Secular trends in incidence and mortality of bacteraemia in a Danish county 1981-1994

Risk of infective endocarditis and complicated infection in Staphylococcus aureus bacteremia - a retrospective cohort study on the role of bacteriuria

PURPOSE

S. aureus bacteremia (SAB) is a common and severe infection with high mortality and morbidity. The clinical relevance of the finding of concurrent S. aureus bacteriuria (SABU) is debated. The goal of this study was to analyze whether a concurrent SABU is associated with complicated SAB, infective endocarditis (IE) and mortality.

METHODS

We conducted a retrospective cohort study, reviewing medical charts of all episodes of SAB in patients > 18 years in the region of Skåne, Sweden, between 1st of January and 31st of June 2020. Episodes where a concurrent urine culture was performed were included for analysis. An episode was considered as complicated SAB if there was either attributable mortality, recurrent infection, embolic stroke, or occurrence of a complicated focus of infection.

RESULTS

During the study period, there were 279 episodes of SAB. 154 episodes met the eligibility criteria, of whom 37 (24%) had concurrent SABU. In 78 episodes (51%), the patients had a complicated SAB. There was a significantly lower proportion of complicated SAB for episodes with concurrent SABU (32%), compared to episodes without concurrent SABU (56%), p-value 0.014. Moreover, in the cohort there were 11 episodes (7.1%) of IE and a 30 days mortality rate of 16%, with no difference between the groups with or without SABU.

CONCLUSIONS

There is an association between concurrent SABU and a decreased risk for complicated SAB among patients with SAB. This study found no significant association between SABU and neither IE nor mortality for patients with SAB.

Fingerprints of Element Concentrations in Infective Endocarditis Obtained by Mass Spectrometric Imaging and t-Distributed Stochastic Neighbor Embedding

Staphylococcus aureus-induced infective endocarditis (IE) is a life-threatening disease. Differences in virulence between distinct S. aureus strains, which are partly based on the molecular mechanisms during bacterial adhesion, are not fully understood. Yet, distinct molecular or elemental patterns, occurring during specific steps in the adhesion process, may help to identify novel targets for accelerated diagnosis or improved treatment. Here, we use laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) of post-mortem tissue slices of an established mouse model of IE to obtain fingerprints of element distributions in infected aortic valve tissue. Three S. aureus strains with different virulence due to deficiency in distinct adhesion molecules (fibronectin-binding protein A and staphylococcal protein A) were used to assess strain-specific patterns. Data analysis was performed by t-distributed stochastic neighbor embedding (t-SNE) of mass spectrometry imaging data, using manual reference tissue classification in histological specimens. This procedure allowed for obtaining distinct element patterns in infected tissue for all three bacterial strains and for comparing those to patterns observed in healthy mice or after sterile inflammation of the valve. In tissue from infected mice, increased concentrations of calcium, zinc, and magnesium were observed compared to noninfected mice. Between S. aureus strains, pronounced variations were observed for manganese. The presented approach is sensitive for detection of S. aureus infection. For strain-specific tissue characterization, however, further improvements such as establishing a database with elemental fingerprints may be required.

Clinical and Microbiological Characteristics of Recurrent Escherichia coli Bacteremia

The causative agents of recurrent Escherichia coli bacteremia can be genetically identical or discordant, but the differences between them remain unclear. This study aimed to explore these differences, with regard to their clinical and microbiological features. Patients were recruited from a Japanese tertiary teaching hospital based on blood culture data and the incidence of recurrent E. coli bacteremia. We compared the patients' clinical and microbiological characteristics between the two groups (those with identical or discordant E. coli bacteremia) divided by the result of enterobacterial repetitive intergenic consensus PCR. Among 70 pairs of recurrent E. coli bacteremia strains, 49 pairs (70%) were genetically identical. Patients with genetically identical or discordant E. coli bacteremia were more likely to have renal failure or neoplasms, respectively. The virulence factor (VF) scores of genetically identical E. coli strains were significantly higher than those of genetically discordant strains, with the prevalence of eight VF genes being significantly higher in genetically identical E. coli strains. No significant differences were found between the two groups regarding antimicrobial susceptibility and biofilm formation potential. This study showed that genetically identical E. coli bacteremia strains have more VF genes than genetically discordant strains in recurrent E. coli bacteremia.

IMPORTANCEEscherichia coli causes bloodstream infection, although not all strains are pathogenic to humans. In some cases, this infection reoccurs, and several reports have described the clinical characteristics and/or molecular microbiology of recurrent Escherichia coli bacteremia. However, these studies focused on patients with specific characteristics, and they included cases caused by microorganisms other than Escherichia coli. Hence, little is known about the pathogenicity of Escherichia coli isolated from the recurrent one. The significance of our study is in evaluating the largest cohorts to date, as no cohort studies have been conducted on this topic.

A longitudinal population-based study of predictors of mortality from bloodstream infections in Calgary, Alberta, Canada

Aim: To study the predictors of mortality from nine major pathogens causing approximately 70% of cases over a 7-year period. Materials & methods: A population-based surveillance cohort of all adult and pediatric patients in the Calgary Zone with an initial episode of bloodstream infections (BSI). Results: The 1-year mortality was 29.2% among 9524 patients (5164 males [54%]). Incidence rates for BSI increased annually to 119.7/100,000 persons by 2016. Distinct survival curves were found for each specific pathogen. Age, comorbidity burden and infecting organism were significantly associated with increased hazard of death. No relationship occurred between the time to positivity for blood cultures and overall mortality. Conclusion: BSI has a high mortality, but overall survival depends on underlying host health and the type of pathogen acquired.

Risk factors for functional decline among survivors of Gram-negative bloodstream infection: A prospective cohort study

OBJECTIVE

To identify risk factors for functional decline after hospitalization for Gram-negative bacteremia.

PATIENTS AND METHODS

A prospective cohort study based on a randomized controlled trial conducted between January 1, 2013 and August 31, 2017 in Israel and Italy. Hospitalized patients with Gram-negative bacteremia who survived until day 90 and were not bedridden at baseline were included. The primary end point was functional decline at 90 days.

RESULTS

Five hundred and nine patients were included. The median age of the cohort was 71 years (interquartile range [IQR], 60-80 years), 46.4% (236/509) were male and 352 of 509 (69%) patients were independent at baseline. Functional decline at 90 days occurred in 24.4% of patients (124/509). In multivariable analysis; older age (odds ratio [OR], 1.03; for an one-year increment, 95% confidence interval [CI] 1.01-1.05), functional dependence in instrumental activities of daily living at baseline (OR, 4.64; 95% CI 2.5-8.6), low Norton score (OR, 0.87; 95% CI 0.79-0.96) and underlying comorbidities: cancer (OR, 2.01; 95% CI 1.14-3.55) and chronic pulmonary disease (OR, 2.23 95% CI 1.12-4.42) and longer length of hospital stay (OR 1.09; for one-day increment, 95% CI 1.04-1.15) were associated with functional decline. Appropriate empirical antibiotic treatment was associated with lower rates of functional decline within 90 days (OR, 0.4; 95% CI 0.21-0.78).

