Long-term mortality and causes of death associated with Staphylococcus aureus bacteremia. A matched cohort study

All-cause and Infection-attributable Mortality Amongst Adults With Bloodstream Infection-a Population-based Study

Background

Bloodstream infections (BSIs) are common, life-threatening infections. However, it remains unclear whether deaths following BSIs are primarily from uncontrolled infection or underlying comorbidities. We aimed to determine the overall mortality, infection-attributable mortality, and causes of death for four leading BSI pathogens.

Methods

This retrospective cohort study was conducted within the Secure Anonymized Information Linkage Databank, containing anonymized population-scale electronic health record data for Wales, UK. We included adults with Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, and Staphylococcus aureus BSI between 2010 and 2022 using linked data from Public Health Wales and the Office for National Statistics. Thirty-day all-cause and sepsis-specific mortality, as a proxy for infection-attributable mortality, were compared using Cox proportional hazards and competing risk regression, respectively.

Results

We identified 35 691 adults with BSI (59.6% E coli). Adjusted analyses revealed that all organisms had a higher 30-day mortality versus E coli with Pseudomonas aeruginosa the highest (hazard ratio, 1.96 [1.76-2.17], P < .001). Cancer was the leading cause of death following BSIs for all organisms, particularly deaths occurring between 30 and 90 days (35.9%). A total of 25.5% of deaths within 30 days involved sepsis. Methicillin-resistant Staphylococcus aureus was associated with the highest sepsis mortality versus E coli (hazard ratio, 2.56 [2.10-3.12], P < .001). Peak C-reactive protein was positively associated with increased sepsis mortality (P < .001).

Conclusions

This population-level study challenges the assumption that most deaths following BSIs are directly attributable to uncontrolled infection, particularly subacutely more than 30 days from BSI. Our findings underscore the need for reevaluating clinical trial design and developing better preventive strategies for BSIs.

Longer-term Mortality and Kidney Outcomes of Participants in the Combination Antibiotics for Methicillin-Resistant Staphylococcus aureus (CAMERA2) Trial: A Post Hoc Analysis

Background

The Combination Antibiotic Therapy for Methicillin-Resistant Staphylococcus aureus (CAMERA2) trial ceased recruitment in July 2018, noting that a higher proportion of patients in the intervention arm (combination therapy) developed acute kidney injury (AKI) compared to the standard therapy (monotherapy) arm. We analyzed the long-term outcomes of participants in CAMERA2 to understand the impact of combination antibiotic therapy and AKI.

Methods

Trial sites obtained additional follow-up data. The primary outcome was all-cause mortality, censored at death or the date of last known follow-up. Secondary outcomes included kidney failure or a reduction in kidney function (a 40% reduction in estimated glomerular filtration rate to <60 mL/minute/1.73 m²). To determine independent predictors of mortality in this cohort, adjusted hazard ratios were calculated using a Cox proportional hazards regression model.

Results

This post hoc analysis included extended follow-up data for 260 patients. Overall, 123 of 260 (47%) of participants died, with a median population survival estimate of 3.4 years (235 deaths per 1000 person-years). Fifty-five patients died within 90 days after CAMERA2 trial randomization; another 68 deaths occurred after day 90. Using univariable Cox proportional hazards regression, mortality was not associated with either the assigned treatment arm in CAMERA2 (hazard ratio [HR], 0.84 [95% confidence interval [CI], .59-1.19]; P = .33) or experiencing an AKI (HR at 1 year, 1.04 [95% CI, .64-1.68]; P = .88).

Conclusions

In this cohort of patients hospitalized with methicillin-resistant S aureus bacteremia, we found no association between either treatment arm of the CAMERA2 trial or AKI (using CAMERA2 trial definition) and longer-term mortality.

Staphylococcus aureus bacteraemia and mortality: a population-based study in Olmsted County, Minnesota, from 2006 to 2020

OBJECTIVES

To provide an evaluation of predictors of 6-month mortality in incident Staphylococcus aureus bacteraemia cases.

METHODS

A retrospective population-based study of 541 adult residents of Olmsted County, MN with monomicrobial S. aureus bacteraemia from 1 January 2006 through 31 December 2020. Multivariable Cox regression was used to investigate risk factors of 6-month mortality.

RESULTS

The median (interquartile range [IQR]) age of 541 patients with S. aureus bacteraemia was 66.8 (54.4-78.5) years and 39.6% were female. The median (IQR) Charlson Comorbidity Index was 6 (3-9). Overall, 144 patients died during the six-month period following their initial episode (30-day and 6-month mortality = 16.5% and 26.7%, respectively). In a multivariable analysis, older age, ICU admission, and unknown source of infection were significant predictors of increased 6-month mortality. In contrast, having an infectious diseases (ID) consultation was associated with reduced mortality in the first 2 weeks of follow-up. Secondary analyses revealed an early benefit of ID consultation during the first 30 days of follow-up and that infective endocarditis was an additional predictor of 6-month mortality.

