focus.

Prognostic Effects of Delayed Administration of Antimicrobial Therapy in Older Persons Experiencing Bacteremia With or Without Initial Sepsis Presentations

OBJECTIVES

To investigate the prognostic effects of delayed administration of appropriate antimicrobial therapy (AAT) in older persons experiencing bacteremia with and without initial sepsis syndrome, respectively.

DESIGN

A 4-year multicenter cohort study.

SETTING AND PARTICIPANTS

Older people (≥65 years of age) with community-onset bacteremia in the emergency department (ED) of 3 participating hospitals.

METHODS

Clinical data were retrospectively collected and causative microorganisms were prospectively collected for susceptibilities to determine the period of delayed AAT for each bacteremia episode. Sepsis was defined based on the Sepsis-3 criteria. A multivariable regression model was used to investigate the prognostic effects of delayed AAT, after adjusting independent determinants of 30-day mortality.

RESULTS

Of the total 2357 patients, their median (interquartile range) age was 78 (72-84) years and septic patients accounted for 48.4% (1140 patients) of the overall patients. Compared with nonseptic patients, septic individuals exhibited the shorter period of delayed AAT (median, 2.0 vs 2.5 hours; P < .001), longer hospitalization (median, 11 vs 9 days; P < .001), and higher crude mortality rates at 15 (28.9% vs 2.1%; P < .001) and 30 days (34.6% vs 4.0%; P < .001). In multivariable regression analyses, each hour of delayed AAT resulted in average increases in the 30-day crude mortality rates of 0.38% [adjusted odds ratio (AOR) 1.0038; P < .001), 0.42% (AOR 1.0042; P < .001), and 0.31% (AOR 1.0031; P = .04) among overall, septic, and nonseptic patients, respectively.

CONCLUSIONS AND IMPLICATIONS

For older persons with community-onset bacteremia, irrespective of whether or not patients experiencing initial sepsis presentations, the prognostic impacts of delayed AAT have been evidenced. Notably, because of the longer period of delayed AAT in patients without fulfilling the Sepsis-3, adopting a stricter sepsis definition and/or early bacteremia predictor to avoid delayed AAT and unfavorable prognoses in patients with bacteremia is necessary.