CONCLUSIONS

Patients surviving bloodstream infections have poor long term trajectories after clinical recovery and hospital discharge. This has vast implications for patients, their family members and health policy makers.

Escherichia coli bloodstream infections in the western interior of British Columbia, Canada: a population-based cohort study

Our population-based study objectives were to describe characteristics and outcomes of Escherichia coli bloodstream infections (BSIs), and to evaluate factors associated with outcomes. We included incident E. coli BSIs from western interior residents (British Columbia, Canada; 04/2010–03/2020). We obtained data including patient demographics, location of onset, infection focus, Charlson comorbidity index (CCI), antimicrobial resistance, 30-day all-cause mortality and length of hospital stay (LOS). Using multivariable logistic regression models fitted with generalised estimating equations, we estimated factors associated with 30-day mortality and long post-infection LOS (>75th percentile). We identified 1080 incident E. coli BSIs in 1009 patients. The crude incidence and 30-day mortality rates were 59.1 BSIs and 6.8 deaths/100 000 person-years, respectively. The 30-day case fatality risk was 11.5%. Compared to community-acquired E. coli BSIs, either healthcare-associated or nosocomial cases had higher odds of 30-day mortality. Older cases, non-urogenital BSI foci and CCI ⩾ 3 had higher odds of 30-day mortality compared to younger cases, urogenital foci and CCI < 3. In patients that survived to discharge, those with extended-spectrum β-lactamase (ESBL)-producing E. coli BSIs, nosocomial BSIs, and CCI ⩾ 3 had higher odds of long post-infection LOS compared to those with non-ESBL-producing, community-acquired and healthcare-associated, and CCI < 3. There is a substantial disease burden from E. coli BSIs.

Decrease in All-Cause 30-Day Mortality after Bacteraemia over a 15-Year Period: A Population-Based Cohort Study in Denmark in 2000-2014

INTRODUCTION

Bacteraemia is a frequent infectious condition that strongly affects morbidity and mortality. The incidence is increasing worldwide. This study explores all-cause 30-day mortality after bacteraemia in two out of Denmark's five healthcare regions with approximately 2.4 million inhabitants.

METHODS

Clinically significant bacteraemia episodes (n = 55,257) were identified from a geographically well-defined background population between 2000 and 2014, drawing on population-based data regarding bacterial species and vital status. All-cause 30-day mortality was assessed in relation to bacteraemia episodes, number of patients with analysed blood cultures and the background population.

RESULTS

We observed a decreasing trend of all-cause 30-day mortality between 2000 and 2014, both in relation to the number of bacteraemia episodes and the background population. Mortality decreased from 22.7% of the bacteraemia episodes in 2000 to 17.4% in 2014 (annual IRR [95% CI]: 0.983 [0.979-0.987]). In relation to the background population, there were 41 deaths per 100,000 inhabitants in 2000, decreasing to 39 in 2014 (annual IRR [95% CI]: 0.988 [0.982-0.993]). Numbers of inhabitants, bacteraemia episodes, and analysed persons having BCs increased during the period.

CONCLUSIONS

All-cause 30-day mortality in patients with bacteraemia decreased significantly over a 15-year period.

Recent Advances and a Roadmap to Aptamer-Based Sensors for Bloodstream Infections

The present review is intended to describe bloodstream infections (BSIs), the major pathogens responsible for BSIs, conventional tests and their limitations, commercially available methods used, and the aptamer and nanomaterials-based approaches developed so far for the detection of BSIs. The advantages associated with aptamers and the aptamer-based sensors, the comparison between the aptamers and the antibodies, and the various types of aptasensors developed so far for the detection of bloodstream infections have been described in detail in the present review. Also, the future outlook and roadmap toward aptamer-based sensors and the challenges associated with the aptamer development have also been concluded in this review.

Revisiting the epidemiology of bloodstream infections and healthcare-associated episodes: results from a multicentre prospective cohort in Spain (PRO-BAC Study)

The epidemiology of bloodstream infections (BSIs) is dynamic as it depends on microbiological, host and healthcare system factors. The aim of this study was to update the information regarding the epidemiology of BSIs in Spain considering the type of acquisition. An observational, prospective cohort study in 26 Spanish hospitals from October 2016 through March 2017 including all episodes of BSI in adults was performed. Bivariate analyses stratified by type of acquisition were performed. Multivariate analyses were performed by logistic regression. Overall, 6345 BSI episodes were included; 2510 (39.8%) were community-acquired (CA), 1661 (26.3%) were healthcare-associated (HCA) and 2056 (32.6%) hospital-acquired (HA). The 30-day mortality rates were 11.6%, 19.5% and 22.0%, respectively. The median age of patients was 71 years (interquartile range 60-81 years) and 3656 (58.3%; 95% confidence interval 57.1-59.6%) occurred in males. The proportions according to patient sex varied according to age strata. Escherichia coli (43.8%), Klebsiella spp. (8.9%), Staphylococcus aureus (8.9%) and coagulase-negative staphylococci (7.4%) were the most frequent pathogens. Multivariate analyses confirmed important differences between CA and HCA episodes, but also between HCA and HA episodes, in demographics, underlying conditions and aetiology. In conclusion, we have updated the epidemiological information regarding patients' profiles, underlying conditions, frequency of acquisition types and aetiological agents of BSI in Spain. HCA is confirmed as a distinct type of acquisition.

Burden of bloodstream infection in an area of Mid-Norway 2002-2013: a prospective population-based observational study

BACKGROUND

Studies from several countries indicate that the incidence and mortality of bloodstream infection (BSI) have been increasing over time.

METHODS

We studied the burden of disease and death related to BSI in a defined geographical area of Mid-Norway, where BSI episodes were prospectively recorded by the same microbiological department during 12 consecutive years. Death from BSI was defined as death within 30 days of BSI detection. Age and sex standardized incidence and mortality rates and case fatality rates were calculated.

RESULTS

Between 2002 and 2013, 1995 episodes of BSI in 1719 patients aged 16 to 99 years were included. The overall incidence of BSI was 215 per 100,000 person-years. The incidence increased exponentially with age, particularly in males. The incidence increased from 205 to 223 per 100,000 person-years from 2002-07 to 2008-13. Escherichia coli was the most frequently isolated infective agent, followed by Streptococcus pneumoniae and Staphylococcus aureus. The rate of S. pneumoniae BSI decreased over time in males (on average by 9.2% annually), but not in females. The total rate of BSI microbes with acquired resistance increased slightly over time, but did not exceed 2 episodes per 100,000 person-years. The mortality of BSI was 32 per 100,000 person-years, higher in males than in females (36 vs. 28 per 100,000 person-years) and was significantly higher in old age, particularly in males. The total BSI mortality was similar in the first and second halves of the study period, but the mortality of S. pneumoniae BSI decreased in males (15.0% annually). The crude case fatality decreased from the first to the second half of the study period (17.2% to 13.1%; p = 0.014). The rate of blood culture sampling increased more than twofold during the study period.