CONCLUSIONS

To our knowledge, this investigation represents the only US population-based study evaluating predictors of mortality in patients with S. aureus bacteraemia. The finding of a short-term survival benefit associated with early ID consultation may be due to more extensive diagnostic efforts.

Nanoparticles for Biomedical Application and Their Synthesis

Tremendous developments in nanotechnology have revolutionized the impact of nanoparticles (NPs) in the scientific community and, more recently, in society. Nanomaterials are by their definition materials that have at least one dimension in range of 1 to 100 nm. Nanoparticles are found in many types of different technological and scientific applications and innovations, from delicate electronics to state-of-the-art medical treatments. Medicine has recognized the importance of polymer materials coated with NPs and utilizes them widely thanks to their excellent physical, chemical, antibacterial, antimicrobial, and protective properties. Emphasis is given to their biomedical application, as the nanoscale structures are in the range of many biological molecules. Through this, they can achieve many important features such as targeted drug delivery, imaging, photo thermal therapy, and sensors. Moreover, by manipulating in a "nano-scale" range, their characteristic can be modified in order to obtain the desired properties needed in particular biomedical fields, such as electronic, optical, surface plasmon resonance, and physic-chemical features.

Risk of Staphylococcus aureus bacteraemia in patients with rheumatoid arthritis and the effect of orthopaedic implants on the risk: a nationwide observational cohort study

OBJECTIVE

It remains disputed how much the risk of Staphylococcus aureus bacteraemia (SAB) is increased in patients with rheumatoid arthritis (RA), and the extent to which orthopaedic implants explain the risk. We assessed SAB incidence rates (IRs) and incidence rate ratios (IRRs), comparing RA patients with a general population cohort (GPC) and individuals with versus without orthopaedic implants.

METHOD

Danish residents aged ≥ 18 years without prior RA or SAB (=GPC) were followed up for RA and microbiologically verified SAB events (1996-2017). IRRs were calculated by age- and sex-stratified Poisson regression adjusted for age, comorbidities, calendar year, and socioeconomic status.

RESULTS

The GPC comprised 5 398 690 individuals. We identified 33 567 incident RA patients (=RA cohort) (median follow-up 7.3 years, IQR 3.6-12.3). We observed 25 023 SAB events (n = 224 in the RA cohort). IRs per 100 000 person-years were 81.0 (RA cohort) and 29.9 (GPC). IRs increased with age. Adjusted IRRs in 18-59-year-old RA patients were 2.6 (95% confidence interval 1.8-3.7) for women and 1.8 (1.1-3.1) for men, compared with same sex and age group GPC. IRRs declined with age. Compared with the GPC without implants, IRRs for RA patients with implants ranged from 1.9 (1.3-2.8) (women ≥ 70 years) to 5.3 (2.2-12.8) (18-59-year-old men).

CONCLUSION

In this nationwide registry-based cohort study RA was a risk factor for SAB, and orthopaedic implants further increased the risk. Clinicians should be aware of potential SAB in patients with RA and orthopaedic implants.

The Impact of a Pharmacist-Driven Staphylococcus aureus Bacteremia Initiative in a Community Hospital: A Retrospective Cohort Analysis

Purpose: Staphylococcus aureus is a leading cause of bacteremia with a 30-day mortality of 20%. This study evaluated outcomes after implementation of a pharmacist-driven Staphylococcus aureus bacteremia (SAB) initiative in a community hospital. Methods: This retrospective cohort analysis compared patients admitted with SAB between May 2015 and April 2018 (intervention group) to those admitted between May 2012 and April 2015 (historical control group). Pharmacists were notified of and responded to blood cultures positive for Staphylococcus aureus by contacting provider(s) with a bundle of recommendations. Components of the SAB bundle included prompt source control, selection of appropriate intravenous antibiotics, appropriate duration of therapy, repeat blood cultures, echocardiography, and infectious diseases consult. Demographics (age, gender, and race) were collected at baseline. Primary outcome was in-hospital mortality. Compliance with bundle components was also assessed. Results: Eighty-three patients in the control group and 110 patients in the intervention group were included in this study. Demographics were similar at baseline. In-hospital mortality was lower in the intervention group (3.6% vs. 15.7%; p = 0.0033). Bundle compliance was greater in the intervention group (69.1% vs. 39.8%; p < 0.0001). Conclusions: We observed a significant reduction in in-hospital mortality and increased treatment bundle compliance in the intervention cohort with implementation of a pharmacist-driven SAB initiative. Pharmacists’ participation in the care of SAB patients in the form of recommending adherence to treatment bundle components drastically improved clinical outcomes. Widespread adoption and implementation of similar practice models at other institutions may reduce in-hospital mortality for this relatively common and life-threatening infection.

