Frequency, risk factors, and outcomes of vancomycin-resistant Enterococcus colonization and infection in patients with newly diagnosed acute leukemia: different patterns in patients with acute myelogenous and acute lymphoblastic leukemia

Antimicrobial resistance in patients with haematological malignancies: a scoping review

Antimicrobial resistance (AMR) is a substantial global health threat. Patients with haematological malignancies have an increased risk of AMR infection due to disease-related and treatment-related immunosuppression. This scoping review searched four bibliographic databases from Jan 1, 2000, to Dec 7, 2023, for publications on AMR bacterial infections in patients with haematological malignancies and identified 274 eligible articles. AMR prevalence data extraction focused on WHO bacterial priority pathogens. The prevalence of AMR bacterial infections from seven WHO priority pathogens in patients with haematological malignancies was 35% (95% CI 30-40; I2 99·4%). The most frequent AMR infections reported were bloodstream infections, with the highest reported AMR pathogens in third-generation cephalosporin-resistant Enterobacterales (pooled prevalence rate 44% [95% CI 23-64; I2 99·8%]), meticillin-resistant Staphylococcus aureus (43% [31-54; I2 95·9%]), and vancomycin-resistant enterococci (41% [26-56; I2 96·2%]). 53 (65%) of the 81 studies that reported mortality showed higher mortality rates associated with AMR infections. 168 (61%) studies were conducted in high-income countries, with no studies published from the WHO Africa region, revealing a substantial data gap from low-income and middle-income regions. Future efforts should prioritise standardised reporting measures, robust surveillance, antimicrobial stewardship, and well designed clinical trials, particularly in under-represented regions, to mitigate the effect of AMR on cancer care.

Vancomycin resistant enterococcus risk factors for hospital colonization in hematological patients: a matched case-control study

BACKGROUND

Vancomycin-resistant enterococcus (VRE) was the fastest growing pathogen in Europe in 2022 (+ 21%) but its clinical relevance is still unclear. We aim to identify risk factors for acquired VRE rectal colonization in hematological patients and evaluate the clinical impact of VRE colonization on subsequent infection, and 30- and 90-day overall mortality rates, compared to a matched control group.

METHODS

A retrospective, single center, case-control matched study (ratio 1:1) was conducted in a hematological department from January 2017 to December 2020. Case patients with nosocomial isolation of VRE from rectal swab screening (≥ 48 h) were matched to controls by age, sex, ethnicity, and hematologic disease. Univariate and multivariate logistic regression compared risk factors for colonization.

RESULTS

A total of 83 cases were matched with 83 controls. Risk factors for VRE colonization were febrile neutropenia, bone marrow transplant, central venous catheter, bedsores, reduced mobility, altered bowel habits, cachexia, previous hospitalization and antibiotic treatments before and during hospitalization. VRE bacteraemia and Clostridioides difficile infection (CDI) occurred more frequently among cases without any impact on 30 and 90-days overall mortality. Vancomycin administration and altered bowel habits were the only independent risk factors for VRE colonization at multivariate analysis (OR: 3.53 and 3.1; respectively).

CONCLUSIONS

Antimicrobial stewardship strategies to reduce inappropriate Gram-positive coverage in hematological patients is urgently required, as independent risk factors for VRE nosocomial colonization identified in this study include any use of vancomycin and altered bowel habits. VRE colonization and infection did not influence 30- and 90-day mortality. There was a strong correlation between CDI and VRE, which deserves further investigation to target new therapeutic approaches.

Epidemiology and outcomes of vancomycin-resistant enterococcus infections: a systematic review and meta-analysis

Vancomycin-resistant enterococci (VRE) cause many infections in the healthcare context. Knowledge regarding the epidemiology and burden of VRE infections, however, remains fragmented. We aimed to summarize recent studies on VRE epidemiology and outcomes in hospitals, long-term-care facilities (LTCFs) and nursing homes worldwide based on current epidemiological reports. We searched MEDLINE/PubMed, the Cochrane Library, and Web of Science for observational studies, which reported on VRE faecium and faecalis infections in in-patients published between January 2014 and December 2020. Outcomes were incidence, infection rate, mortality, length of stay (LOS), and healthcare costs. We conducted a meta-analysis on mortality (PROSPERO registration number: CRD42020146389). Of 681 identified publications, 57 studies were included in the analysis. Overall quality of evidence was moderate to low. VRE incidence was rarely and heterogeneously reported. VRE infection rate differed highly (1-55%). The meta-analysis showed a higher mortality for VRE faecium bloodstream infections (BSIs) compared with VSE faecium BSIs (risk ratio, RR 1.46; 95% confidence interval (CI) 1.17-1.82). No difference was observed when comparing VRE faecium vs VRE faecalis BSI (RR 1.00, 95% CI 0.52-1.93). LOS was higher in BSIs caused by E. faecium vs E. faecalis. Only three studies reported healthcare costs. In contrast to previous findings, our meta-analysis of included studies indicates that vancomycin resistance independent of VRE species may be associated with a higher mortality. We identified a lack of standardization in reporting outcomes, information regarding healthcare costs, and state-of-the-art microbiological species identification methodology, which may inform the set-up and reporting of future studies.

Risk of multi-drug-resistant organism acquisition from prior bed occupants in the intensive care unit: a meta-analysis

Multi-drug-resistant organisms (MDROs) have become a global threat to human health. Prior bed occupancy with MDRO infection/colonization is an exposure factor that is closely associated with the MDRO acquisition rates in subsequent bed patients in intensive care units (ICUs). A meta-analysis was conducted to investigate the risk of MDRO acquisition from prior bed occupants in the ICU. PubMed, Cochrane Library, Web of Science, and Embase databases and reference lists were searched for articles published up to December 2021. The Newcastle-Ottawa scale was used for quality assessment. The risk measure was calculated as the odds ratio (OR) and corresponding 95% confidence interval (CI), and the heterogeneity was tested using I2 method and Q test. Eight articles were analysed using a random-effects model. Of the 8147 patients exposed to prior bed occupants infected or colonized with MDROs, 421 had acquired MDROs. The control group consisted of 55,933 patients without exposure factors, of which 1768 had been infected/colonized with MDROs. The pooled acquisition OR for MDROs was 1.80 (95% CI: 1.42, 2.29), P<0.00001. Subgroup analysis based on multi-drug-resistant Gram-positive and Gram-negative organisms was conducted using a fixed-effects model. The results significantly varied between the groups. Heterogeneity was partially explained by the MDRO type. In conclusion, exposure of bed occupants to infected/colonized MDROs significantly increased the risk of MDRO acquisition in subsequent bed occupants.

Clinical outcomes of antimicrobial resistance in cancer patients: a systematic review of multivariable models

BACKGROUND

Infections are major causes of disease in cancer patients and pose a major obstacle to the success of cancer care. The global rise of antimicrobial resistance threatens to make these obstacles even greater and hinder continuing progress in cancer care. To prevent and handle such infections, better models of clinical outcomes building on current knowledge are needed. This internally funded systematic review (PROSPERO registration: CRD42021282769) aimed to review multivariable models of resistant infections/colonisations and corresponding mortality, what risk factors have been investigated, and with what methodological approaches.

METHODS

We employed two broad searches of antimicrobial resistance in cancer patients, using terms associated with antimicrobial resistance, in MEDLINE and Embase through Ovid, in addition to Cinahl through EBSCOhost and Web of Science Core Collection. Primary, observational studies in English from January 2015 to November 2021 on human cancer patients that explicitly modelled infection/colonisation or mortality associated with antimicrobial resistance in a multivariable model were included. We extracted data on the study populations and their malignancies, risk factors, microbial aetiology, and methods for variable selection, and assessed the risk of bias using the NHLBI Study Quality Assessment Tools.

RESULTS

Two searches yielded a total of 27,151 unique records, of which 144 studies were included after screening and reading. Of the outcomes studied, mortality was the most common (68/144, 47%). Forty-five per cent (65/144) of the studies focused on haemato-oncological patients, and 27% (39/144) studied several bacteria or fungi. Studies included a median of 200 patients and 46 events. One-hundred-and-three (72%) studies used a p-value-based variable selection. Studies included a median of seven variables in the final (and largest) model, which yielded a median of 7 events per variable. An in-depth example of vancomycin-resistant enterococci was reported.