CONCLUSIONS

The mortality of BSI remained stable during 2002-2013. At the same time, BSI incidence increased and case fatality rate decreased, perhaps because an increased rate of blood culture sampling may have led to improved detection of milder BSI episodes. Very low, yet slightly increasing rates of microbes with acquired resistance were observed.

14-Year Survey in a Swedish County Reveals a Pronounced Increase in Bloodstream Infections (BSI). Comorbidity - An Independent Risk Factor for Both BSI and Mortality

OBJECTIVES

we assessed the incidence, risk factors and outcome of BSI over a 14-year period (2000-2013) in a Swedish county.

METHODS

retrospective cohort study on culture confirmed BSI among patients in the county of Östergötland, Sweden, with approximately 440,000 inhabitants. A BSI was defined as either community-onset BSI (CO-BSI) or hospital-acquired BSI (HA-BSI).

RESULTS

of a total of 11,480 BSIs, 67% were CO-BSI and 33% HA-BSI. The incidence of BSI increased by 64% from 945 to 1,546 per 100,000 hospital admissions per year during the study period. The most prominent increase, 83% was observed within the CO-BSI cohort whilst HA-BSI increased by 32%. Prescriptions of antibiotics in outpatient care decreased with 24% from 422 to 322 prescriptions dispensed/1,000 inhabitants/year, whereas antibiotics prescribed in hospital increased by 67% (from 424 to 709 DDD per 1,000 days of care). The overall 30-day mortality for HA-BSIs was 17.2%, compared to 10.6% for CO-BSIs, with an average yearly increase per 100,000 hospital admissions of 2 and 5% respectively. The proportion of patients with one or more comorbidities, increased from 20.8 to 55.3%. In multivariate analyses, risk factors for mortality within 30 days were: HA-BSI (2.22); two or more comorbidities (1.89); single comorbidity (1.56); CO-BSI (1.21); male (1.05); and high age (1.04).

CONCLUSION

this survey revealed an alarming increase in the incidence of BSI over the 14-year study period. Interventions to decrease BSI in general should be considered together with robust antibiotic stewardship programmes to avoid both over- and underuse of antibiotics.

Risk and prognosis of bacteremia and fungemia among first-time kidney transplant recipients: a population-based cohort study

BACKGROUND

Bacterial infections are common complications in kidney transplant recipients (KTRs). Little is known about incidence rates of bacteremia and fungemia (BAF) in KTRs.

METHODS

In this population-based cohort study, we used medical and administrative registries to identify episodes of BAF among KTRs in the Central Denmark and North Denmark Regions during 1995-2010. KTRs were followed from the date of their first transplantation to the earliest of BAF, graft loss, death, emigration or 31 December 2010. We calculated incidence rates of first BAF episode overall and stratified by time from transplantation. Potential risk factors were assessed using Cox regression analysis. The Kaplan-Meier analysis was used to estimate 30- and 90-day mortality.

RESULTS

Among 612 KTRs, we identified 138 first episodes of bacteremia during 2397 person-years of follow-up (PYFU). The overall incidence rate (IR) was 5.8 BAF episodes per 100 PYFU (95% confidence interval [CI]: 4.9-6.8). The incidence rate declined from 84.0 per 100 PYFU (95% CI: 61.6-114.5) during post-transplant day 0-30 to 2.3 per 100 PYFU (95% CI: 1.7-3.0) from post-transplant day 365 and onwards. Hospital-onset BAF comprised 39% of the episodes of BAF. The most frequently isolated microorganisms were Escherichia coli and Klebsiella species causing 49 (35.5%) and 29 (21.0%) episodes of BAF, respectively. The 30-day mortality was 2.1% (95% CI: 0.7-6.6).

CONCLUSIONS

While the risk of BAF in KTRs was high, thirty-day mortality was low. After the first post-transplant year, the IR of bacteremia was substantially lower than in the immediate post-transplant period.

The Thuringian registry for bloodstream infections, antibiotic resistance and the practice of blood culture sampling--AlertsNet

Evidence-based blood culture (BC) testing is of utmost importance for intensive care unit (ICU) patients suspected for sepsis. Knowledge of the aetiological agent and its susceptibility to anti-infective agents enables the clinician to initiate appropriate antimicrobial therapy and guides diagnostic procedures. This has been shown to reduce mortality, ICU stay and antibiotic overuse. Whereas microbiological laboratory practice has been highly standardised, shortfalls in pre-analytic procedures in the ICU have a significant effect on the diagnostic yield. Currently, surveillance data on BC practice lack hospital-, patient- and laboratory-based denominator data. Supporting information on differences in the clinical practice of BC testing, differences in the characteristics of the institution and the case-mix on specific wards, as well as differences in the availability of microbiological laboratories is demanded on a population basis. A population-based survey on BC practice has been established for the German Federal State of Thuringia connecting both hospitals and microbiological laboratories within an electronic registry for immediate enrolment of BC findings (AlertsNet; http://www.alertsnet.de). The registry includes microbiological results and clinical data as well as institutional variables (e.g. case severity indices) from all patients with clinically relevant positive BCs at the participating centres. The main objectives are to sustain and expand a population-based surveillance and warning system for the assessment of diagnosis, risk factors, treatment and outcomes of hospitalised patients and to improve outcomes of patients with bloodstream infections.

Early deaths in bloodstream infections: a population-based case series

A notable portion of deaths in bloodstream infections (BSI) have previously been shown to occur within 2 days after taking the first positive blood culture specimen. The aim of this study was to analyse patients' characteristics and causative pathogens of BSIs, leading to early deaths in order to explore possibilities for prevention. Patients with BSI in Helsinki and Uusimaa region (population = 1.5 million) in 2007 were identified from the National Infectious Disease Register (n = 2181) and their deaths within 2 days after the first positive blood culture from the Population Information System (n = 76). Of the early fatal BSIs, 42 (55%) were community-acquired (CA-BSI) and 34 (45%) healthcare-associated (HA-BSI). Charlson comorbidity index was moderate-to-high (index ≥ 3) in 71% of HA-BSIs and 60% of CA-BSIs. The most common pathogens in CA-BSIs were Streptococcus pneumoniae (29%) and Escherichia coli (24%) and in HA-BSIs Pseudomonas aeruginosa (24%) and Staphylococcus aureus (18%). The respiratory tract (50%) was the most common focus of infection. Empiric antimicrobial treatment was more often appropriate in CA-BSIs vs HA-BSIs (81% vs 41%, p < 0.001), but treatment delays were longer in CA-BSIs. The majority of the BSI patients who died early had severe comorbidities. S. pneumoniae accounted for one third of CA-BSIs, highlighting the potential role of pneumococcal vaccines in prevention. Early recognition of BSI and its origin (CA-BSI vs HA-BSI) is crucial. Continuous surveillance data on causative microbes and resistance trends in hospitals is needed to propose guidelines for empiric antimicrobial therapy of BSIs.