Persistence of Lipoproteins and Cholesterol Alterations after Sepsis: Implication for Atherosclerosis Progression

(1) Background: Sepsis is one of the most common critical care illnesses with increasing survivorship. The quality of life in sepsis survivors is adversely affected by several co-morbidities, including increased incidence of dementia, stroke, cardiac disease and at least temporary deterioration in cognitive dysfunction. One of the potential explanations for their progression is the persistence of lipid profile abnormalities induced during acute sepsis into recovery, resulting in acceleration of atherosclerosis. (2) Methods: This is a targeted review of the abnormalities in the long-term lipid profile abnormalities after sepsis; (3) Results: There is a well-established body of evidence demonstrating acute alteration in lipid profile (HDL-c ↓↓, LDL-C -c ↓↓). In contrast, a limited number of studies demonstrated depression of HDL-c levels with a concomitant increase in LDL-C -c in the wake of sepsis. VLDL-C -c and Lp(a) remained unaltered in few studies as well. Apolipoprotein A1 was altered in survivors suggesting abnormalities in lipoprotein metabolism concomitant to overall lipoprotein abnormalities. However, most of the studies were limited to a four-month follow-up and patient groups were relatively small. Only one study looked at the atherosclerosis progression in sepsis survivors using clinical correlates, demonstrating an acceleration of plaque formation in the aorta, and a large metanalysis suggested an increase in the risk of stroke or acute coronary event between 3% to 9% in sepsis survivors. (4) Conclusions: The limited evidence suggests an emergence and persistence of the proatherogenic lipid profile in sepsis survivors that potentially contributes, along with other factors, to the clinical sequel of atherosclerosis.

Prolonged Transcriptional Consequences in Survivors of Sepsis

Survivors of sepsis often suffer from prolonged post-critical illness syndrome secondary to the immune system’s reprogramming. It is unclear if this process is static and pervasive due to methodological difficulties studying long-term outcomes of sepsis. The purpose of this study is to evaluate transcriptional profiles longitudinally in Drosophila melanogaster in the aftermath of sepsis to provide preliminary data for targets playing a role in post-sepsis immunostasis. Adult Drosophila melanogaster were infected with E. coli, and survivors were euthanized at 7, 14, and 21 days. Control flies were subjected to sham stress. Gene profiling was done with RNA-seq, and potential miRNA factors were computed. Profiling identified 55 unique genes at seven days, 61 unique genes at 14 days, and 78 genes at 21 days in sepsis survivors vs. sham control. Each post-sepsis timepoint had a distinctive transcriptional pattern with a signature related to oxidative stress at seven days, neuronal signal transduction at 14 days, and metabolism at 21 days. Several potential miRNA patterns were computed as potentially affecting several of the genes expressed in sepsis survivors. Our study demonstrated that post-sepsis changes in the transcriptome profile are dynamic and extend well into the Drosophila melanogaster natural life span.

Acute Myocardial Infarction and Community-Acquired Staphylococcus aureus Bloodstream Infection: an observational cohort study

BACKGROUND

The relationship between acute myocardial infarction and infection was recognised in the early 20th century during influenza epidemics. Most recently, a case control and self-control design study have identified an association between Staphylococcus aureus infection and acute myocardial infarction. We assessed the association of Community acquired Staphylococcus aureus bloodstream infection (CA-SABSI) with myocardial infarction in the 365 days following blood culture.

METHODS

This was a cohort study design assessing incidence of myocardial infarction 365 days after blood culture for Staphylococcus aureus. Culture negative patients had blood cultures collected at hospital attendance and were matched to the CA-SABSI by sex, 5 year age strata and year of culture collection. Pathology information was linked to hospital administrative data and index of relative socio-economic advantage and disadvantage (ISRAD).

RESULTS

The study included 5157 CA-SABSI cases matched to 10146 blood culture negative cases. Mortality was significantly higher in the CA-SABSI group at 10.9% (562/5157) compared to culture negative cases, 5·1% (521/10146) at 365 days (p &0·0001). In the seven days following index blood culture, excluding recurrent events, there were 89 (1·7%) and 37 (0·4%) myocardial infarction diagnoses in the CA-SABSI and culture negative cases respectively.Multivariable logistic regression for myocardial infarction demonstrated CA-SABSI remained significantly associated after adjusting for known risk factors (OR 5, 3·3 to 7·5, p &0·0001). Myocardial infarctions occurring in this short term risk period were associated with all-cause mortality in Cox proportional hazard model (OR 1·7, 95% CI 1·2-2·4, p&0<005).

CONCLUSIONS

CA-SABSI is associated with an increased short term risk of myocardial infarction which is associated with subsequent mortality.