CONCLUSIONS

We found the current research to be heterogeneous in the approaches to studying this topic. Methodological choices resulting in very diverse models made it difficult or even impossible to draw statistical inferences and summarise what risk factors were of clinical relevance. The development and adherence to more standardised protocols that build on existing literature are urgent.

Gut colonization with vancomicyn-resistant enterococci among patients with hematologic malignancies

BACKGROUND

Vancomycin-resistant enterococci (VRE) are well known agents that colonize the gastrointestinal tract of immunocompromised patients, especially those with hematologic malignancies. The aim of the current study was to determine the incidence of and risk factors for colonization with VRE among patients with hematologic malignancies.

MATERIALS

For a nine-month period, all patients admitted to the Hematology ward at University Hospital in Pleven, Bulgaria who had hematologic malignancy and duration of hospitalization of more than 48 h were screened for colonization with VRE. The data collected from patients and their medical records during the entire hospital stay included: demographic characteristics, clinical information and information about all antimicrobials used. A longitudinal study was used to assesses the risk factors and statistical analysis was performed using SPSS version 27.0.

RESULTS

A total of 119 patients were enrolled in the study. Colonization with VRE was established in 18 of them. One patient carried two species, resulting in a total of 19 VRE: 12 Enterococcus gallinarum, 4 Enterococcus casseliflavus, 2 Enterococcus faecium and 1 Enterococcus faecalis. VanA phenotype, with high-level resistance of vancomycin (MIC ≥ 256 μg/ml) and teicoplanin (MIC = 96 μg/ml), was demonstrated by one E. faecium, which carried vanA. The other E. faecium and E. faecalis expressed low-level resistance to vancomycin (MICs: 8 μg/ml and 12 μg/ml), susceptibility to teicoplanin (MICs = 0.5 μg/ml) and vanB was detected. All E. gallinarum and E. casseliflavus showed low-level resistance to vancomycin and susceptibility to teicoplanin. E. gallinarum strains were positive for vanC1 and E. casseliflavus for vanC2. Only two patients were colonized with vanA or vanB enterococci and the rest 16 were positive for vanC. The univariate analysis revealed that patient's age (70-79 years; p = 0.025) and multiple myeloma (p = 0.001) are risk factors for VRE acquisition among the investigated patients. In addition, the multivariate analysis confirmed that patient's age (70-79 years) is an independent risk factor for VRE colonization.

CONCLUSIONS

Our results showed that 15.1% of patients with hematologic malignancies were colonized with VRE. There was a distinct prevalence of vanC enterococci. Among the analyzed risk factors, advanced age and multiple myeloma contributed to VRE acquisition.

Genomic and Functional Characterization of Vancomycin-Resistant Enterococci-Specific Bacteriophages in the Galleria mellonella Wax Moth Larvae Model

Phages are naturally occurring viruses that selectively kill bacterial species without disturbing the individual's normal flora, averting the collateral damage of antimicrobial usage. The safety and the effectiveness of phages have been mainly confirmed in the food industry as well as in animal models. In this study, we report on the successful isolation of phages specific to Vancomycin-resistant Enterococci, including Enterococcus faecium (VREfm) and Enterococcus faecalis from sewage samples, and demonstrate their efficacy and safety for VREfm infection in the greater wax moth Galleria mellonella model. No virulence-associated genes, antibiotic resistance genes or integrases were detected in the phages' genomes, rendering them safe to be used in an in vivo model. Phages may be considered as potential agents for therapy for bacterial infections secondary to multidrug-resistant organisms such as VREfm.

Evaluating Initial Empiric Therapy for Neutropenic Fever in Vancomycin-Resistant Enterococcus-Colonized Patients

Objectives

Vancomycin-resistant enterococcus infections impact mortality in oncology patients. Given the low rate of vancomycin-resistant enterococcus bacteremia, low virulence of vancomycin-resistant enterococcus, and advent of rapid diagnostic systems, vancomycin-resistant enterococcus-directed empiric therapy in vancomycin-resistant enterococcus-colonized patients with neutropenic fever may be unnecessary, promoting increased antimicrobial resistance, drug-related toxicity, and cost.

Methods

Vancomycin-resistant enterococcus-colonized adults admitted for hematopoietic stem cell transplantation or induction therapy for acute leukemia/myeloid sarcoma with neutropenic fever were stratified by vancomycin-resistant enterococcus bacteremia development and empiric vancomycin-resistant enterococcus-directed antimicrobial strategy for first neutropenic fever (Empiric Therapy vs. non-Empiric Therapy). Primary endpoints included vancomycin-resistant enterococcus-related, in-hospital, and 100-day mortality rates. Secondary outcomes included vancomycin-resistant enterococcus bacteremia incidence for first neutropenic fever and the entire hospitalization, length of stay, Clostridioides difficile infection rate, and duration and cost of vancomycin-resistant enterococcus-directed therapy.

Results

During first neutropenic fever, 3 of 70 eligible patients (4%) developed vancomycin-resistant enterococcus bacteremia. Although all 3 (100%) were non-Empiric Therapy, no mortality (0%) occurred. Of 67 patients not developing vancomycin-resistant enterococcus bacteremia, 42 (63%) received Empiric Therapy and 25 (37%) non-Empiric Therapy. Empiric Therapy had significantly greater median duration (3 days vs. 0 days; P<.001) and cost ($1604 vs. $0; P<.001) of vancomycin-resistant enterococcus-directed therapy but demonstrated no significant differences in clinical outcomes.

Conclusion

Available data suggest Empiric Therapy may offer no clinical benefit to this population, regardless of whether vancomycin-resistant enterococcus is identified in blood culture or no pathogen is found. Such an approach may only expose the majority of patients to unnecessary vancomycin-resistant enterococcus-directed therapy and drug-related toxicities while increasing institutional drug and monitoring costs. Even in the few patients developing vancomycin-resistant enterococcus bacteremia, waiting until the organism is identified in culture to start directed therapy likely makes no difference in mortality. This lack of benefit warrants consideration to potentially omit empiric vancomycin-resistant enterococcus-directed therapy in first neutropenic fever in many of these patients.

Antimicrobial Stewardship in a Hematological Malignancy Unit: Carbapenem Reduction and Decreased Vancomycin-Resistant Enterococcus Infection

BACKGROUND

Antibiotic stewardship is challenging in hematological malignancy patients.

METHODS

We performed a quasiexperimental implementation study of 2 antimicrobial stewardship interventions in a hematological malignancy unit: monthly antibiotic cycling for febrile neutropenia that included cefepime (± metronidazole) and piperacillin-tazobactam and a clinical prediction rule to guide anti-vancomycin-resistant Enterococcus faecium (VRE) therapy. We used interrupted time-series analysis to compare antibiotic use and logistic regression in order to adjust observed unit-level changes in resistant infections by background community rates.

RESULTS

A total of 2434 admissions spanning 3 years pre- and 2 years postimplementation were included. Unadjusted carbapenem and daptomycin use decreased significantly. In interrupted time-series analysis, carbapenem use decreased by -230 days of therapy (DOT)/1000 patient-days (95% confidence interval [CI], -290 to -180; P < .001). Both VRE colonization (odds ratio [OR], 0.64; 95% CI, 0.51 to 0.81; P < .001) and infection (OR, 0.41; 95% CI, 0.2 to 0.9; P = .02) decreased after implementation. This shift may have had a greater effect on daptomycin prescribing (-160 DOT/1000 patient-days; 95% CI, -200 to -120; P < .001) than did the VRE clinical prediction score (-30 DOT/1000 patient-days; 95% CI, -50 to 0; P = .08). Also, 46.2% of Pseudomonas aeruginosa isolates were carbapenem-resistant preimplementation compared with 25.0% postimplementation (P = .32). Unit-level changes in methicillin-resistant Staphylococcus aureus and extended-spectrum beta lactamase (ESBL) incidence were explained by background community-level trends, while changes in AmpC ESBL and VRE appeared to be independent. The program was not associated with increased mortality.

CONCLUSIONS

An antibiotic cycling-based strategy for febrile neutropenia effectively reduced carbapenem use, which may have resulted in decreased VRE colonization and infection and perhaps, in turn, decreased daptomycin prescribing.

Correlation between Multidrug-Resistant Bacteria Colonization and Bloodstream Infections in Children with Hematolymphoid Malignancies at a Tertiary Cancer Center in India

Background Bloodstream infections with drug-resistant bacteria are associated with a higher morbidity and mortality. Based on previous studies in our institution demonstrating a rising incidence of multidrug resistant organism (MDR) bacteria in bloodstream infections (BSI) and high prevalence of enteric colonization with MDR, the “de-escalation” strategy for empirical antibiotics was adopted in the management of febrile neutropenia in children with hematolymphoid malignancies and MDR colonization. An audit was carried out to determine whether surveillance rectal swabs correlated with blood cultures in febrile neutropenia.