Bloodstream infections, antibiotic resistance and the practice of blood culture sampling in Germany: study design of a Thuringia-wide prospective population-based study (AlertsNet)

INTRODUCTION

Bloodstream infections are a major cause of death worldwide; blood culture (BC) sampling remains the most important tool for their diagnosis. Current data suggest that BC rates in German hospitals are considerably lower than recommended; this points to shortfalls in the application of microbiological analyses. Since early and appropriate BC diagnostics are associated with reduced case fatality rates and a shorter duration of antimicrobial therapy, a multicomponent study for the improvement of BC diagnostics was developed.

METHODS AND ANALYSIS

An electronic BC registry established for the German Federal state of Thuringia is the structural basis of this study. The registry includes individual patient data (microbiological results and clinical data) and institutional information for all clinically relevant positive BCs at the participating centres. First, classic result quality indicators for bloodstream infections (eg, sepsis rates) will be studied using Poisson regression models (adjusted for institutional characteristics) in order to derive relative ranks for feedback to clinical institutions. Second, a target value will be established for the process indicator BC rate. On the basis of this target value, recommendations will be made for a given combination of institutional characteristics as a reference for future use in quality control. An interventional study aiming at the improvement of BC rates will be conducted thereafter. On the basis of the results of a survey in the participating institutions, a targeted educational intervention will be developed. The success of the educational intervention will be measured by changes in the process indicator and the result indicators over time using a pre-post design.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics committee of the University Hospital Jena and from the Ethics committee of the State Chamber of Physicians of Thuringia. Findings of AlertsNet will be disseminated through public media releases and publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

DRKS00004825.

Neonatal Septicemia in Nepal: Early-Onset versus Late-Onset

Introduction. Neonatal septicemia is defined as infection in the first 28 days of life. Early-onset neonatal septicemia and late-onset neonatal septicemia are defined as illnesses appearing from birth to three days and from four to twenty-eight days postnatally, respectively. Methods. In this cross-sectional study, blood samples from the suspected infants were collected and processed in the bacteriology laboratory. The growth was identified by standard microbiological protocol and the antibiotic sensitivity testing was carried out by modified Kirby-Bauer disk diffusion method. Results. Among total suspected cases, the septicemia was confirmed in 116 (12.6%) neonates. Early-onset septicemia (EOS) was observed in 82 infants and late-onset septicemia (LOS) in 34 infants. Coagulase-negative staphylococcus (CoNS) (46.6%) was the predominant Gram-positive organism isolated from EOS as well as from LOS cases followed by Staphylococcus aureus (14.6%). Acinetobacter species (9.5%) was the predominant Gram-negative organism followed by Klebsiella pneumoniae (7.7%). Conclusions. The result of our study reveals that the CoNS, Staphylococcus aureus, Acinetobacter spp., and Klebsiella pneumoniae are the most common etiological agents of neonatal septicemia. In particular, since rate of CoNS causing sepsis is alarming, prompting concern to curb the excess burden of CoNS infection is necessary.

Population-based epidemiology and microbiology of community-onset bloodstream infections

Bloodstream infection (BSI) is a major cause of infectious disease morbidity and mortality worldwide. While a positive blood culture is mandatory for establishment of the presence of a BSI, there are a number of determinants that must be considered for establishment of this entity. Community-onset BSIs are those that occur in outpatients or are first identified <48 h after admission to hospital, and they may be subclassified further as health care associated, when they occur in patients with significant prior health care exposure, or community associated, in other cases. The most common causes of community-onset BSI include Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Antimicrobial-resistant organisms, including methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase/metallo-β-lactamase/carbapenemase-producing Enterobacteriaceae, have emerged as important etiologies of community-onset BSI.

Impact of Mandatory Public Reporting of Central Line-Associated Bloodstream Infections on Blood Culture and Antibiotic Utilization in Pediatric and Neonatal Intensive Care Units

BACKGROUND

As mandatory public reporting of healthcare-associated infections increases, there is concern that clinicians could attempt to decrease rates by avoiding the diagnosis of reportable infections.

OBJECTIVE

To determine whether blood culture and antibiotic utilization changed after mandatory public reporting of central line-associated bloodstream infection (CLABSI).

DESIGN

Interrupted time-series of blood culture and antibiotic rates before and after state-specific implementation of mandatory public reporting. We analyzed data from pediatric and neonatal intensive care units (ICUs) at 17 children's hospitals that contributed to the Pediatric Health Information System administrative database. We used multivariable regression with generalized linear mixed-effects models to determine adjusted rate ratios (ARRs) after implementation of mandatory public reporting. We conducted subgroup analysis on patients with central venous catheters. To assess temporal trends, we separately analyzed data from 4 pediatric hospitals in states without mandatory public reporting.

RESULTS

There was no significant effect of mandatory public reporting on rates of blood culture (pediatric ICU ARR, 1.03 [95% CI, 0.82-1.28]; neonatal ICU ARR, 1.06 [0.85-1.33]) or antibiotic utilization (pediatric ICU ARR, 0.86 [0.72-1.04]; neonatal ICU ARR, 1.09 [0.87-1.35]). Results were similar in the subgroup of patients with central venous catheter codes. Hospitals with and without mandatory public reporting experienced small decreases in blood culture and antibiotic use across the study period.

CONCLUSIONS

Mandatory public reporting of central line-associated bloodstream infection did not impact blood culture and antibiotic utilization, suggesting that clinicians have not shifted their practice in an attempt to detect fewer infections.

Decreasing incidence rates of bacteremia: a 9-year population-based study

BACKGROUND

Numerous studies have shown that the incidence rate of bacteremia has been increasing over time. However, few studies have distinguished between community-acquired, healthcare-associated and nosocomial bacteremia.

METHODS

We conducted a population-based study among adults with first-time bacteremia in Funen County, Denmark, during 2000-2008 (N = 7786). We reported mean and annual incidence rates (per 100,000 person-years), overall and by place of acquisition. Trends were estimated using a Poisson regression model.

RESULTS

The overall incidence rate was 215.7, including 99.0 for community-acquired, 50.0 for healthcare-associated and 66.7 for nosocomial bacteremia. During 2000-2008, the overall incidence rate decreased by 23.3% from 254.1 to 198.8 (3.3% annually, p < .001), the incidence rate of community-acquired bacteremia decreased by 25.6% from 119.0 to 93.8 (3.7% annually, p < .001) and the incidence rate of nosocomial bacteremia decreased by 28.9% from 82.2 to 56.0 (4.2% annually, p < .001). The incidence rate of healthcare-associated bacteremia remained stable. The most common microorganisms were Escherichia coli (28.3%), Staphylococcus aureus (12.3%), coagulase-negative staphylococci (10.0%) and Streptococcus pneumoniae (9.1%). Regardless of place of acquisition, the proportion of bacteremias caused by enterococci increased (p < .05) and the proportion caused by coagulase-negative staphylococci decreased (p < .05).