Comparative Analysis of Age- and Gender-Associated Microbiome in Lung Adenocarcinoma and Lung Squamous Cell Carcinoma

The intra-tumor microbiota has been increasingly implicated in cancer pathogenesis. In this study, we aimed to examine the microbiome in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) and determine its compositional differences with relation to age and gender. After grouping 497 LUAD and 433 LUSC patients by age and gender and removing potential contaminants, we identified differentially abundant microbes in each patient cohort vs. adjacent normal samples. We then correlated dysregulated microbes with patient survival rates, immune infiltration, immune and cancer pathways, and genomic alterations. We found that most age and gender cohorts in both LUAD and LUSC contained unique, significantly dysregulated microbes. For example, LUAD-associated Escherichia coli str. K-12 substr. W3110 was dysregulated in older female and male patients and correlated with both patient survival and genomic alterations. For LUSC, the most prominent bacterial species that we identified was Pseudomonas putida str. KT2440, which was uniquely associated with young LUSC male patients and immune infiltration. In conclusion, we found differentially abundant microbes implicated with age and gender that are also associated with genomic alterations and immune dysregulations. Further investigation should be conducted to determine the relationship between gender and age-associated microbes and the pathogenesis of lung cancer.

Acetaminophen Use Concomitant with Long-Lasting Flucloxacillin Therapy: A Dangerous Combination

Acetaminophen and flucloxacillin both interfere with the γ-glutamyl cycle. Long-lasting concomitant use of flucloxacillin and acetaminophen can lead to 5-oxoproline accumulation and severe high anion gap metabolic acidosis. Females and patients with sepsis, impaired kidney and/or liver function, malnutrition, advanced age, congenital 5-oxoprolinase deficiency and supratherapeutic acetaminophen and flucloxacillin dosage are associated with increased risk. Therefore, a critical attitude towards the prescription of acetaminophen concomitant with flucloxacillin in these patients is needed.

We present the case of a 79-year-old woman with severe 5-oxoprolinaemia after long-lasting treatment with flucloxacillin and acetaminophen, explaining the toxicological mechanism and risk factors, and we make recommendations for acetaminophen use in patients with long-lasting flucloxacillin treatment.

Increased risk of incident primary cancer after Staphylococcus aureus bacteremia: A matched cohort study

Susceptibility to infectious disease may be a marker of immunodeficiency caused by unrecognized cancer. To test the hypothesis, the risk of incident primary cancer was estimated among survivors of Staphylococcus aureus bacteremia (SAB) and compared to a random population cohort.Nation-wide population-based matched cohort study. Cases of SAB were identified from a national database and incident primary cancers were ascertained by record linkage. Incidence rate (IR) and ratio (IRR) with 95% confidence interval (CI) of 27 cancers was calculated by Poisson regression.During the first year of follow-up, 165 and 943 incident cases of cancer occurred in the case cohort (n = 12,918 (1.3%)) and the population cohort (n = 117,465 (0.8%)) for an IR of 3.78 (3.22-4.40) and 2.28 (2.14-2.43) per 100,000 person-years. The IRR was 1.65 (1.40-1.95). Of 27 cancers, 7 cancers occurred more frequently amongst cases than controls: cervical cancer (IRR 37.83 (4.23-338.47)), multiple myeloma (IRR 6.31 (2.58-15.44)), leukemia (IRR 4.73 (2.21-10.10)), sarcoma (IRR 4.73 (1.18-18.91)), liver cancer (IRR 3.64 (1.30-10.21)), pancreatic cancer (IRR 2.8 (1.27-6.16)), and urinary tract cancer (IRR 2.58 (1.23-5.39)). Compared to the control population, the risk of cancer was higher for those without comorbidity and with younger age. The overall risk of cancer during 2 to 5 years of follow-up was not increased (IRR 0.99 (95% CI: 0.89-1.11). However, the risk of pharyngeal cancer was increased (IRR 1.88 (1.04-3.39)) and the risk of liver cancer remained increased (IRR 3.93 (2.36-6.55)).The risk of primary incident cancer was 65% higher in the SAB cohort compared to the population cohort during the first year of follow-up and included 7 specific cancers. The risk was higher for those without comorbidity and with younger age. Screening for these specific cancers in selected populations may allow for earlier detection.

Linking administrative data sets of inpatient infectious diseases diagnoses in far North Queensland: a cohort profile

PURPOSE

To design a linked hospital database using administrative and clinical information to describe associations that predict infectious diseases outcomes, including long-term mortality.

PARTICIPANTS

A retrospective cohort of Townsville Hospital inpatients discharged with an International Classification of Diseases and Related Health Problems 10th Revision Australian Modification code for an infectious disease between 1 January 2006 and 31 December 2016 was assembled. This used linked anonymised data from: hospital administrative sources, diagnostic pathology, pharmacy dispensing, public health and the National Death Registry. A Created Study ID was used as the central identifier to provide associations between the cohort patients and the subsets of granular data which were processed into a relational database. A web-based interface was constructed to allow data extraction and evaluation to be performed using editable Structured Query Language.