Methods Patient data from January 2015 to July 2016 was examined. Rectal swabs of children with hematolymphoid malignancies were obtained at presentation. Blood cultures were taken during febrile neutropenia. Data were analyzed using SPSS version 24.0. The significance level was set at p < 0.05.

Results Most patients (62.1%) with confirmed BSI were colonized with either extended-spectrum β-lactamase producing organisms (ESBLO) (31.9%) or MDR (30.2%). Majority 116 (62.7%) developed BSI caused by either MDR or ESBLO. In contrast, only 12 (10.6%) patients colonized by sensitive bacteria, developed BSI caused by either MDR or ESBLO. These differences were statistically significant (p < 0.001). Thus, the baseline rectal swab had a sensitivity and a specificity of 90.6% and 59.4%, respectively, in predicting BSI with either MDR or ESBLO.

Conclusions We conclude that high prevalence of MDR colonization at presentation significantly results in MDR BSI, which further results in a significant increase in intensive care unit admissions and mortality. This would justify the use of a “de-escalation” antibiotic policy. Whether such a strategy has been successful in impacting outcomes, would need further study.

Clostridioides difficile infection in patients with hematological malignancy: A multicenter study in Taiwan

BACKGROUND

Among the individuals with hematological malignancy (HM) complicated with Clostridioides difficile infection (CDI), the variables associated with in-hospital mortality and recurrence of CDI were investigated.

MATERIAL AND METHODS

Including adults with HM and those without malignancy suffering from CDI from January 2015 to December 2016 in three hospitals in Taiwan.

RESULTS

Totally 314 patients including 77 with HM and 237 patients without malignancy were included. HM patients more often had low leukocyte counts (<500 cells/mL: 28.6% vs. 2.1%) than those without malignancy and more patients without malignancy had severe CDI than patients with HM (31.6% vs. 14.3%, P = .003), according to the severity score of IDSA/SHEA. Patients with HM had a higher recurrence rate of CDI (14.3%, 11/77 vs. 7.2%, 17/237; P = .07) and longer hospital stay (47.2 ± 40.8 days vs. 33.3 ± 37.3 days; P = .006) than those without malignancy. In the multivariate analyses for those with HM and CDI, the in-hospital mortality was associated with vancomycin-resistant Enterococcus (VRE) colonization or infection (odds ratio [OR] 7.72; P = .01), and C. difficile ribotype 078 complex infection (OR 9.22; P = .03). Moreover underlying hematological malignancy (OR 2.74; P = .04) and VRE colonization/infection (OR 2.71; P = .02) were independently associated with CDI recurrence.

CONCLUSION

Patients with HM complicated with CDI were often regarded as non-severe infection, but had a similar in-hospital mortality rate as those without malignancy. CDI due to ribotype 078 complex isolates heralded a poor prognosis among HM patients.

Risk factors and outcomes associated with the carriage of tigecycline- and vancomycin-resistant Enterococcus faecium

OBJECTIVES

Vancomycin-resistant E. faecium (VRE) is a common cause of healthcare-associated infections. The emergence of VRE with tigecycline resistance (TVRE) is increasing but its impact on patient outcome is still not well defined. This study aimed to assess risk factors for the acquisition of TVRE and of patient outcomes associated with TVRE carriage/infection.

METHODS

At the University Hospital Frankfurt, we conducted a matched pair TVRE-VRE analysis to identify risk factors for TVRE carriage. Bed-to-bed contacts and potential transmission routes were reconstructed. TVRE were whole-genome sequenced to confirm suspected transmission events and to identify tigecycline resistance mechanisms.

RESULTS

76 TVRE cases were identified between 02/2014-04/2017 and compared to VRE colonized or infected controls. TVRE carriage was associated with exposure to tigecycline, an increased rate of bloodstream infections (BSI) with VRE or Candida spp., and higher mortality. Whole-genome sequencing-based analysis of 24 TVRE provided evidence for transmissions of TVRE, also across different wards.

CONCLUSIONS

Tigecycline exposure is the main risk factor for TVRE carriage. VRE/TVRE- and Candida-BSI are associated with worse clinical outcome. Hospital transmission of TVRE may occur despite strict contact precautions, whereas both antimicrobial stewardship and infection control interventions are of high importance to prevent emergence and spread of TVRE.

Colonization with multi-drug-resistant organisms negatively impacts survival in patients with non-small cell lung cancer

Objectives

Multidrug-resistant organisms (MDRO) are considered an emerging threat worldwide. Data covering the clinical impact of MDRO colonization in patients with solid malignancies, however, is widely missing. We sought to determine the impact of MDRO colonization in patients who have been diagnosed with Non-small cell lung cancer (NSCLC) who are at known high-risk for invasive infections.

Materials and methods

Patients who were screened for MDRO colonization within a 90-day period after NSCLC diagnosis of all stages were included in this single-center retrospective study.

Results

Two hundred and ninety-five patients were included of whom 24 patients (8.1%) were screened positive for MDRO colonization (MDRO^pos) at first diagnosis. Enterobacterales were by far the most frequent MDRO detected with a proportion of 79.2% (19/24). MDRO colonization was present across all disease stages and more present in patients with concomitant diabetes mellitus. Median overall survival was significantly inferior in the MDRO^pos study group with a median OS of 7.8 months (95% CI, 0.0–19.9 months) compared to a median OS of 23.9 months (95% CI, 17.6–30.1 months) in the MDRO^neg group in univariate (p = 0.036) and multivariate analysis (P = 0.02). Exploratory analyses suggest a higher rate of non-cancer-related-mortality in MDRO^pos patients compared to MDRO^neg patients (p = 0.002) with an increased rate of fatal infections in MDRO^pos patients (p = 0.0002).

Conclusions

MDRO colonization is an independent risk factor for inferior OS in patients diagnosed with NSCLC due to a higher rate of fatal infections. Empirical antibiotic treatment approaches should cover formerly detected MDR commensals in cases of (suspected) invasive infections.

Vancomycin-resistant enterococci infection and predisposing factors for infection and mortality in patients with acute leukaemia and febrile neutropenia

BACKGROUND

Vancomycin-resistant enterococcus (VRE) is an infectious agent that can increase morbidity and mortality, especially in patients with neutropenia in haematology departments. We analysed VRE infections and mortality rates among VRE colonized patients with acute leukaemia, defined predisposing risk factors for infection and mortality, and investigated the influence of daptomycin or linezolid treatment on mortality.

PATIENTS-METHODS

We included 200 VRE colonized adult acute leukaemia patients with febrile neutropenia between January 2010 and January 2016. Data were collected from electronic files.

RESULTS

There were 179 patients in the colonized group, and 21 patients in the infected group. Enterococcus faecium (van A) was isolated from all patients. The infection rate was 10.5 %, and the types of infections noted were as follows: bloodstream (n = 14; 66.7 %), skin and soft tissue (n = 3; 14.3 %), urinary (n = 2; 9.5 %), and others (9.5 %). In the multivariate logistic regression analysis, exposure to invasive procedures, coinfection status, and >15 days of VRE positivity were independent risk factors for VRE infections. In hospital mortality rates were 57.1 % in the infected group, and 9.5 % in the colonized group (p < 0.001). Older age, female gender, absolute neutropenia, and coinfection status were statistically significant predictor of survival.

CONCLUSION

Vancomycin-resistant enterococcus infections are associated with high morbidity and mortality in haematology patients with neutropenia. Clinicians should be aware of predisposing risk factors for VRE infection to avoid unfavourable outcomes. We believe that larger studies are necessary regarding the influence of treatment with daptomycin and linezolid.

Management of fever and neutropenia in the adult patient with acute myeloid leukemia

INTRODUCTION

Febrile neutropenia represents one of the most common treatment-associated complications in the management of acute myeloid leukemia (AML) and is considered an oncologic emergency. Rapid and detailed workup as well as the initiation of empiric broad-spectrum antibiotic therapy are critical to avoid sepsis and to reduce mortality. Although a definitive source of infection is frequently not identified, the severely immunosuppressed status of the AML patient undergoing cytotoxic therapy results in a high risk for a wide array of bacterial, fungal, and viral etiologies.