CONCLUSIONS

The incidence rates of community-acquired and nosocomial bacteremia decreased substantially over time.

Human and avian extraintestinal pathogenic Escherichia coli: infections, zoonotic risks, and antibiotic resistance trends

Extraintestinal pathogenic Escherichia coli (ExPEC) constitutes ongoing health concerns for women, newborns, elderly, and immunocompromised individuals due to increased numbers of urinary tract infections (UTIs), newborn meningitis, abdominal sepsis, and septicemia. E. coli remains the leading cause of UTIs, with recent investigations reporting the emergence of E. coli as the predominant cause of nosocomial and neonatal sepsis infections. This shift from the traditional Gram-positive bacterial causes of nosocomial and neonatal sepsis infections could be attributed to the use of intrapartum chemoprophylaxis against Gram-positive bacteria and the appearance of antibiotic (ATB) resistance in E. coli. While ExPEC strains cause significant healthcare concerns, these bacteria also infect chickens and cause the poultry industry economic losses due to costs of containment, mortality, and disposal of carcasses. To circumvent ExPEC-related costs, ATBs are commonly used in the poultry industry to prevent/treat microbial infections and promote growth and performance. In an unfortunate linkage, chicken products are suspected to be a source of foodborne ExPEC infections and ATB resistance in humans. Therefore, the emergence of multidrug resistance (MDR) (resistance to three or more classes of antimicrobial agents) among avian E. coli has created major economic and health concerns, affecting both human healthcare and poultry industries. Increased numbers of immunocompromised individuals, including the elderly, coupled with MDR among ExPEC strains, will continue to challenge the treatment of ExPEC infections and likely lead to increased treatment costs. With ongoing complications due to emerging ATB resistance, novel treatment strategies are necessary to control ExPEC infections. Recognizing and treating the zoonotic risk posed by ExPEC would greatly enhance food safety and positively impact human health.

Bacterial profile and antimicrobial susceptibility pattern in septicemia suspected patients attending Gondar University Hospital, Northwest Ethiopia

BACKGROUND

Bacterial blood stream infection constitutes a significant public health problem and it is an important cause of morbidity and mortality in hospitalized patients. The aim of this study was to assess the prevalence of bacterial isolates from septicemia suspected patients and their antimicrobial susceptibility pattern in Gondar University Hospital.

METHODS

This laboratory based retrospective study of 390 blood culture and susceptibility tests was conducted in Bacteriology Laboratory of the University of Gondar Teaching Hospital. The samples were collected and processed following standard microbiological techniques as part of the routine clinical management of the patient. Antibiotic susceptibility testing was done on pure culture isolates employing disc-diffusion method for the commonly used antibiotics. The data were analyzed by using SPSS version 16 and the results were summarized by using tables and graphs.

RESULTS

Out of 390 blood culture results, 71 (18.2%) were culture positive. The predominant bacteria isolated from blood culture were Coagulase negative staphylococci 30 (42.3%), followed by S. aureus 17 (23.9%) and Klebiesella spp 9 (12.9%), E. coli 5 (7.0%), Pseudomonas aeroginosa 4 (5.6%) and Salmonella spp. 3 (4.2%). The gram positive and gram negative bacteria constituted 49 (69%) and 22 (31%) of the culture isolates; respectively. The isolates showed high rates of resistance to most antibiotics tested. The range of resistance for Gram positive and Gram negative were from 23.5% - 58.8%, and 20%- 100% respectively.

CONCLUSIONS

In the present study most of the pathogens isolated from blood culture showed high rate of resistance to most commonly used antibiotics used to treat bacterial infections. Therefore, rational use of antibiotics should be practiced.

Update on bloodstream infections in ICUs

PURPOSE OF REVIEW

To describe new developments in the epidemiology and outcomes associated with bloodstream infections (BSIs) in ICUs.

RECENT FINDINGS

The incidence and outcomes associated with BSI among patients admitted to ICUs have been changing as a result of increasing numbers of older patients with comorbid medical illnesses suffering critical illness. Community-onset healthcare-associated BSIs are recognized as important causes of BSIs in ICUs and are distinct from community-acquired and nosocomial BSIs. Electronic surveillance systems are evolving that provide efficient information about the occurrence of BSIs and for tracking the emergence of resistance.

SUMMARY

The incidence of healthcare-associated BSIs increases and is associated with bacteria resistant to antimicrobials used in community-acquired infections. The recent years have witnessed the emergence of extensively resistant bacteria in many regions worldwide, and this is associated with major implications for failure of antimicrobial therapies. Enhanced preventive efforts and optimization of therapy are needed in order to reduce the major burden of BSIs in critically ill patients and to minimize the further emergence of resistance.

Defining the epidemiology of bloodstream infections: the 'gold standard' of population-based assessment

Bloodstream infections (BSIs) are a major cause of morbidity and mortality. Although population-based studies have been proposed as an optimal means to define their epidemiology, the merit of these designs has not been well documented. This report investigated the potential value of using population-based designs in defining the epidemiology of BSIs. Population-based BSI surveillance was conducted in Calgary, Canada (population 1.24 million) and illustrative comparisons were made between the overall and selected subgroup cohorts within five main themes. The value of population denominator data, and age and gender standardization for calculation and comparison of incidence rates were demonstrated. In addition, a number of biases including those related to differential admission rates, selected hospital admission, and referral bias were highlighted in non-population-based cohorts. Due to their comprehensive nature and intrinsic minimization of bias, population-based designs should be considered the gold standard means of defining the epidemiology of an infectious disease.

Trends in mortality from septicaemia and pneumonia with economic development: an age-period-cohort analysis

Background

Hong Kong population has experienced drastic changes in its economic development in the 1940s. Taking advantage of Hong Kong’s unique demographic and socioeconomic history, characterized by massive, punctuated migration waves from Southern China, and recent, rapid transition from a pre-industrialized society to the first ethnic Chinese community reaching “first world” status over the last 60 years (i.e., in two or three generations), we examined the longitudinal trends in infection related mortality including septicemia compared to trends in non-bacterial pneumonia to generate hypotheses for further testing in other recently transitioned economies and to provide generalized aetiological insights on how economic transition affects infection-related mortality.

Methods

We used deaths from septicemia and pneumonia not specified as bacterial, and population figures in Hong Kong from 1976–2005. We fitted age-period-cohort models to decompose septicemia and non-bacterial pneumonia mortality rates into age, period and cohort effects.

Results

Septicaemia-related deaths increased exponentially with age, with a downturn by period. The birth cohort curves had downward inflections in both sexes in the 1940s, with a steeper deceleration for women. Non-bacterial pneumonia-related deaths also increased exponentially with age, but the birth cohort patterns showed no downturns for those born in the 1940s.