FINDINGS TO DATE

The database has linked information on 41 367 patients with 378 487 admissions and 1 869 239 diagnostic/procedure codes. Scripts used to create the database contents generated over 24 000 000 database rows from the supplied data. Nearly 15% of the cohort was identified as Aboriginal or Torres Strait Islanders. Invasive staphylococcal, pneumococcal and Group A streptococcal infections and influenza were common in this cohort. The most common comorbidities were smoking (43.95%), diabetes (24.73%), chronic renal disease (17.93%), cancer (16.45%) and chronic pulmonary disease (12.42%). Mortality over the 11-year period was 20%.

FUTURE PLANS

This complex relational database reutilising hospital information describes a cohort from a single tropical Australian hospital of inpatients with infectious diseases. In future analyses, we plan to explore analyses of risks, clinical outcomes, healthcare costs and antimicrobial side effects in site and organism specific infections.

Association of Infectious Diseases Consultation With Long-term Postdischarge Outcomes Among Patients With Staphylococcus aureus Bacteremia

IMPORTANCE

Staphylococcus aureus bacteremia (SAB) is common and associated with poor long-term outcomes. Previous studies have demonstrated an association between infectious diseases (ID) consultation and improved short-term (ie, within 90 days) outcomes for patients with SAB, but associations with long-term outcomes are unknown.

OBJECTIVE

To investigate the association of ID consultation with long-term (ie, 5 years) postdischarge outcomes among patients with SAB.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included all patients (N = 31 002) with a first episode of SAB who were discharged alive from 116 acute care units of the nationwide Veterans Health Administration where ID consultation was offered. Data were collected from January 2003 to December 2014, with follow-up through September 30, 2018. Data analysis was conducted from February to December 2019.

EXPOSURES

Infectious diseases consultation during the index hospital stay.

MAIN OUTCOMES AND MEASURES

The primary outcome was time to development of a composite event of all-cause mortality or recurrence of SAB within 5 years of discharge. As secondary outcomes, SAB recurrence and all-cause mortality with and without recurrence were analyzed while accounting for semicompeting risks.

RESULTS

The cohort included 31 002 patients (30 265 [97.6%] men; median [interquartile range] age at SAB onset, 64.0 [57.0-75.0] years). Among 31 002 patients, there were 18 794 (60.6%) deaths, 4772 (15.4%) SAB recurrences, and 20 414 (65.8%) composite events during 5 years of follow-up; 12 773 deaths (68.0%) and 2268 recurrences (47.5%) occurred more than 90 days after discharge. Approximately half of patients (15 360 [49.5%]) received ID consultation during the index hospital stay; ID consultation was associated with prolonged improvement in the composite outcome (adjusted hazard ratio at 5 years, 0.71; 95% CI, 0.68-0.74; P < .001). Infectious diseases consultation was also associated with improved outcomes when all-cause mortality without recurrence and SAB recurrence were analyzed separately (all-cause mortality without recurrence: adjusted hazard ratio at 5 years, 0.77; 95% CI, 0.74-0.81; P < .001; SAB recurrence: adjusted hazard ratio at 5 years, 0.68; 95% CI, 0.64-0.72; P < .001).

CONCLUSIONS AND RELEVANCE

Having an ID consultation during the index hospital stay among patients with SAB was associated with improved postdischarge outcomes for at least 5 years, suggesting that contributions of ID specialists to management during acute infection may have a substantial influence on long-term outcomes. Further investigations of the association of ID consultation with outcomes after S aureus should include long-term follow-up.

Identification of Key Genes and Pathways in Myeloma side population cells by Bioinformatics Analysis

Background: Multiple myeloma (MM) is the second most common hematological malignancy, which is still incurable and relapses inevitably, highlighting further understanding of the possible mechanisms. Side population (SP) cells are a group of enriched progenitor cells showing stem-like phenotypes with a distinct low-staining pattern with Hoechst 33342. Compared to main population (MP) cells, the underlying molecular characteristics of SP cells remain largely unclear. This bioinformatics analysis aimed to identify key genes and pathways in myeloma SP cells to provide novel biomarkers, predict MM prognosis and advance potential therapeutic targets. Methods: The gene expression profile GSE109651 was obtained from Gene Expression Omnibus database, and then differentially expressed genes (DEGs) with P-value <0.05 and |log2 fold-change (FC)| > 2 were selected by the comparison of myeloma light-chain (LC) restricted SP (LC/SP) cells and MP CD138⁺ cells. Subsequently, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis, protein-protein interaction (PPI) network analysis were performed to identify the functional enrichment analysis of the DEGs and screen hub genes. Cox proportional hazards regression was used to select the potential prognostic DEGs in training dataset (GSE2658). The prognostic value of the potential prognostic genes was evaluated by Kaplan-Meier curve and validated in another external dataset (MMRF-CoMMpass cohort from TCGA). Results: Altogether, 403 up-regulated and 393 down-regulated DEGs were identified. GO analysis showed that the up-regulated DEGs were significantly enriched in innate immune response, inflammatory response, plasma membrane and integral component of membrane, while the down-regulated DEGs were mainly involved in protoporphyrinogen IX and heme biosynthetic process, hemoglobin complex and erythrocyte differentiation. KEGG pathway analysis suggested that the DEGs were significantly enriched in osteoclast differentiation, porphyrin and chlorophyll metabolism and cytokine-cytokine receptor interaction. The top 10 hub genes, identified by the plug-in cytoHubba of the Cytoscape software using maximal clique centrality (MCC) algorithm, were ITGAM, MMP9, ITGB2, FPR2, C3AR1, CXCL1, CYBB, LILRB2, HP and FCER1G. Modules and corresponding GO enrichment analysis indicated that myeloma LC/SP cells were significantly associated with immune system, immune response and cell cycle. The predictive value of the prognostic model including TFF3, EPDR1, MACROD1, ARHGEF12, AMMECR1, NFATC2, HES6, PLEK2 and SNCA was identified, and validated in another external dataset (MMRF-CoMMpass cohort from TCGA). Conclusions: In conclusion, this study provides reliable molecular biomarkers for screening, prognosis, as well as novel therapeutic targets for myeloma LC/SP cells.