AREAS COVERED

The authors herein review the diagnostic and therapeutic approach to the neutropenic leukemia patient based on the current knowledge. Special consideration is given to the rapidly changing therapeutic landscape in AML, creating new challenges in the management of infectious complications.

EXPERT OPINION

Multidrug-resistant organisms pose a major challenge in the management of neutropenic fever patients with hematologic malignancies - including AML. Future directions to improve outcomes demand innovative treatment approaches as well as advances in biomarker research to facilitate diagnosis and disease monitoring. Recent achievements in AML-targeted therapy led to an increased incidence of differentiation syndrome, a potentially life-threatening side effect that frequently resembles clinical infection and requires prompt recognition and aggressive intervention.

Limiting Vancomycin Exposure in Pediatric Oncology Patients With Febrile Neutropenia May Be Associated With Decreased Vancomycin-Resistant Enterococcus Incidence

BACKGROUND

Limited data exists regarding the effects of empiric antibiotic use in pediatric oncology patients with febrile neutropenia (FN) on the development of antibiotic resistance. We evaluated the impact of a change in our empiric FN guideline limiting vancomycin exposure on the development of vancomycin-resistant Enterococcus in pediatric oncology patients.

METHODS

Retrospective, quasi-experimental, single-center study using interrupted timeseries analysis in oncology patients aged ≤18 years with at least 1 admission for FN between 2009 and 2015. Risk strata incorporated diagnosis, chemotherapy phase, Down syndrome, septic shock, and typhlitis. Microbiologic data and inpatient antibiotic use were obtained by chart review. Segmented Poisson regression was used to compare VRE incidence and antibiotic days of therapy (DOT) before and after the intervention.

RESULTS

We identified 285 patients with 697 FN episodes pre-intervention and 309 patients with 691 FN episodes postintervention. The proportion of high-risk episodes was similar in both periods (49% vs 48%). Empiric vancomycin DOT/1000 FN days decreased from 315 pre-intervention to 164 post-intervention (P < .01) in high-risk episodes and from 199 to 115 in standard risk episodes (P < .01). Incidence of VRE/1000 patient-days decreased significantly from 2.53 pre-intervention to 0.90 post-intervention (incidence rate ratio, 0.14; 95% confidence interval, 0.04-0.47; P = .002).

CONCLUSIONS

A FN guideline limiting empiric vancomycin exposure was associated with a decreased incidence of VRE among pediatric oncology patients. Antimicrobial stewardship interventions are feasible in immunocompromised patients and can impact antibiotic resistance.

Microbiota-based approaches to mitigate infectious complications of intensive chemotherapy in patients with acute leukemia

Despite advances in antimicrobial treatments, infection remains a common complication of intensive chemotherapy in patients with acute leukemia. It has become progressively apparent that the current antimicrobial focus has shortcomings that result from disruption of the commensal microbial communities of the gut. These effects, collectively known as dysbiosis, have been increasingly associated worldwide with growing complications such as Clostridioides difficile infection, systemic infections, and antibiotic resistance. A revision of the current practice is overdue. Several innovative concepts have been proposed and tested in animal models and humans, with the overarching goal of preventing damage to the microbiota and facilitating its recovery. In this review, we discuss these approaches, examine critical knowledge gaps, and explore how they may be filled in future research.

Evaluation of the Association Between Gastric Acid Suppression and Risk of Intestinal Colonization With Multidrug-Resistant Microorganisms: A Systematic Review and Meta-analysis

IMPORTANCE

Acid suppressants inhibit gastric acid secretion and disrupt the intestinal microbiome. Whether acid suppression increases the risk of colonization with multidrug-resistant microorganisms (MDROs) is unclear.

OBJECTIVES

To systematically examine the association of use of acid suppressants with the risk of colonization with MDROs and to perform a meta-analysis of current evidence.

DATA SOURCES

PubMed, Embase, the Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials were searched from database inception through July 8, 2019.

STUDY SELECTION

Study selection was performed independently by 2 authors (R.P.J.W. and C.M.J.E.V.-G.) on the basis of predefined selection criteria; conflicts were resolved by consensus or by an adjudicator (K.v.D.). Human observational studies (case control, cohort, and cross-sectional) and clinical trial designs were selected if they quantified the risk of MDRO colonization in users of acid suppressants in comparison with nonusers.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) recommendations were followed. Data were extracted independently by the same 2 authors, and adjudication was conducted when necessary. Risk of bias was assessed according to a modified Newcastle-Ottawa Scale. Pooled odds ratios (ORs) were estimated using random-effects models; heterogeneity was evaluated using the I2 method.

MAIN OUTCOMES AND MEASURES

The primary outcome measure was intestinal colonization with MDROs of the Enterobacterales order (producing extended-spectrum β-lactamases, carbapenemases, or plasmid-mediated AmpC β-lactamases), vancomycin-resistant enterococci, methicillin-resistant or vancomycin-resistant Staphylococcus aureus, or multidrug-resistant Pseudomonas or Acinetobacter species.

RESULTS

A total of 26 observational studies including 29 382 patients (11 439 [38.9%] acid suppressant users) met the selection criteria. Primary meta-analysis of 12 studies including 22 305 patients that provided adjusted ORs showed that acid suppression increased the odds of intestinal carriage of MDROs of the Enterobacterales order and of vancomycin-resistant enterococci by roughly 75% (OR = 1.74; 95% CI, 1.40-2.16; I2 = 68%). The odds were concordant with the secondary pooled analysis of all 26 studies (OR = 1.70; 95% CI, 1.44-1.99; I2 = 54%). Heterogeneity was partially explained by variations in study setting and the type of acid suppression.

CONCLUSIONS AND RELEVANCE

Acid suppression is associated with increased odds of MDRO colonization. Notwithstanding the limitations of observational studies, the association is plausible and is strengthened by controlling for confounders. In view of the global increase in antimicrobial resistance, stewardship to reduce unnecessary use of acid suppressants may help to prevent MDRO colonization.

Efficacy and toxicity for CD22/CD19 chimeric antigen receptor T-cell therapy in patients with relapsed/refractory aggressive B-cell lymphoma involving the gastrointestinal tract

Gastrointestinal (GI) tract is the most common site of extranodal involvement in non-Hodgkin lymphoma. Life-threatening complications of GI may occur because of tumor or chemotherapy. Chimeric antigen receptor (CAR) T-cell therapy has been successfully used to treat refractory/relapse B-cell lymphoma, however, little is known about the efficacy and safety of CAR-T cell therapy for GI lymphoma. Here, we reported the efficacy and safety of CAR-T cell therapy in 14 patients with relapsed/refractory aggressive B-cell lymphoma involving the GI tract. After a sequential anti-CD22/anti-CD19 CAR-T therapy, 10 patients achieved an objective response, and seven patients achieved a complete response. CAR transgene and B-cell aplasia persisted in the majority of patients irrespective of response status. Six patients with partial response or stable disease developed progressive disease; two patients lost target antigens. Cytokine release syndrome (CRS) and GI adverse events were generally mild and manageable. The most common GI adverse events were diarrhea (4/14), vomiting (3/14) and hemorrhage (2/14). No perforation occurred during follow-up. Infection is a severe complication in GI lymphoma. Two patients were infected with bacteria that are able to colonize at GI; one died of sepsis early after CAR-T cells infusion. In conclusion, our study showed promising efficacy and safety of CAR-T cell therapy in refractory/relapsed B-cell lymphoma involving the GI tract. However, the characteristics of CAR-T-related infection in GI lymphoma should be further clarified to prevent and control infection.

Using VRE screening tests to predict vancomycin resistance in enterococcal bacteremia

BACKGROUND AND OBJECTIVE

Enterococcus causes clinically significant bloodstream infections (BSIs). In centers with a higher prevalence of vancomycin resistant enterococcus (VRE) colonization, a common clinical question is whether empiric treatment directed against VRE should be initiated in the setting of a suspected enterococcal BSI. Unfortunately, VRE treatment options are limited, and relatively expensive, and subject patients to the risk of adverse reactions. We hypothesized that the results of VRE colonization screening could predict vancomycin resistance in enterococcal BSI.

METHODS

We reviewed 370 consecutive cases of enterococcal BSI over a 7-year period at 2 tertiary-care hospitals to determine whether vancomycin-resistant BSIs could be predicted based on known colonization status (ie, patients with swabs performed within 30 days, more remotely, or never tested). We calculated sensitivity and specificity, and we plotted negative predictives values (NPVs) and positive predictive values (PPVs) as a function of prevalence.

