Search

Objectives: Studies examining time to positivity (TTP) of blood cultures as a risk factor for death have shown conflicting results. The study objective was to examine the effect of TTP on all-cause-30-day case-fatality among a population-based cohort of patients with bloodstream infections (BSI)., Methods: A retrospective cohort study including all residents of Queensland, Australia with incident monomicrobial BSI managed in the publicly funded healthcare system from 2000 to 2019 was performed. Clinical, TTP and all-cause 30-day case-fatality information was obtained from state-wide sources., Results: A cohort of 88 314 patients was assembled. The median TTP was 14 hours, with 5th, 25th, 75th, and 95th percentiles of 4, 10, 20, and 53 hours, respectively. The TTP varied significantly by BSI aetiology. The 30-day all-cause case-fatality rate was 2606/17 879 (14.6%), 2834/24 272 (11.7%), 2378/20 359 (11.7%), and 2752/22 431 (12.3%) within the first, second, third, and fourth TTP quartiles, respectively (p < 0.0001). After adjustment for age, sex, onset, comorbidity, and focus of infection, TTP within 10 hours (first quartile) was associated with a significantly increased risk for death (odds ratio 1.43; 95% CI, 1.35-1.50; p < 0.001). After adjustment for confounding variables (odds ratio; 95% CI), TTP within the first quartile for Staphylococcus aureus (1.56; 1.41-1.73), Streptococcus pneumoniae (1.91; 1.49-2.46), β-hemolytic streptococci (1.23; 1.00-1.50), Pseudomonas species (2.23; 1.85-2.69), Escherichia coli (1.37; 1.23-1.53), Enterobacterales (1.38; 1.16-1.63), other Gram-negatives (1.68; 1.36-2.06), and anaerobes (1.58; 1.28-1.94) increased the risk for case-fatality., Discussion: This population-based analysis provides evidence that TTP is an important determinant of mortality among patients with BSI., (Copyright © 2024 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: The objective of this systematic review and meta-analysis was to estimate the global prevalence of multi-drug resistant (MDR) Pseudomonas aeruginosa causing ventilator-associated pneumonia (VAP)., Methods: The systematic search was conducted in four databases. Original studies describing MDR P. aeruginosa VAP prevalence in adults from 2012- 2022 were included. A meta-analysis, using the random effects model, was conducted for overall, subgroups (country, published year, study duration, and study design), and European data, respectively. Univariate meta-regression based on pooled estimates was also conducted. Systematic review registered in International Prospective Register of Systematic Review (CRD42022384035)., Results: In total of 31 studies, containing a total of 7951 cases from 16 countries, were included. The overall pooled prevalence of MDR among P. aeruginosa causing VAP was 33% (95% confidence interval [CI] 27.7-38.3%). The highest prevalence was for Iran at 87.5% (95% CI 69-95.7%), and the lowest was for the USA at 19.7% (95% CI 18.6-20.7%). The European prevalence was 29.9% (95% CI 23.2-36.7%)., Conclusions: This review indicates that the prevalence of MDR P. aeruginosa in patients with VAP is generally high and varies significantly between countries; however, data are insufficient for many countries. The data in this study can provide a reference for VAP management and drug customisation strategies., Competing Interests: Declarations of competing interest The authors have no competing interests to declare., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objectives: This population-based study aimed to investigate the risk factors and effect of extended-spectrum beta-lactamase (ESBL) production on clinical outcomes in Escherichia coli bloodstream infection (BSI) patients., Methods: The study population was defined as patients aged ≥15 years with E. coli BSI in Queensland, Australia, from 2000 to 2019. Outcomes were defined as 30-day case fatality, hospital length of stay (LOS), and recurrent E. coli BSI., Results: A total of 27,796 E. coli BSIs were identified, of which 1112 (4.0%) were ESBL-producers. Patients with ESBL-Ec BSI were more frequently older, male, with comorbidity, recurrent E. coli BSI, and less likely with community-associated community-onset infections as compared to non-ESBL-Ec BSI patients. The standardized mortality rate of ESBL-Ec BSI increased 8-fold from 2000 to 2019 (1 to 8 per million residents) and case fatality was 12.8% (n = 142) at 30 days from positive blood culture. Patients with ESBL-Ec BSI were not at higher risk of 30-day case fatality (adjusted hazard ratio [HR] = 0.98, 95% CI: 0.83-1.17), but had higher risk of recurring episodes (adjusted subdistribution HR = 1.58, 95% CI: 1.29-1.92) and observed 14% longer LOS (adjusted incidence rate ratio = 1.14, 95% CI: 1.10-1.18) than non-ESBL-Ec BSI