Age-Dependent Increase in Incidence of Staphylococcus aureus Bacteremia, Denmark, 2008-2015

During 2008–2015, overall incidence increased by 50%, with a dramatic increase in persons >80 years of age.

Staphylococcus aureus bacteremia (SAB) is a major cause of illness and death worldwide. We analyzed temporal trends of SAB incidence and death in Denmark during 2008–2015. SAB incidence increased 48%, from 20.76 to 30.37 per 100,000 person-years, during this period (p<0.001). The largest change in incidence was observed for persons >80 years of age: a 90% increase in the SAB rate (p<0.001). After adjusting for demographic changes, annual rates increased 4.0% (95% CI 3.0–5.0) for persons <80 years of age, 8.4% (95% CI 7.0–11.0) for persons 80–89 years of age, and 13.0% (95% CI 9.0–17.5) for persons >90 years of age. The 30-day case-fatality rate remained stable at 24%; crude population death rates increased by 53% during 2008–2015 (p<0.001). Specific causes and mechanisms for this rapid increase in SAB incidence among the elderly population remain to be clarified.

Formal Infectious Diseases Specialist Consultation Improves Long-term Outcome of Methicillin-Sensitive Staphylococcus aureus Bacteremia

Background

Formal infectious diseases specialist (IDS) consultation has been shown to improve short-term outcomes in Staphylococcus aureus bacteremia (SAB), but its effect on long-term outcomes lacks evaluation.

Methods

This retrospective study followed 367 methicillin-sensitive (MS) SAB patients for 10 years. The impact of formal IDS consultation on risk for new bacteremia and outcome during long-term follow-up was evaluated. Patients who died within 90 days were excluded to avoid interference from early deceased patients.

Results

Three hundred four (83%) patients had formal IDS consultation, whereas 63 (17%) received informal or no IDS consultation. Formal consultation, compared with informal or lack of consultation, was associated with a reduced risk of new bacteremia caused by any pathogen within 1 year (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.18–0.84; P = .014; 8% vs 17%) and within 3 years (OR, 0.39; 95% CI, 0.19–0.80; P = .010; 9% vs 21%), whereas a trend toward lower risk was observed within 10 years (OR, 0.56; 95% CI, 0.29–1.08; P = .079; 16% vs 25%). Formal consultation, compared with informal or lack of consultation, improved outcomes at 1 year (OR, 0.16; 95% CI, 0.06–0.44; P < .001; 3% vs 14%), at 3 years (OR, 0.19; 95% CI, 0.09–0.42; P < .001; 5% vs 22%), and at 10 years (OR, 0.43; 95% CI, 0.24–0.74; P = .002; 27% vs 46%). Considering all prognostic parameters, formal consultation improved outcomes (HR, 0.42; 95% CI, 0.27–0.65; P < .001) and lowered risk for any new bacteremia (OR, 0.45; 95% CI, 0.23–0.88; P = .02) during 10 years of follow-up.

Conclusions

MS-SAB management by formal IDS consultation, compared with informal or lack of IDS consultation, reduces risk for new bacteremia episodes and improves long-term prognosis up to 10 years.