RESULTS

A negative screening swab within 30 days of infection yielded NPVs of 90% and 95% in settings where <27.0% and 15.0% of enterococcal BSI are resistant to vancomycin, respectively. In patients with known VRE colonization, the PPV for VRE in enterococcal BSI was >50% at any prevalence exceeding 25%.

CONCLUSIONS

The results of a negative VRE screening test result performed within 30 days can help eliminate unnecessary empiric therapy in patients with suspected enterococcal BSI. Conversely, patients with positive VRE screening swabs require careful consideration of empiric VRE-directed therapy when enterococcal BSI appears likely.

Risk Factors for Long-Term Vancomycin-Resistant Enterococci Persistence-A Prospective Longitudinal Study

Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens that require effective infection control measures, representing a challenge for healthcare systems. This study aimed at identifying risk factors associated with prolonged VRE carriage and determining the rate of clearance that allows the discontinuation of contact precautions. During a 2-year study, screening was performed in patients with a history of VRE or at risk of becoming colonized. After bacterial identification and antibiotic susceptibility testing, glycopeptide resistance was confirmed by PCR. Isolates were compared via whole genome sequence-based typing. Risk factors were recorded, and follow-up screening was performed upon readmission, defining patients as long-term carriers if still colonized ≥10 weeks after first detection. Of 1059 patients positive for VRE, carriage status was assessed upon readmission in 463 patients. VRE was cleared in 56.4% of the cases. Risk factors associated with long-term persistence were hospital stays (frequency, length), hemato-oncological disease, systemic treatment with steroids, and use of antibiotics. No specific genotypic clustering was observed in patients with VRE clearance or persistence. VRE clearance is possibly underestimated. The identification of risk factors favoring long-term carriage may contribute to a targeted implementation of infection control measures upon readmission of patients with history of VRE.

Economic burden of antibiotic resistance in ESKAPE organisms: a systematic review

Background

Antibiotic resistance (ABR) is one of the biggest threats to global health. Infections by ESKAPE (Enterococcus, S. aureus, K. pneumoniae, A. baumannii, P. aeruginosa, and E. coli) organisms are the leading cause of healthcare-acquired infections worldwide. ABR in ESKAPE organisms is usually associated with significant higher morbidity, mortality, as well as economic burden. Directing attention towards the ESKAPE organisms can help us to better combat the wide challenge of ABR, especially multi-drug resistance (MDR).

Objective

This study aims to systematically review and evaluate the evidence of the economic consequences of ABR or MDR ESKAPE organisms compared with susceptible cases or control patients without infection/colonization in order to determine the impact of ABR on economic burden.

Methods

Both English-language databases and Chinese-language databases up to 16 January, 2019 were searched to identify relevant studies assessing the economic burden of ABR. Studies reported hospital costs (charges) or antibiotic cost during the entire hospitalization and during the period before/after culture among patients with ABR or MDR ESKAPE organisms were included. The costs were converted into 2015 United States Dollars. Disagreements were resolved by a third reviewer.

Results

Of 13,693 studies identified, 83 eligible studies were included in our review. The most studied organism was S. aureus, followed by Enterococcus, A. baumannii, E. coli, E. coli or/and K. pneumoniae, P. aeruginosa, and K. pneumoniae. There were 71 studies on total hospital cost or charge, 12 on antibiotic cost, 11 on hospital cost or charge after culture, 4 on ICU cost, 2 on hospital cost or charge before culture, and 2 on total direct and indirect cost. In general, ABR or MDR ESKAPE organisms are significantly associated with higher economic burden than those with susceptible organisms or those without infection or colonization. Nonetheless, there were no differences in a few studies between the two groups on total hospital cost or charge (16 studies), antibiotic cost (one study), hospital cost before culture (one study), hospital cost after culture (one study). Even, one reported that costs associated with MSSA infection were higher than the costs for similar MRSA cases.

Conclusions

ABR in ESKAPE organisms is not always, but usually, associated with significantly higher economic burden. The results without significant differences may lack statistical power to detect a significant association. In addition, study design which controls for severity of illness and same empirical antibiotic therapy in the two groups would be expected to bias the study towards a similar, even negative result. The review also highlights key areas where further research is needed.

Decrease in vancomycin-resistant Enterococcus colonization associated with a reduction in carbapenem use as empiric therapy for febrile neutropenia in patients with acute leukemia

OBJECTIVE

To compare the effects of empiric carbapenems versus cycling cefepime and piperacillin/tazobactam on the rates of vancomycin-resistant Enterococcus (VRE) colonization, bloodstream infections, and outcomes of patients admitted with acute leukemia.

DESIGN

Retrospective clinical study with VRE molecular strain typing and gastrointestinal microbiome comparison.

SETTING

A regional referral center for acute leukemia.

PATIENTS

342 consecutive patients admitted with newly diagnosed acute leukemia.

METHODS

In September 2015, we changed our empiric antibiotic of choice for neutropenic fever from a carbapenem to the cycling regimen. We studied 214 consecutive patients during the carbapenem period and 128 during the cycling period. Surveillance for VRE stool colonization was conducted weekly. Representative stool samples were analyzed for VRE MLST types and changes in the composition and diversity of the fecal microbiota.

RESULTS

The change in empiric antibiotics was associated with a significant decrease in VRE colonization (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.27-0.66), a switch in the dominant VRE MLST types on the unit, and some modifications in the gastrointestinal microbiome. There were no differences in total gram-positive or gram-negative BSIs. During the carbapenem period, we observed higher absolute numbers of Candida spp and fewer ESBL BSIs, but these did not reach statistical significance. Patients during the carbapenem period had longer lengths of stay and durations of severe neutropenia and 10% higher hospital cost.

CONCLUSIONS

Carbapenem-sparing empiric antibiotic regimens may have advantages related to VRE ecology, gastrointestinal dysbiosis, duration of neutropenia, cost and length of stay.

A retrospective cohort study of antibiotic exposure and vancomycin-resistant Enterococcus recolonization

OBJECTIVE

In the National Institutes of Health (NIH) Clinical Center, patients colonized or infected with vancomycin-resistant Enterococcus (VRE) are placed in contact isolation until they are deemed "decolonized," defined as having 3 consecutive perirectal swabs negative for VRE. Some decolonized patients later develop recurrent growth of VRE from surveillance or clinical cultures (ie, "recolonized"), although that finding may represent recrudescence or new acquisition of VRE. We describe the dynamics of VRE colonization and infection and their relationship to receipt of antibiotics.

METHODS

In this retrospective cohort study of patients at the National Institutes of Health Clinical Center, baseline characteristics were collected via chart review. Antibiotic exposure and hospital days were calculated as proportions of VRE decolonized days. Using survival analysis, we assessed the relationship between antibiotic exposure and time to VRE recolonization in a subcohort analysis of 72 decolonized patients.

RESULTS

In total, 350 patients were either colonized or infected with VRE. Among polymerase chain reaction (PCR)-positive, culture (Cx)-negative (PCR+/Cx-) patients, PCR had a 39% positive predictive value for colonization. Colonization with VRE was significantly associated with VRE infection. Among 72 patients who met decolonization criteria, 21 (29%) subsequently became recolonized. VRE recolonization was 4.3 (P = .001) and 2.0 (P = .22) times higher in patients with proportions of antibiotic days and antianaerobic antibiotic days above the median, respectively.

CONCLUSION

Colonization is associated with clinical VRE infection and increased mortality. Despite negative perirectal cultures, re-exposure to antibiotics increases the risk of VRE recolonization.

Colonization with multidrug resistant organisms determines the clinical course of patients with acute myeloid leukemia undergoing intensive induction chemotherapy

Introduction

The global spread of multidrug-resistant organisms (MDRO) complicates treatment and isolation measures in hospitals and has shown to increase mortality. Patients with disease- or therapy-related immunodeficiency are especially at risk for fatal infections caused by MDRO. The impact of MDRO colonization on the clinical course of AML patients undergoing intensive induction chemotherapy—a potentially curative but highly toxic treatment option—has not been systematically studied.

Materials & methods

312 AML patients undergoing intensive induction chemotherapy between 2007 and 2015 were examined for MDRO colonization. Patients with evidence for MDRO before or during the hospital stay of induction chemotherapy were defined as colonized, patients who never had a positive swab for MDRO were defined as noncolonized.