patients., Conclusion: In this large patient cohort, ESBL-Ec BSI did not increase case fatality risk but observed higher hospital LOS and recurrent E. coli BSI than non-ESBL-Ec BSI. Clinical resources are warranted to account for the higher morbidity risk associated with ESBL production and incidence., Competing Interests: Declarations of competing interest DLP has received research grants from Merck, Pfizer, bioMerieux, and Shionogi outside of the submitted work. He has also received personal fees from AMR Action Fund, Merck, Pfizer, Shionogi, Spero, Lysovant, The Medicines Company, Entasis, VenatoRx, QPex, bioMerieux, and Accelerate, and is conducting a study on E. coli vaccination sponsored by Janssen. PNAH has received research grants from Merck, Sharpe, and Dohme (MSD), Sandoz, and Shionogi Ltd, outside of the submitted work, and has served on advisory boards for OpGen, Merck, and Sandoz and received speakers fees from Pfizer, OpGen, and Sandoz paid to the University of Queensland. The remaining authors have no competing interests to declare., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Small case series and reports suggest that Sphingomonas paucimobilis is predominantly a cause of nosocomial bloodstream infections (BSI) with very low associated mortality. Our objective was to describe the epidemiology and outcome of Sphingomonas species BSI in a large Australian population., Methods: We included all residents of Queensland, Australia, with BSI because of Sphingomonas species identified within the publicly funded system from 2000 to 2019., Results: A total of 282 incident episodes of Sphingomonas species BSI were identified for an age- and sex-adjusted incidence of 3.2 per million population annually. Incidence rates were highest in the tropical regions of the state. Most (94%) of the isolates were confirmed as Sphingomonas paucimobilis. In addition, 77% of the infections were community-onset, of which 48% were community-associated, and 30% were healthcare-associated. The very young, the old, and male patients were at the highest risk. Patients with community-associated disease were, on average, younger, had fewer co-morbidities, and were less likely to have polymicrobial infections. At least 1 co-morbidity was identified in 62% of patients, with malignancy, diabetes, and lung disease most prevalent. The overall all-cause 30-day case-fatality rate was 6%., Conclusion: Sphingomonas paucimobilis BSI is a predominantly community-onset disease associated with a significant risk of death., Competing Interests: Conflict of interest The authors declare they have no conflicts of interest., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Sepsis and bloodstream infection are associated with significant morbidity and mortality, and early effective antimicrobial therapy has been demonstrated to improve patient outcomes. Traditional culture-based methods, however, have several limitations that hamper a prompt diagnosis in bloodstream infection, including long turnaround times and limited sensitivity. In recent years, advances have been made in the development of several technologies that allow the identification of pathogens and their resistance markers directly from whole blood, possibly representing promising alternatives to conventional culture-based methods., Objectives: To review the currently commercially available emerging assays for the diagnosis of bloodstream infections directly from whole blood, including their performance and the available data about their impact on patient outcome., Sources: Peer-reviewed publications relevant to the topic have been searched through PubMed; manufacturers' websites have also been consulted as a data source., Content: We have reviewed available data about the following technologies: multiplex real-time PCR working directly from whole blood (Magicplex Sepsis Real-Time test, Seegene), PCR combined with T2 Magnetic Resonance (T2Candida and T2Bacteria panel, T2Biosystem), and metagenomics-based assays (including SepsiTest, Molzym; iDTECT Dx Blood, PathoQuest; Karius NGS plasma Test, Karius). Performance characteristics, advantages and pitfalls of each method are described, and available data about their impact on patients' clinical outcomes are discussed., Implications: The potential of rapid diagnostic tests applied on whole blood for improving the management of patients with bloodstream infection and sepsis is high, both in terms of reducing turnaround times and improving the sensitivity of pathogen and antimicrobial resistance detection. However, overall, there is still a scarcity of data about the real-life performance of such tests, and well-designed studies are awaited for assessing the impact of these emerging technologies on patient outcomes., (Copyright © 2021. Published by Elsevier Ltd.)