Conclusion

The observed changes appeared to suggest that better early life conditions may enable better development of adaptive immunity, thus enhancing immunity against bacterial infections, with greater benefits for women than men. Given the interaction between the immune system and the gonadotropic axis, these observations are compatible with the hypothesis that upregulation of the gonadotropic axis underlies some of the changes in disease patterns with economic development.

The changing epidemiology of Staphylococcus aureus bloodstream infection: a multinational population-based surveillance study

Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance was conducted nationally in Finland and regionally in Canberra, Australia, western Sweden, and three areas in each of Canada and Denmark during 2000-2008. Incidence rates were age-standardized and gender-standardized to the EU 27-country 2007 population. During 83 million person-years of surveillance, 18,430 episodes of S. aureus BSI were identified. The overall annual incidence rate for S. aureus BSI was 26.1 per 100,000 population, and those for methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were 24.2 and 1.9 per 100,000, respectively. Although the overall incidence of community-onset MSSA BSI (15.0 per 100,000) was relatively similar across regions, the incidence rates of hospital-onset MSSA (9.2 per 100,000), community-onset MRSA (1.0 per 100,000) and hospital-onset MRSA (0.8 per 100,000) BSI varied substantially. Whereas the overall incidence of S. aureus BSI did not increase over the study period, there was an increase in the incidence of MRSA BSI. Major changes in the occurrence of community-onset and hospital-onset MSSA and MRSA BSI occurred, but these varied significantly among regions, even within the same country. Although major changes in the epidemiology of community-onset and hospital-onset MSSA and MRSA BSIs are occurring, this multinational population-based study did not find that the overall incidence of S. aureus BSI is increasing.

Population-based laboratory assessment of the burden of community-onset bloodstream infection in Victoria, Canada

Although community-onset bloodstream infection (BSI) is recognized as a major cause of morbidity and mortality, its epidemiology has not been well defined in non-selected populations. We conducted population-based laboratory surveillance in the Victoria area, Canada during 1998-2005 in order to determine the burden associated with community-onset BSI. A total of 2785 episodes were identified for an overall annual incidence of 101·2/100,000. Males and the very young and the elderly were at highest risk. Overall 1980 (71%) episodes resulted in hospital admission for a median length of stay of 8 days; the total days of acute hospitalization associated with community-onset BSI was 28 442 days or 1034 days/100,000 population per year. The in-hospital case-fatality rate was 13%. Community-onset BSI is associated with a major burden of illness. These data support ongoing and future preventative and research efforts aimed at reducing the major impact of these infections.

Influence of referral bias on the clinical characteristics of patients with Gram-negative bloodstream infection

Referral bias can influence the results of studies performed at tertiary-care centres. In this study, we evaluated demographic and microbiological factors that influenced referral of patients with Gram-negative bloodstream infection (BSI). We identified 2919 and 846 unique patients with Gram-negative BSI in a referral cohort of patients treated at Mayo Clinic Hospitals and a population-based cohort of Olmsted County, Minnesota, residents between 1 January 1998 and 31 December 2007, respectively. Multivariable logistic regression analysis was used to determine factors associated with referral. Elderly patients aged ≥80 years with Gram-negative BSI were less likely to be referred than younger patients [odds ratio (OR) 0·43, 95% confidence intervals (CI) 0·30-0·62] as were females (OR 0·63, 95% CI 0·53-0·74). After adjusting for age and gender, bloodstream isolates of Escherichia coli (OR 0·50, 95% CI 0·43-0·58) and Proteus mirabilis (OR 0·49, 95% CI 0·30-0·82) were underrepresented in the referral cohort; and Pseudomonas aeruginosa (OR 2·26, 95% CI 1·70-3·06), Enterobacter cloacae (OR 2·31, 95% CI 1·53-3·66), Serratia marcescens (OR 2·34, 95% CI 1·33-4·52) and Stenotrophomonas maltophilia (OR 17·94, 95% CI 3·98-314·43) were overrepresented in the referral cohort. We demonstrated that demographic and microbiological characteristics of patients with Gram-negative BSI had an influence on referral patterns. These factors should be considered when interpreting results of investigations performed at tertiary-care centres.

Existing data sources for clinical epidemiology: The North Denmark Bacteremia Research Database

Bacteremia is associated with high morbidity and mortality. Improving prevention and treatment requires better knowledge of the disease and its prognosis. However, in order to study the entire spectrum of bacteremia patients, we need valid sources of information, prospective data collection, and complete follow-up. In North Denmark Region, all patients diagnosed with bacteremia have been registered in a population-based database since 1981. The information has been recorded prospectively since 1992 and the main variables are: the patient’s unique civil registration number, date of sampling the first positive blood culture, date of admission, clinical department, date of notification of growth, place of acquisition, focus of infection, microbiological species, antibiogram, and empirical antimicrobial treatment. During the time from 1981 to 2008, information on 22,556 cases of bacteremia has been recorded. The civil registration number makes it possible to link the database to other medical databases and thereby build large cohorts with detailed longitudinal data that include hospital histories since 1977, comorbidity data, and complete follow-up of survival. The database is suited for epidemiological research and, presently, approximately 60 studies have been published. Other Danish departments of clinical microbiology have recently started to record the same information and a population base of 2.3 million will be available for future studies.

Changes in blood culture methodology have an impact on time trends of bacteraemia: a 26-year regional study

The incidence of bacteraemia has increased considerably during the last decades. This may be related to population ageing, increased use of invasive procedures, and increased ascertainment of bacteraemia. Generalized additive and generalized linear models were used to analyse the impact of four successive improvements in blood culture methodology on the recovery of prevalent blood culture isolates while simultaneously controlling for underlying time trend and seasonal variation. Between 1981 and 2006, 20 091 bacteraemias comprising 22 800 blood culture isolates were diagnosed. The changes in methodology increased the recovery of some bacterial groups; the greatest impact was observed for Enterobacteriaceae, pneumococci andStaphylococcus aureuswhereas recovery of β-haemolytic streptococci,Pseudomonas aeruginosa, other Gram-negative aerobes, and fungi was not affected. Changes in blood culture methodology should be taken into account when assessing time trends of bacteraemia.

Salmonella enterica bacteraemia: a multi-national population-based cohort study

Background

Salmonella enterica is an important emerging cause of invasive infections worldwide. However, population-based data are limited. The objective of this study was to define the occurrence of S. enterica bacteremia in a large international population and to evaluate temporal and regional differences.

Methods

We conducted population-based laboratory surveillance for all salmonella bacteremias in six regions (annual population at risk 7.7 million residents) in Finland, Australia, Denmark, and Canada during 2000-2007.