Results

Of 312 AML patients 90 were colonized and 130 were noncolonized. Colonized patients suffered from significantly more days with fever, spent more days on the intensive care unit and had a higher median C-reactive protein value during the hospital stay. These findings did not result in a prolonged length of hospital stay or an increased mortality rate for colonized patients. However, in a subgroup analysis, patients colonized with carbapenem-resistant enterobacteriaceae (CRE) had a significantly reduced 60- and 90-day, as well as 1- and 2-year survival rates when compared to noncolonized patients.

Conclusion

Our analysis highlights the importance of intensive MDRO screening especially in patients with febrile neutropenia since persisting fever can be a sign of MDRO-colonization. CRE-colonized patients require special surveillance, since they seem to be at risk for death.

Bloodstream infections with vancomycin-resistant enterococci are associated with a decreased survival in patients with hematological diseases

Enterococcus species are commensals of the human gastrointestinal tract with the ability to cause invasive infections. For patients with hematological diseases, enterococcal bloodstream infections (BSI) constitute a serious clinical complication which may even be aggravated if the pathogen is vancomycin-resistant. Therefore, we analyzed the course of BSI due to vancomycin-susceptible enterococci (VSE) in comparison to vancomycin-resistant enterococci (VRE) on patient survival. In this retrospective single-center study, BSI were caused by VRE in 47 patients and by VSE in 43 patients. Baseline patient characteristics were similar in both groups. Concerning infection-related characteristics, an increased CRP value and an increased rate of prior colonization with multidrug-resistant organisms were detected in the VRE BSI group. More enterococcal invasive infections were found in the VSE group. The primary endpoint, overall survival (OS) at 30 days after BSI, was significantly lower in patients with VRE BSI compared to patients with VSE BSI (74.5% vs. 90.7%, p = 0.039). In a multivariate regression analysis, VRE BSI and a Charlson comorbidity index higher than 4 were independent factors associated with 30-day mortality. Moreover, we found that VRE with an additional teicoplanin resistance showed a trend towards an even lower OS.

Vancomycin-resistant enterococci (VRE): a reason to isolate?

In recent years, an increase in invasive VRE infections has been reported worldwide, including Germany. The most common gene encoding resistance to glycopeptides is VanA, but predominant VanB clones are emerging. Although neither the incidence rates nor the exact routes of nosocomial transmission of VRE are well established, screening and strict infection control measures, e.g. single room contact isolation, use of personal protective clothing by hospital staff and intensified surface disinfection for colonized individuals, are implemented in many hospitals. At the same time, the impact of VRE infection on mortality remains unclear, with current evidence being weak and contradictory. In this short review, we aim to give an overview on the current basis of evidence on the clinical effectiveness of infection control measures intended to prevent transmission of VRE and to put these findings into a larger perspective that takes further factors, e.g. VRE-associated mortality and impact on patient care, into account.

Hospital acquired vancomycin resistant enterococci in surgical intensive care patients - a prospective longitudinal study

Background

Vancomycin resistant enterococci (VRE) occur with enhanced frequency in hospitalised patients. This study elucidates the prevalence of VRE on admission among surgical intensive care unit (SICU) patients, whether these patients are at special risk for VRE acquisition and which risk factors support this process.

Methods

Patients admitted to SICUs of the University Hospital Münster were examined during August-October 2017. VRE screening was performed within 48 h after admission and directly prior to discharge of patients. In parallel risk factors were recorded to estimate their effect on VRE acquisition during SICU stay.

Results

In total, 374 patients (68% male) with a median age of 66 years were admitted to one of the SICUs during the investigation period. Of all, 336 patients (89.8%) were screened on admission and 268 (71.7%) on discharge. Nine patients were admitted with previously known VRE colonisation. Twelve (3.6%) further patients were VRE positive on admission. During ICU stay, eight (3.0%) additional patients turned out to be VRE colonised. Risk factors found to be significantly associated with VRE acquisition were median length of stay on the ICU (14 vs. 3 days; p = 0.01), long-term dialysis (12.5% vs. 2.0% of patients; p = 0.05), and antibiotic treatment with flucloxacillin (28.6% vs. 7.2% of patients; p = 0.01) or piperacillin/tazobactam (57.1% vs. 26.6% of patients; p = 0.01).

Conclusions

SICU patients are not at special risk for VRE acquisition. Previous stay on a SICU should therefore not be considered as specific risk factor for VRE colonisation.

Challenges in Infectious Diseases for Haematologists

Infections remain a threat for patients with haematological malignancies. In accordance with the European Hematology Association roadmap we provide a concise overview regarding the most relevant current challenges in infectious diseases for haematologists. These include bacterial infections and the need for antibiotic stewardship as well as infections with community-acquired respiratory viruses, infections in patients receiving targeted therapies, re-activations of latent infections and vaccination strategies. The following review intends to summarise the most relevant information for clinicians currently caring for patients with haematological malignancies. Recommendations given are based on the guidelines published by the Infectious Diseases Working Party of the German Society of Haematology and Medical Oncology.

Clinical and Genomic Characterization of Recurrent Enterococcal Bloodstream Infection in Patients With Acute Leukemia

Background

Rates and risk factors for recurrent enterococcal bloodstream infection (R-EBSI) and whether the same genetic lineage causes index EBSI and R-EBSI are unknown in patients with acute leukemia (AL) receiving chemotherapy.

Methods

Ninety-two AL patients with EBSI from 2010 to 2015 were included. Enterococcal bloodstream infection was defined by 31 positive blood cultures for Enterococcus faecium or Enterococcus faecalis and fever, hypotension, or chills. Clearance was defined by 31 negative cultures 324 hours after last positive culture and defervescence. Recurrent enterococcal bloodstream infection was defined by a positive blood culture for Enterococcus 324 hours after clearance. Categorical variables were reported as proportions and compared by the χ² test. Continuous variables were summarized by median and interquartile range (IQR) and compared by the Wilcoxon-Mann-Whitney Test. P values <.05 were considered significant. Whole-genome sequencing was performed on available paired BSI isolates from 7 patients.

Results

Twenty-four patients (26%) had 31 episodes of R-EBSI. Median time to R-EBSI (IQR) was 26 (13–50) days. Patients with R-EBSI had significantly longer durations of fever and metronidazole exposure during their index EBSI. Thirty-nine percent of E. faecium R-EBSI isolates became daptomycin-nonsusceptible Enterococcus (DNSE) following daptomycin therapy for index EBSI. Whole-genome sequencing analysis confirmed high probability of genetic relatedness of index EBSI and R-EBSI isolates for 4/7 patients.

Conclusions

Recurrent enterococcal bloodstream infection and DNSE are common in patients with AL and tend to occur within the first 30 days of index EBSI. Duration of fever and metronidazole exposure may be useful in determining risk for R-EBSI. Whole-genome sequencing analysis demonstrates that the same strain causes both EBSI and R-EBSI in some patients.

Estimating the burden of antimicrobial resistance: a systematic literature review

Background

Accurate estimates of the burden of antimicrobial resistance (AMR) are needed to establish the magnitude of this global threat in terms of both health and cost, and to paramaterise cost-effectiveness evaluations of interventions aiming to tackle the problem. This review aimed to establish the alternative methodologies used in estimating AMR burden in order to appraise the current evidence base.

Methods

MEDLINE, EMBASE, Scopus, EconLit, PubMed and grey literature were searched. English language studies evaluating the impact of AMR (from any microbe) on patient, payer/provider and economic burden published between January 2013 and December 2015 were included. Independent screening of title/abstracts followed by full texts was performed using pre-specified criteria. A study quality score (from zero to one) was derived using Newcastle-Ottawa and Philips checklists. Extracted study data were used to compare study method and resulting burden estimate, according to perspective. Monetary costs were converted into 2013 USD.

Results

Out of 5187 unique retrievals, 214 studies were included. One hundred eighty-seven studies estimated patient health, 75 studies estimated payer/provider and 11 studies estimated economic burden. 64% of included studies were single centre. The majority of studies estimating patient or provider/payer burden used regression techniques. 48% of studies estimating mortality burden found a significant impact from resistance, excess healthcare system costs ranged from non-significance to $1 billion per year, whilst economic burden ranged from $21,832 per case to over $3 trillion in GDP loss. Median quality scores (interquartile range) for patient, payer/provider and economic burden studies were 0.67 (0.56-0.67), 0.56 (0.46-0.67) and 0.53 (0.44-0.60) respectively.