Objectives: Understand the long-term mortality, risk of readmission for sepsis and cause of death following a gram-negative bloodstream infection (GN-BSI)., Methods: This was a propensity-matched study using data linkage of Queensland hospital data, Australia. GN-BSIs were collected from 2005 to 2010 and matched 1:1 to hospital admissions without BSI for age, gender, year of culture collection, frequency of admissions in the prior year and Charlson-Deyo Comorbidity score and each comorbidity within the Charlson-Deyo score. Readmissions for sepsis, mortality and causes of death were evaluated., Results: Cases of GN-BSI were propensity-matched 1:1 to culture-negative hospital admissions (n = 14016). Readmissions for sepsis were higher in the GN-BSI cohort from 91 to 365 days (P < 0.001) and in the four subsequent years (P < 0.001). The five-year survival in the GN-BSI cohort was 52% versus 65% in the culture-negative cases (P < 0.001). Infection was only a common underlying cause of death within the first 90 days. Sepsis was the most common contributing cause of death (CCOD) for the two years following index culture in the GN-BSI cohort., Conclusions: Compared to a similarly vulnerable group of hospital attendees, GN-BSI had higher mortality and demonstrated a persistent long-term risk of readmission for sepsis and sepsis as a CCOD., Competing Interests: Conflict of interest The authors declare no conflict of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: Optimal treatment of carbapenem-resistant Gram-negative bacteria (CR-GNB) infections is uncertain because of the lack of good-quality evidence and the limited effectiveness of available antibiotics. The aim of this survey was to investigate clinicians' prescribing strategies for treating CR-GNB infections worldwide., Methods: A 36-item questionnaire was developed addressing the following aspects of antibiotic prescribing: respondent's background, diagnostic and therapeutic availability, preferred antibiotic strategies and rationale for selecting combination therapy. Prescribers were recruited following the snowball sampling approach, and a post-stratification correction with inverse proportional weights was used to adjust the sample's representativeness., Results: A total of 1012 respondents from 95 countries participated in the survey. Overall, 298 (30%) of the respondents had local guidelines for treating CR-GNB at their facility and 702 (71%) had access to Infectious Diseases consultation, with significant discrepancies according to country economic status: 85% (390/502) in high-income countries versus 59% (194/283) in upper-medium-income countries and 30% (118/196) in lower-middle-income countries/lower-income-countries). Targeted regimens varied widely, ranging from 40 regimens for CR-Acinetobacter spp. to more than 100 regimens for CR-Enterobacteriaceae. Although the majority of respondents acknowledged the lack of evidence behind this choice, dual combination was the preferred treatment scheme and carbapenem-polymyxin was the most prescribed regimen, irrespective of pathogen and infection source. Respondents noticeably disagreed around the meaning of 'combination therapy' with 20% (150/783) indicating the simple addition of multiple compounds, 42% (321/783) requiring the presence of in vitro activity and 38% (290/783) requiring in vitro synergism., Conclusions: Management of CR-GNB infections is far from being standardized. Strategic public health focused randomized controlled trials are urgently required to inform evidence-based treatment guidelines., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Antimicrobial susceptibility testing (AST) is the standard of care for treating bacterial infections. In randomized clinical trials of new antimicrobials, AST might not be performed or reported in real time., Objectives: To determine local, real-time laboratory AST performance, its usage in the trial flow, quality control (QC) of the local testing, central AST performance and the effect of using AST categorization on the trials' primary outcomes., Data Sources: We systematically searched PubMed, Embase, PsychINFO and Web of Science., Eligibility Criteria: We included registered randomized controlled trials published in journals between January 2015 and December 2019., Participants and Interventions: We included trials comparing different antibiotics for the treatment of infections caused predominantly by Gram-negative