Results

A total of 622 cases were identified for an annual incidence of 1.02 per 100,000 population. The incidence of typhoidal (serotypes Typhi and Paratyphi) and non-typhoidal (other serotypes) disease was 0.21 and 0.81 per 100,000/year. There was major regional and moderate seasonal and year to year variability with an increased incidence observed in the latter years of the study related principally to increasing rates of non-typhoidal salmonella bacteremias. Advancing age and male gender were significant risk factors for acquiring non-typhoidal salmonella bacteremia. In contrast, typhoidal salmonella bacteremia showed a decreasing incidence with advancing age and no gender-related excess risk.

Conclusions

Salmonella enterica is an important emerging pathogen and regional determinants of risk merits further investigation.

Rationale for and protocol of a multi-national population-based bacteremia surveillance collaborative

BACKGROUND

Bloodstream infections are frequent causes of human illness and cause major morbidity and death. In order to best define the epidemiology of these infections and to track changes in occurrence, adverse outcome, and resistance rates over time, population based methodologies are optimal. However, few population-based surveillance systems exist worldwide, and because of differences in methodology inter-regional comparisons are limited. In this report we describe the rationale and propose first practical steps for developing an international collaborative approach to the epidemiologic study and surveillance for bacteremia.

FINDINGS

The founding collaborative participants represent six regions in four countries in three continents with a combined annual surveillance population of more than 8 million residents.

CONCLUSION

Future studies from this collaborative should lead to a better understanding of the epidemiology of bloodstream infections.

The changing burden of pediatric bloodstream infections in Calgary, Canada, 2000-2006

BACKGROUND

The epidemiology of pediatric bloodstream infection has not been well defined in general populations. The primary objective of this study was to describe the burden of illness of pediatric bloodstream infections in a large Canadian region and secondarily to assess the effect of implementation of universal infant immunization with 7-valent pneumococcal conjugate vaccine (PCV7) in 2002.

METHODS

Surveillance for all bloodstream infections was conducted among pediatric (<18 years) residents of the Calgary Health Region during 2000-2006.

RESULTS

Nine hundred ninety-five episodes of bloodstream infection occurred for an overall annual incidence of 53.7 per 100,000. Forty-eight percent were community-acquired, 27% were nosocomial-acquired, and 26% were healthcare-associated community onset. The risk for bloodstream infection was highest in neonates. The annual incidence of bloodstream infection changed significantly (P < 0.001) and was attributed to a decreasing incidence of community (P = 0.001) acquired disease. The most common species isolated were Streptococcus pneumoniae, Staphylococcus aureus, and Escherichia coli. Overall rates of pneumococcal infection decreased significantly in the post-PCV7 era (2004-2006) as compared with pre-PCV7 era (2000-2001) (4.6 vs. 13.6 per 100,000; P < 0.0001). This was even more pronounced in the subset with community-acquired disease (3.0 vs. 11.3 per 100,000; P < 0.0001) especially in the age group between 1 and 23 months of age (7.3 vs. 58.9 per 100,000; P < 0.0001). The overall mortality rate was 2 per 100,000/yr.

CONCLUSIONS

Bloodstream infections are an important cause of disease in children. Implementation of PCV7 has been associated with a significant reduction in the overall burden of disease.

Incidence, risk factors and outcomes of Escherichia coli bloodstream infections in a large Canadian region

Although Escherichia coli is the most common cause of bloodstream infection, its epidemiology has not been well defined in non-selected populations. We sought to describe the incidence of risk factors for, and outcomes associated with, E. coli bacteraemia. Population-based surveillance for E. coli bacteraemia was conducted in the Calgary Health Region (population 1.2 million) during the period 2000-2006. In total, 2368 episodes of E. coli bacteraemia were identified for an overall annual population incidence of 30.3/100 000; 15% were nosocomial, 32% were healthcare-associated community-onset and 53% were community-acquired bacteraemias. The very young and the elderly were at highest risk for E. coli bacteraemia. Sixty per cent of the episodes occurred in females (relative risk 1.5; 95% CI 1.4-1.6). Dialysis, solid organ transplantation and neoplastic disease were the most important risk factors for acquiring E. coli bacteraemia. Rates of resistance to ampicillin, trimethoprim-sulphamethoxazole, gentamicin, ciprofloxacin, cefazolin and ceftriaxone increased significantly during the period 2000-2006. The case-fatality rate was 11% and the annual population mortality rate was 2.9/100 000. Increasing age, ciprofloxacin resistance, non-urinary focus and a number of comorbid illnesses were independently associated with an increased risk of death, and community acquisition and urinary focus were associated with a lower risk of death. This study documents the major burden of illness associated with E. coli bacteraemia and identifies groups at increased risk for acquiring and dying from these infections. The emergence of ciprofloxacin resistance and its adverse effect on patient outcome is a major concern.

Development, impact and outcomes of the Hull Bacteraemia Service

BACKGROUND

Bacteraemia is a significant cause of mortality and healthcare expenditure. Evidence suggests that consultation by an infection specialist may improve outcomes.

AIM

To review the characteristics and outcomes of patients seen by a newly implemented bacteraemia service.

METHODS

Retrospective review of data collected at time of consultation. Economic analyses and benchmarking of outcomes were also performed.

RESULTS

One hundred and fifty-one patients were seen by the service over an 18-month period. Staphylococcus aureus was the most common isolate and central venous lines the most common source. Antibiotics were changed and additional investigations suggested in 62% and 61% of patients, respectively. The 30-day mortality was 19%. Implementation and delivery of the service over the 18-month study period cost pound 22,663 (pound 15,109 per year). The cost per change in antibiotic prescription was pound 244. The cost per 'near-miss' detected was pound 1193. Overall mortality was no higher and possibly lower than in published studies.

CONCLUSION

We believe that this model of care may be suitable for the management of patients with bacteraemia. A study assessing the cost-effectiveness of this approach is required.

Increase in bloodstream infections in Finland, 1995-2002

A national, population-based laboratory surveillance of bloodstream infections (BSI) in Finland was performed. Blood-culturing rates were determined from data from clinical microbiology laboratories and trends in rates were evaluated using Poisson regression. During 1995-2002, 51,510 cases of BSI were notified; the annual incidence increased from 104 to 145 cases/100,000 (40%). Rates increased in all age groups but persons aged >or= 75 years accounted for 28% of cases and showed the largest rate increase. Escherichia coli, coagulase-negative staphylococci, Staphylococcus aureus and Streptococcus pneumoniae accounted for 58% of isolates and their relative proportions were unchanged over time. The annual blood-culturing rate increased by one-third during the study period but the number of BSI detected per blood cultures remained unchanged. Regional BSI incidence was significantly associated with blood-culturing rates. We conclude that the increase in BSI rates may have been due to more frequent blood culturing but was not associated with changes in the reporting system or aetiology of BSI.