Conclusions

This study highlights what methodological assumptions and biases can occur dependent on chosen outcome and perspective. Currently, there is considerable variability in burden estimates, which can lead in-turn to inaccurate intervention evaluations and poor policy/investment decisions. Future research should utilise the recommendations presented in this review.

Trial registration

This systematic review is registered with PROSPERO (PROSPERO CRD42016037510).

Changes in Central Line-Associated Bloodstream Infection Rates Among Children With Immune Compromised Conditions: An 11-Year Review

This article describes changes in central line-associated bloodstream infection (CLABSI) rates among common causative organisms over an 11-year period on a pediatric inpatient unit prior to and following CLABSI reduction strategies. The setting for this descriptive cohort design study was a 32-bed inpatient unit in a tertiary pediatric hospital serving children with immune compromised conditions, including cancer and recipients of hematopoietic stem cell and solid organ transplants. Between January 2006 and December 2016, 265 CLABSIs involving 189 patients were reported. Data were organized into three time periods: 5-year preintervention baseline (2006-2010), implementation of maintenance care bundles (2011-2012), and addition of formalized supportive care practices to the maintenance care bundles (2013-2016). Organisms were categorized into four groups based on the National Health Safety Network organism list. Time-by-class Poisson regression models evaluated changes in CLABSI rates. Characteristics of patients who developed CLABSIs were unchanged. Infections occurred most frequently among patients with hematologic malignancies and neutropenia. Significant log rate decreases in CLABSI rates were observed with the implementation of maintenance care bundles plus enhanced supportive cares compared to preintervention baseline for the following organisms: (1) common commensal organisms (-1.05, p = .005), (2) mucosal barrier injury (MBI) organisms common to the mouth (-.708, p = .007), and (3) other noncommensal/non-MBI pathogens (-.77, p = .005). Rates were unchanged for MBI organisms common to the lower gastrointestinal tract. Central line maintenance care bundles and formalized supportive care practices resulted in sustained decreased CLABSI rates. Additional interventions are needed to reduce CLABSIs involving MBI-associated organisms common to the lower gastrointestinal tract.

Transmission patterns of Streptococcus mutans demonstrated by a combined rep-PCR and MLST approach

OBJECTIVE

Clinical typing methods of the oral pathogen Streptococcus mutans with molecular analysis can be very specific, but expensive. Repetitive extragenic palindromic PCR (rep-PCR) is a relatively inexpensive pre-screening alternative for isolate selection for additional analyses. This study evaluated the prediction accuracy of using rep-PCR to identify S. mutans multilocus sequence typing (MLST) sequence types (ST) among children and their family members. Potential S. mutans strain sources were evaluated for evidence of transmission.

MATERIAL AND METHODS

Ten dendrograms (rep-PCR), with 20 isolates each of the 10 most common S. mutans genotypes, were generated from different subjects. Using a cut-off of 98% similarity, 7-11 isolates of each genotype were selected for MLST analysis to determine ST match/no-match.

RESULTS

Overall, rep-PCR was 75% effective at determining MLST ST match/no-match and 90% effective when applied to related individuals. Most genotypes were further differentiated by MLST. MLST ST diversity was greatest for one genotype (genotype 12, G12) and evidence of transmission among children and their family members was identified by rep-PCR and MLST. Younger children (6 months to 4 years old) shared ST with their mothers but 50% of older children (5-9 years old) had ST not identified in their mother. Six ST were shared between different families and probable source members were identified.

CONCLUSION

This study confirms that rep-PCR offers an affordable option to predict diverse isolates for downstream applications.

CLINICAL RELEVANCE

Using a combined rep-PCR and MLST approach, it is possible to track probable transmission and strain sources for S. mutans genotypes.

Burden and Management of Multidrug-Resistant Organisms in Palliative Care

Palliative care includes comprehensive strategies to optimize quality of life for patients and families confronting terminal illness. Infections are a common complication in terminal illness, and infections due to multidrug-resistant organisms (MDROs) are particularly challenging to manage in palliative care. Limited data suggest that palliative care patients often harbor MDRO. When MDROs are present, distinguishing colonization from infection is challenging due to cognitive impairment or metastatic disease limiting symptom assessment and the lack of common signs of infection. Multidrug-resistant organisms also add psychological burden through infection prevention measures including patient isolation and contact precautions which conflict with the goals of palliation. Moreover, if antimicrobial therapy is indicated per goals of care discussions, available treatment options are often limited, invasive, expensive, or associated with adverse effects that burden patients and families. These issues raise important ethical considerations for managing and containing MDROs in the palliative care setting.

Clinical impact of colonization with multidrug-resistant organisms on outcome after allogeneic stem cell transplantation in patients with acute myeloid leukemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for patients with acute myeloid leukemia (AML). During transplantation, patients undergo a period of severe neutropenia, which puts them at high risk for infectious complications. However, the impact of patient colonization with multidrug-resistant organisms (MDRO) on overall survival remains unclear.

METHODS

In this retrospective, single-center study, the authors analyzed data from 264 patients with AML who underwent a first allo-HSCT between January 2006 and March 2016 at their institution. Primary endpoints were overall survival and nonrelapse-related mortality.

RESULTS

One hundred forty-two of 264 patients (53.8%) were colonized by at least 1 MDRO, mainly with vancomycin-resistant Enterococcus faecalis/faecium (n = 122). The characteristics of colonized patients did not differ from those of MDRO-negative patients with respect to median age (53.5 vs 53 years), cytogenetic risk according to European LeukemiaNet criteria, remission status before allo-HSCT (first or second complete remission: 55.7% vs 60.7%, respectively; active disease: 44.4% vs 39.3%, respectively), donor type, or hematopoietic cell transplantation-comorbidity index (HCT-CI). Compared with noncolonized patients, MDRO-positive patients had an inferior probability of survival at 5 years (43.3% vs 65.5%; P = .002), primarily because of a higher cumulative incidence of nonrelapse-related mortality (33.9% vs 9.4%; P < .001). Death caused by infections occurred in 15.5% of colonized patients versus 4.9% of noncolonized patients. There was no difference in the cumulative incidence of relapse in MDRO-positive versus MDRO-negative patients (33.8% vs 42.1%, respectively; P = .798).

CONCLUSIONS

The current data emphasize the importance of regular MDRO screenings and prompt further investigations into the impact of colonization with MDRO on the immune system after allo-HSCT. Cancer 2018;124:286-96. © 2017 American Cancer Society.

Predictive utility of swab screening for vancomycin-resistant Enterococcus in selection of empiric antibiotics for Enterococcus sterile-site infections: a retrospective cohort study

BACKGROUND

Swab screening for vancomycin-resistant Enterococcus (VRE) is used to identify VRE carriers and thus prevent transmission of this organism. We tested whether screening results could have unintended benefits in predicting the vancomycin susceptibility of subsequent Enterococcus infections experienced by these patients.

METHODS

We conducted a retrospective cohort study of all patients admitted to a large tertiary care hospital between 2010 and 2015 who underwent swab screening for VRE before experiencing an Enterococcus sterile-site infection. We derived test characteristics using the screening result as the test variable predicting the presence or absence of vancomycin resistance in the sterile-site Enterococcus species.

RESULTS

Culture results for sterile-site samples were positive for Enterococcus for 619 patients during the study period. Of these, 488 (79%) had previously undergone VRE screening. A total of 19 (4%) of the 488 screening results were positive for VRE, and 10 (2%) of the sterile-site Enterococcus isolates were resistant to vancomycin. The overall specificity of VRE swabs was 97% (95% confidence interval [CI] 96%-99%), sensitivity was 70% (95% CI 35%-93%), the positive likelihood ratio was 28 (95% CI 14-56), and the negative likelihood ratio was 0.31 (95% CI 0.12-0.79). The post-test probability of vancomycin resistance in a sterile-site culture, given a positive result with VRE screening swab, was 37% using study data and 83% using published aggregate prevalence data for VRE in the United States.

INTERPRETATION

Prior VRE screening swab results represent a useful tool for predicting vancomycin resistance in sterile-site Enterococcus infections. Patients with a positive result for VRE screening swab and Enterococcus identified by culture of sterile-site samples should receive empiric treatment with linezolid or daptomycin until sensitivity results are available.