Cervicofacial Infections Caused by Staphylococcus aureus

Staphylococcus aureus (S. aureus) is an opportunistic pathogen that causes a wide range of diseases. Dissemination of perioral infections is a common problem in the field of oral and maxillofacial surgery. The aim of the study was to evaluate S. aureus carriage in the oral cavity and its dissemination to different cervicofacial regions. Clinical case 1 is a patient with a systemic history of type I diabetes which led to foot amputation one year previou sly, who presented alteration of ocular motility and the culture showed Grampositive cocci compatible with S. aureus. The patient was discharged after eight days of antibiotic therapy and drainage. Clinical case 2 was a young female without any comorbidities who had never been hospitalized before or even exposed to the hospital environment. The presence of lesions compatible with necrotizing fasciitis (NF) in the lower lip mucosal region, rapid evolution of the infection to deep planes, and evolution of the clinical picture alerted health-care providers to the need for prompt care. Clinical case 3 was an immunosuppressed patient with cellulitis which is a bacterial infection of the skin and soft tissues that occurs when the physical barrier of the skin and soft tissues, the immune system, and/or the circulatory system are affected. S. aureus is an opportunistic pathogen which causes a wide range of diseases. It inhabits the oral cavity, from where it can spread to distant cervicofacial regions. This is why it is important for health-care professionals to be aware of this niche in case of dissemination in order to provide prompt diagnosis and appropriate treatment.

How automatic notification of infectious disease specialists impacted the management of Staphylococcus aureus bacteremia in a community hospital setting

Objective: The objective of this study was to review the impact of an automatic email notification to infectious disease consultants.

Design: Cases were identified from a community hospital system microbiology database by at least one positive blood culture. Records were reviewed both before (2013 and 2014) and after (2015 and 2016) the implementation of the automated email system (intervention). Prior to this policy, consultation with the infectious disease (ID) specialist was at the discretion of the primary team.

Results: There were no significant differences in 30-day mortality between the two groups (18 vs 20%, p = 0.10). However, a trend of shorter hospital stays (12.2 vs 9.5 days, p = 0.03) and reduced 30 day readmissions (40% vs 19%, p = 0.03) was observed and antibiotics prescribed for complicated cases was more appropriate (57% vs 85%, p = 0.004).

Conclusions: In this study population, the implementation of an automatic email generator to ID specialists was associated with a shorter hospital length of stay, less 30-day readmissions and more appropriate length of antibiotics prescribed in complicated cases of SAB. The authors recommend future studies replicating the methodology employed here with larger sample sizes before consideration of employing a similar automatic email ID consult generation at other health systems.

Predictors of one-year all-cause mortality and infection-related mortality in patients with Staphylococcus aureus bacteraemia

OBJECTIVES

Staphylococcus aureus bacteraemia (SAB) is a common infection associated with significant short-term mortality. Little is known about long-term prognosis. The aim of this study was to determine one-year all-cause mortality and infection-related mortality and associated predictors.

METHODS

Data from 303 consecutive patients with SAB were prospectively collected from March 2011 to February 2014. All patients were followed one year or until death.

RESULTS

One-year all-cause- and infection-related mortality were 36.7% and 20.8%, respectively. For all-cause mortality, in multivariable logistic regression analysis, age 70-79 years (OR 3.9; 95% CI 1.7-9.1; p = .001), Charlson Comorbidity index ≥3 (OR 6.9; 95% CI 2.7-17.3; p < .001), healthcare-associated infection (OR 2.3; 95% CI 1.1-4.9; p = .03) and severe sepsis (OR 3.6; 95% CI 1.8-7.1; p < .001) were independent predictors of outcome. For infection-related mortality, the predictors were similar, except for healthcare-associated infection that lost significance. The vast majority (89%) of infection-related deaths occurred within 30 days.

CONCLUSIONS

This study demonstrates additional significant all-cause mortality in patients with SAB beyond 30 days to one year, mainly driven by high age and comorbidity. As a result, SAB can be considered an indirect marker of high risk of death in these patients. Follow-up beyond 30 days does not add significant information with respect to infection-related mortality.

Long-term morbidity and mortality following bloodstream infection: A systematic literature review

OBJECTIVES

Bloodstream infection results in significant short-term morbidity and mortality. No literature review has studied the long-term outcome following a bloodstream infection. This PROSPERO registered systematic review evaluated studies, which measured the association of a bloodstream infection with long-term morbidity and mortality.

METHODS

Databases were systematically searched for studies of adult patients reporting morbidity and/or mortality one year or more following a bloodstream infection in comparison to a matched cohort without a bloodstream infection.

RESULTS

Ten observational studies were included in the final analysis. Five studies assessed only mortality, two assessed morbidity and mortality and three studies assessed morbidity only. The one year mortality ranged from between 8 and 48% for patients with bloodstream infection. The pooled risk ratio of death at one year was significantly higher for patients with bloodstream infection when compared to the matched cohort (RR 4.04 [95% CI 1.84-8.87]).

CONCLUSIONS

Bloodstream infection was associated with poor long-term outcome measured at one year when compared to matched controls. More evidence is needed to determine if this association is causative.

Morbidity from in-hospital complications is greater than treatment failure in patients with Staphylococcus aureus bacteraemia

BACKGROUND

Various studies have identified numerous factors associated with poor clinical outcomes in patients with Staphylococcus aureus bacteraemia (SAB). A new study was created to provide deeper insight into in-hospital complications and risk factors for treatment failure.