Burden of community-onset bloodstream infection: a population-based assessment

Although community-onset bloodstream infection (BSI) is recognized to be a major cause of morbidity and mortality, there is a paucity of population-based studies defining its overall burden. We conducted population-based laboratory surveillance for all community-onset BSI in the Calgary Health Region during 2000-2004. A total of 4467 episodes of community-onset BSI were identified for an overall annual incidence of 81.6/100,000. The three species, Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae were responsible for the majority of community-onset BSI; they occurred at annual rates of 25.8, 13.5, and 10.1/100,000, respectively. Overall 3445/4467 (77%) episodes resulted in hospital admission representing 0.7% of all admissions to major acute care hospitals. The subsequent hospital length of stay was a median of 9 (interquartile range, 5-15) days; the total days of acute hospitalization attributable to community-onset BSI was 51,146 days or 934 days/100,000 annually. Four hundred and sixty patients died in hospital for a case-fatality rate of 13%. Community-onset BSI is common and has a major patient and societal impact. These data support further efforts to reduce the burden of community-onset BSI.

Secular trends of blood isolates in patients from a rural area population hospitalized in a tertiary center in a small city in Greece

BACKGROUND

Most of the studies evaluating the secular trends of blood isolates come from tertiary hospitals in urban areas. We sought to study the trends of the antimicrobial resistance of blood isolates in patients from a rural population hospitalized in a tertiary hospital in a small city in Greece.

METHODS

We retrospectively collected and analysed data for the first positive blood culture obtained for each admission for each patient hospitalized in General Hospital of Tripolis, Tripolis, Peloponnesus, Greece during a 5 year period (16/05/2000-15/05/2005).

RESULTS

Sixty-seven thousand and seventy patients were hospitalized during the study period from whom 3,206 blood cultures were obtained. A higher increase of the number of obtained blood cultures than the number of admissions was noted during the study period (p < 0.001). Three hundred and seventy-three (11.6%) blood cultures were positive. Coagulase-negative staphylococci (35.9%), Escherichia coli (29%), and Staphylococcus aureus (18.2%) were the most commonly isolated pathogens. Among the Staphylococcus aureus isolates, the proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 17.2% (5/29). The proportion of Escherichia coli resistant to trimethoprim and sulfamethoxazole, ampicillin and cefuroxime was 29.6% (32/108), 25.0% (27/108), and 8.3% (9/108) respectively. Imipenem-resistance was noted in 3.4% (1/29) of Pseudomonas aeruginosa isolates. There were only 6 (1.6%) Acinetobacter baummanii blood isolates during the study period.

CONCLUSION

The antimicrobial resistance of isolates from patients receiving care at the studied tertiary hospital in a small city in Greece is considerably less compared to that noted in tertiary hospitals in larger cities of the country.

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.

Source of infection and other factors associated with case fatality in community-acquired bacteremia—a Danish population-based cohort study from 1992 to 1997

OBJECTIVE

To examine the association between the source of infection, other factors and the 30-day case-fatality rate (CFR) in patients with community-acquired bacteremia.

METHODS

We included in the study 1844 patients older than 15 years (median age 72 years) with a first episode of community-acquired bacteremia in the period 1992-97 from a population-based bacteremia database. Information on co-morbidity, antibiotic prescriptions and date of death was obtained from health registries through linkage with the patient's personal identification number. The outcome measure was the overall CFR.

RESULTS

The mean CFR was 18% (20% in 1992-95, 15% in 1996-97). The commonest sources of infection were the urinary tract (29%) and the respiratory tract (20%); patients with an undetermined source accounted for 21% in 1992-95 and 13% in 1996-97. The most frequent bacteria were Escherichia coli (33%) and Streptococcus pneumoniae (22%). Thirty-two per cent of patients did not receive appropriate empirical antibiotic therapy. The following factors were associated with CFR: source of infection other than the urinary tract, first four years of the study, age >/=75 years, and presence of co-morbidity. An undetermined source showed the strongest association with CFR during the period 1996-97.

CONCLUSIONS

As an undetermined source of infection was strongly associated with CFR, physicians should be aware of the significance of identifying and eliminating a source of infection, and more efforts should be directed at timely and appropriate empirical antibiotic therapy.

Incidence and short-term prognosis of infective endocarditis in Denmark, 1980-1997

Infective endocarditis is a serious bacterial infection, but there are relatively few data about its occurrence and prognosis. The incidence rate, 30-d case fatality and mortality rate of infective endocarditis were estimated in this registry-based cohort study. The Danish National Registry of Patients was used to estimate national incidence rates, and information on the date of death was obtained through linkage to the Civil Registration System. The study included 3351 patients with infective endocarditis from 1980 to 1997. The incidence rate for men increased from 4 to 6 per 100,000 person-years, and for women from 3 to 4 per 100,000 person-years. The mean incidence rate varied from 1.5 per 100,000 person-years in women younger than 50 y to 15.5 in men older than 70 y. The incidence increased in most age groups but was most pronounced in younger men. The overall 30-d case fatality rate of 23% increased with age and decreased with calendar time. The mean mortality rate was 0.94 per 100,000 y and decreased in the study period in most age groups. There was an increasing incidence of infective endocarditis and an improvement in the prognosis.

Neisseria meningitidis phenotypic markers and septicaemia, disease progress and case-fatality rate of meningococcal disease: a 20-year population-based historical follow-up study in a Danish county

The incidence rate (IR) and case-fatality rate (CFR) of meningococcal disease increased during the late 1980s and early 1990s in North Jutland County, Denmark. We examined the hypothesis that phenotypic markers of Neisseria meningitidis are predictors of septicaemia with or without meningitis, rapid disease progress and fatal outcome of meningococcal disease and we studied whether changes in IR and CFR over time might be related to emergence or spread of certain phenotypes. This follow-up study was based on a complete registration of 413 cases of meningococcal disease in North Jutland County during 1980-99. Phenotypic markers included serogroup, serotype and serosubtype. A complete phenotype was available for 315 cases (76 %); 100 (32 %) strains were phenotype B : 15 : P1.7,16 and 31 (10 %) were C : 2a : P1.2,5. Septicaemia without meningitis was less common in cases with B : 15 : P1.7,16 and C : 2a : P1.2,5 strains. No association was found between phenotype and rapid disease progress. The overall CFR was 12 %. An increased CFR was associated with phenotypes B : 15 : P1.7,16 [odds ratio (OR) 2.8, 95 % confidence interval (CI) 1.2-18.5] and C : 2a : P1.2,5 (OR 5.2, 95 % CI 1.6-16.4) when compared with other phenotypes. The prevalence of B : 15 : P1.7,16 strains increased gradually during the study period and the CFR increased from 8 % during 1980-89 to 19 % during 1990-99, although the CFR for other phenotypes also increased. The CFR for C : 2a : P1.2,5 remained high ( approximately 20 %), but the contribution of this phenotype to the overall CFR decreased during the study period. In conclusion, phenotypes B : 15 : P1.7,16 and C : 2a : P1.2,5 were predictors of an increased CFR. The high prevalence of phenotype B : 15 : P1.7,16 contributed to increased overall IR and CFR during 1990-99.