bacteria., Methods: Primary outcomes for different trial populations were extracted and differences between trial arms were compared for patients with infections caused by susceptible versus non-susceptible bacteria. Results are described narratively., Results: Of 32 randomized trials, 25 trials reported that local AST was performed, 1312 reported the local laboratory AST methods, no trial reported QC, but post-hoc referral for AST at a reference laboratory was common. Patients' outcomes were superior when patients with infections due to susceptible and non-susceptible pathogens were compared post hoc (median difference 14%, interquartile range 8%-24%) in trials allowing this comparison (seven antimicrobials), except for colistin, where 14-day mortality was 9% higher when patients were treated with colistin for colistin-susceptible versus colistin-resistant carbapenem-resistant Acinetobacter baumannii. When excluding patients with pathogens that were non-susceptible to either antimicrobial in the trials, the difference in the primary outcome between the trial arms was reduced in five out of six trials., Conclusions: Trials should perform AST to guide patient inclusion or exclusion from the study and consider the impact of the central laboratory susceptibility results on the study outcomes when using post-hoc reference testing., (Copyright © 2021 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objectives: To evaluate the outbreak size and hospital cost effects of bacterial whole-genome sequencing availability in managing a large-scale hospital outbreak., Methods: We built a hybrid discrete event/agent-based simulation model to replicate a serious bacterial outbreak of resistant Escherichia coli in a large metropolitan public hospital during 2017. We tested the 3 strategies of using whole-genome sequencing early, late (actual outbreak), or not using it and assessed their associated outbreak size and hospital cost. The model included ward dynamics, pathogen transmission, and associated hospital costs during a 5-month outbreak. Model parameters were determined using data from the Queensland Hospital Admitted Patient Data Collection (N = 4809 patient admissions) and local clinical knowledge. Sensitivity analyses were performed to address model and parameter uncertainty., Results: An estimated 197 patients were colonized during the outbreak, with 75 patients detected. The total outbreak cost was A$460 137 (US$317 117), with 6.1% spent on sequencing. Without sequencing, the outbreak was estimated to result in 352 colonized patients, costing A$766 921 (US$528 547). With earlier detection from use of routine sequencing, the estimated outbreak size was 3 patients and cost A$65 374 (US$45 054)., Conclusions: Using whole-genome sequencing in hospital outbreak management was associated with smaller outbreaks and cost savings, with sequencing costs as a small fraction of total hospital costs, supporting the further investigation of the use of routine whole-genome sequencing in hospitals., (Copyright © 2020 ISPOR–The Professional Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)

Objectives: To evaluate the sequential organ failure assessment (SOFA) and modified SOFA (mSOFA) scoring and a novel performance score based on the Karnofsky score for measuring outcome following a bloodstream infection (BSI)., Method: This prospective observational cohort study assessed patients with BSI for mortality and functional outcomes with a novel performance score: the functional bloodstream infection score (FBIS). We also tested the SOFA and, given the difficulties with measuring SOFA on ward-based patients, the mSOFA over the first 7 days following a BSI for their association with outcomes., Results: One hundred participants were prospectively recruited. Mortality at 52 weeks following BSI was 21% (21/100). Only 57% of survivors (39/69) were at their baseline functional status at 52 weeks. Stable or improved SOFA/mSOFA over the first 7 days was associated with survival and return to premorbid performance score (risk ratio 3.2, 95%CI 1.3-9.4, p < 0.01)., Conclusions: The acute change in SOFA/mSOFA was associated with 52-week survival and return to premorbid functional performance. The FBIS measurement represents a simple and easy-to-apply measure of functional performance for patients with BSI and was associated with a high response rate (89%) from participants., (Copyright © 2019 