METHODS

Adult patients hospitalised with Staphylococcus aureus bacteraemia (SAB) were recruited prospectively into a multi-centre cohort. The primary outcome was treatment failure at 30 days (composite of all-cause mortality, persistent bacteraemia, or recurrent bacteraemia), and secondary measures included in-hospital complications and mortality at 6- and 12-months. Data were available for 222 patients recruited from February 2011 to December 2012.

RESULTS

Treatment failure at 30-days was recorded in 14.4% of patients (30-day mortality 9.5%). Multivariable analysis predictors of treatment failure included age > 70 years, Pitt bacteraemia score ≥ 2, CRP at onset of SAB > 250 mg/L, and persistent fevers after SAB onset; serum albumin at onset of SAB, receipt of appropriate empiric treatment, recent healthcare attendance, and performing echocardiography were protective. 6-month and 12-month mortality were 19.1% and 24.2% respectively. 45% experienced at least one in-hospital complication, including nephrotoxicity in 19.5%.

CONCLUSIONS

This study demonstrates significant improvements in 30-day outcomes in SAB in Australia. However, we have identified important areas to improve outcomes from SAB, particularly reducing renal dysfunction and in-hospital treatment-related complications.

Staphylococcus aureus bacteraemia and endocarditis - epidemiology and outcome: a review

PURPOSE

To review the epidemiology of Staphylococcus aureus bacteraemia (SAB) and endocarditis (SAE), and discuss the short- and long-term outcome.  Materials and methods: A literature review of the epidemiology of SAB and SAE.

RESULTS

The reported incidence of SAB in Western countries is 16-41/100,000 person-years. Increasing incidence has been observed in many regions, in Iceland by 27% during 1995-2008. The increase is believed to depend on changes in population risk factors and possibly better and more frequent utilization of diagnostic procedures. S. aureus is now the leading causes of infective endocarditis (IE) in many regions of the world. It accounts for 15-40% of all IE cases, and the majority of cases in people who inject drugs (PWID). Recently, the incidence of SAE in PWID in Stockholm, Sweden, was found to be 2.5/1000 person-years, with an in-hospital mortality of 2.5% in PWID as compared to 15% in non-drug users. The 30-day mortality associated with SAB amounts to 15-25% among adults in Western countries, but is lower in children (0-9%). Mortality associated with SAE is high (generally 20-30% in-hospital mortality), and symptomatic cerebral embolizations are common (12-35%). The 1-year mortality reported after SAB and SAE is 19-62% and reflects deaths from underlying diseases and complications caused by the infection. In a subset of SAE cases, valvular heart surgery is needed (15-45%), but active intravenous drug use seems to be a reason to refrain from surgery. Despite its importance, there are insufficient data on the optimal management of SAB and SAE, especially on the required duration of antibiotic therapy.  Conclusions: The epidemiology of SAB and SAE has been changing in the past decades. They still carry a substantial morbidity and mortality. Intensified studies on treatment are warranted for improving patient outcome.

Diabetes increases the risk of disease and death due to Staphylococcus aureus bacteremia. A matched case-control and cohort study

BACKGROUND

This study investigated the effect and influence of diabetes severity on susceptibility and 30-day mortality of Staphylococcus aureus bacteremia (SAB).

METHODS

Nationwide population-based study of individuals with SAB and matched population controls. Diabetes severity was categorized based on International Classification of Diseases codes and the odds ratio (OR) with 95% confidence intervals (CI) of SAB associated with diabetes was estimated by conditional logistic regression analysis. Hazard ratios (HR) were analyzed by Cox proportional regression. Analyses were adjusted for age, sex, comorbidity, hospital contact and diabetes duration.

RESULTS

Of 25,855 SAB cases, 2797 (10.8%) had diabetes and 2913 (11.3%) had diabetes with complications compared to 14,189 (5.5%) and 5499 (2.1%) of 258,547 controls. This corresponded to an increased risk of SAB associated with diabetes without complications (OR 1.83 (95% CI 1.74-1.92)) and of diabetes with complications (OR 3.62 (95% CI 3.43-3.81) compared to no diabetes. The risk of SAB was highest within the first year of diabetes. Diabetes without complications was associated with an increased risk of 30-day mortality (HR 1.62 (95% CI 1.01-2.60)) compared to no diabetes. Diabetes with complications was overall not associated with increased 30-d mortality (HR 1.36 (95% CI 0.84-2.20)) except for individuals with ketoacidosis/coma (HR 2.01 (95% 1.17-3.45)).

CONCLUSIONS

Diabetes, particularly, diabetes with complications significantly increased the risk of SAB. In contrast, there was an increased risk of 30-day mortality after SAB for diabetes without complications but not for diabetes with complications overall. Diabetes with ketoacidosis/coma conferred the highest relative risk of 30-day mortality.