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Background: Most intensive care unit (ICU) patients receive broad-spectrum antibiotics. While lifesaving in some, in others these treatments may be unnecessary and place patients at risk of antibiotic-associated harms., Objectives: To review the literature exploring how we diagnose infection in patients in the ICU and address the safety and utility of a 'watchful waiting' approach to antibiotic initiation with selected patients in the ICU., Sources: A semi-structured search of PubMed and Cochrane Library databases for articles published in English during the past 15 years was conducted., Content: Distinguishing infection from non-infectious mimics in ICU patients is uniquely challenging. At present, we do not have access to a rapid point-of-care test that reliably differentiates between individuals who need antibiotics and those who do not. A small number of studies have attempted to compare early aggressive versus conservative antimicrobial strategies in the ICU. However, this body of literature is small and not robust enough to guide practice., Implications: This issue will not likely be resolved until there are diagnostic tests that rapidly and reliably identify the presence or absence of infection in the ICU population. In the meantime, prospective trials that identify clinical situations wherein it is safe to delay or withhold antibiotic initiation in the ICU until the presence of an infection is proven are warranted., (Copyright © 2019 European Society of Clinical Microbiology and Infectious Diseases. All rights reserved.)

Objectives: To define standardized endpoints to aid the design of trials that compare antibiotic therapies for bloodstream infections (BSI)., Methods: Prospective studies, randomized trials or registered protocols comparing antibiotic therapies for BSI, published from 2005 to 2016, were reviewed. Consensus endpoints for BSI studies were defined using a modified Delphi process., Results: Different primary and secondary endpoints were defined for pilot (small-scale studies designed to evaluate protocol design, feasibility and implementation) and definitive trials (larger-scale studies designed to test hypotheses and influence clinical practice), as well as for Staphylococcus aureus and Gram-negative BSI. For pilot studies of S. aureus BSI, a primary outcome of success at day 7 was defined by: survival, resolution of fever, stable/improved Sequential Organ Failure Assessment (SOFA) score and clearance of blood cultures, with no microbiologically confirmed failure up to 90 days. For definitive S. aureus BSI studies, a primary outcome of success at 90 days was defined by survival and no microbiologically confirmed failure. For pilot studies of Gram-negative BSI, a primary outcome of success at day 7 was defined by: survival, resolution of fever and symptoms related to BSI source, stable or improved SOFA score and negative blood cultures. For definitive Gram-negative BSI studies, a primary outcome of survival at 90 days supported by a secondary outcome of success at day 7 (as previously defined) was agreed., Conclusions: These endpoints provide a framework to aid future trial design. Further work will be required to validate these endpoints with respect to patient-centred clinical outcomes., (Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. All rights reserved.)

Scrub typhus is caused by the obligate intracellular bacterium Orientia tsutsugamushi and is endemic to many countries in the Asia-Pacific region, including tropical Australia. We describe a recent large outbreak amongst military personnel in north Queensland. A total of 45 clinical cases were identified (36% of all potentially exposed individuals). This occurred despite existing military protocols stipulating the provision of doxycycline prophylaxis. Doxycycline resistance in O. tsutsugamushi has been described in South-East Asia, but not Australia. In one case, O. tsutsugamushi was cultured from eschar tissue and blood. Using quantitative real-time PCR to determine susceptibility to doxycycline for the outbreak strain, a minimum inhibitory concentration (MIC) of ≤0.04 μg/mL was found, indicating susceptibility to this agent. It seems most probable that failure to adhere to adequate prophylaxis over the duration of the military exercise accounted for the large number of cases encountered rather than doxycycline resistance., (Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)