Decrease in Vancomycin-Resistant Enterococcus Colonization After Extensive Renovation of a Unit Dedicated to the Treatment of Hematologic Malignancies and Hematopoietic Stem-Cell Transplantation

OBJECTIVE While a direct relation between hospital construction and concomitant infection rates has been clearly established, few data are available regarding the environmental decontamination effects of renovation in which surfaces are replaced and regarding subsequent infection incidence. DESIGN Retrospective clinical study with vancomycin-resistant Enterococcus (VRE) molecular strain typing and environmental cultures. SETTING A regional referral center for acute leukemia and hematopoietic stem-cell transplantation. PATIENTS Overall, 536 consecutive hospital admissions for newly diagnosed acute leukemia or a first autologous or allogeneic stem-cell transplantation were reviewed. INTERVENTION During 2009-2010, our unit underwent complete remodeling including replacement of all surfaces. We assessed the effects of this construction on the incidence of hospital-acquired VRE colonization before, during, and after the renovation. RESULTS We observed a sharp decrease in VRE colonization rates (hazard ratio, <0.23; 95% confidence interval, 0.18-0.44; P<.0001) during the first year after the renovation, with a return to near baseline rates thereafter. The known risk factors for VRE colonization appeared to be stable over the study interval. Environmental cultures outside of patient rooms revealed several contaminated areas that are commonly touched by unit personnel. Multilocus sequence typing of VRE isolates that were cryopreserved over the study interval showed that dominant strains prior to construction disappeared and were replaced by other strains after the renovation. CONCLUSIONS Unit reconstruction interrupted endemic transmission of VRE, which resumed with novel strains upon reopening. Contamination of environmental surfaces and shared equipment may play an important role in endemic transmission of VRE. Infect Control Hosp Epidemiol 2017;38:1055-1061.

Enterococcus spp. and S. aureus colonization in neutropenic febrile children with cancer

INTRODUCTION

Febrile neutropenia is one of the most serious treatment-related complications in cancer patients. Susceptible to rapidly progressing infections, which result in prolonged hospitalization and use of broad-spectrum antibiotics, neutropenic patients are subject to colonization by multiresistant agents, which enhances the risk of infections.

METHODS

In this study we included samples collected with nasal, oropharyngeal and anal swabs from hospitalized children with febrile neutropenia following chemotherapy, between March 2014 and 2015, aiming to elucidate colonization by S. aureus and Enterococcus spp., as well as their resistance profile.

RESULTS

S. aureus was found in 22% of the patients and 14% of the events. Methicillin-resistant S. aureus colonized 13.6% of patients. Including anal swabs in the screening increased the identification of colonized patients by 20%. Enterococcus spp. was found in 27% of patients and 17% of episodes. Enterococcal isolates resistant to vancomycin, accounting for 25% of the total, were not isolated in anal swabs at any time, with the oropharyngeal site being much more important. The rate of infection by Enterococcus spp. was 4.5% of all patients and 16% among the colonized patients.

CONCLUSION

Especially in this population, colonization studies including more sites can yield a higher chance of positive results. Establishing the colonization profile in febrile neutropenic children following chemotherapy may help to institute an empirical antibiotic treatment aimed at antibiotic adequacy and lower induction of resistance, thereby decreasing the risk of an unfavorable clinical outcome.

Weekly screening supports terminating nosocomial transmissions of vancomycin-resistant enterococci on an oncologic ward - a retrospective analysis

Background

To investigate the impact of weekly screening within the bundle of infection control measures to terminate vancomycin-resistant enterococci (VRE) transmissions on an oncologic ward.

Methods

A cluster of 12 VRE colonisation and five infections was detected on an oncologic ward between January and April 2015. Subsequently, the VRE point prevalence was detected and, as part of a the bundle of infection control strategies to terminate the VRE cluster, we isolated affected patients, performed hand hygiene training among staff on ward, increased observations by infection control specialists, intensified surface disinfection, used personal protective equipment and initiated an admission screening in May 2015. After a further nosocomial VRE infection in August 2015, a weekly screening strategy of all oncology patients on the respective ward was established while admission screening was continued. Whole genome sequencing (WGS)-based typing was applied to determine the clonal relationship of isolated strains.

Results

Initially, 12 of 29 patients were VRE colonised; of these 10 were hospital-acquired. During May to August, on average 7 of 40 patients were detected to be VRE colonised per week during the admission screening, showing no significant decline compared to the initial situation. WGS-based typing revealed five different clusters of which three were due to vanB- and two vanA-positive enterococci. After an additional weekly screening was established, the number of colonised patients significantly declined to 1/53 and no further nosocomial cases were detected.

Conclusions

Weekly screening helped to differentiate between nosocomial and community-acquired VRE cases resulting in earlier infection control strategies on epidemic situations for a successful termination of nosocomial VRE transmissions.

Vancomycin-resistant enterococci in acute myeloid leukemia and myelodysplastic syndrome patients undergoing induction chemotherapy with idarubicin and cytarabine

We conducted a retrospective study to determine the risk factors associated with vancomycin-resistant enterococci (VRE) acquisition/infection in newly diagnosed acute myeloid leukemia and myelodysplastic syndrome patients undergoing chemotherapy with the 7 + 3 regimen of cytarabine and idarubicin. Although only 2.5% (6/235) patients were colonized with VRE on admission, 59% (134/229) of patients acquired VRE during their hospitalization. Multivariable analysis identified the use of intravenous vancomycin (p = .024; HR: 1.548) and cephalosporin (p = .009; HR: 1.596) as the risk factors for VRE acquisition. VRE infection developed in 14% (33/229) of patients, with bloodstream infections accounting for 82% (27/33) of cases. VRE infection occurred in 25/126 (20%) of the VRE-colonized patients, but only 8/103 (8%) of those who were not (p = .01). Our study provides the evidence for the role of intravenous cephalosporin and vancomycin in VRE acquisition and highlights the clinical significance of VRE colonization in these patients.

Vancomycin-resistant enterococci colonisation, risk factors and risk for infection among hospitalised paediatric patients: a systematic review and meta-analysis

The objective of this study was to estimate the rate and significance of colonisation with vancomycin-resistant enterococci (VRE) among hospitalised children. The PubMed and EMBASE databases were systematically searched (last accessed on 29 May 2016) to identify studies evaluating VRE colonisation of the gastrointestinal tract of hospitalised children in non-outbreak periods. Of 945 non-duplicate citations, 19 studies enrolling 20 234 children were included. The overall and paediatric intensive care unit (PICU) rate of VRE colonisation were both 5% [95% confidence interval (CI) 3-8% overall and 95% CI 2-9% in the PICU] but was 23% in haematology/oncology units (95% CI 18-29%). Studies that were exclusively performed in haematology/oncology units reported significantly higher rates compared with all other studies in the univariate and multivariate analyses (P = 0.001). Previous vancomycin [risk ratio (RR) = 4.34, 95% CI 2.77-6.82] or ceftazidime (RR = 4.15, 95% CI 2.69-6.40) use was a risk factor for VRE colonisation. Importantly, VRE colonisation increased the risk of subsequent VRE infection (RR = 8.75, 95% CI 3.19-23.97). In conclusion, a high rate of VRE colonisation was found among hospitalised children in institutions that performed targeted screening. Importantly, colonised children were almost 9 times more likely to develop subsequent VRE infection. Judicious use of specific antibiotics along with intensification of infection control measures should be considered in high-prevalence institutions. Also, the high incidence of VRE colonisation among children with haematological/oncological diseases identifies a high-risk population.

Outbreak of vancomycin-resistant enterococcus on a haematology ward: management and control

Vancomycin-resistant enterococci (VRE) infections and outbreaks are still infrequent in Spain. A six-month outbreak, which took place in a haematology ward, its control and management are described in this study. A total of 22 patients were colonised and two bloodstream infections occurred during this period. Even though there were two waves of new colonised patients, a multidisciplinary approach, quick interventions and enhanced infection control policies were required in order to control this outbreak.

Colonization With Vancomycin-Resistant Enterococci and Risk for Bloodstream Infection Among Patients With Malignancy: A Systematic Review and Meta-Analysis

Background

Vancomycin-resistant enterococci (VRE) cause severe infections among patients with malignancy, and these infections are usually preceded by gastrointestinal colonization.

Methods

We searched the PubMed and EMBASE databases (up to May 26, 2016) to identify studies that reported data on VRE gastrointestinal colonization among patients with solid or hematologic malignancy.

Results

Thirty-four studies, reporting data on 8391 patients with malignancy, were included in our analysis. The pooled prevalence of VRE colonization in this population was 20% (95% confidence interval [CI], 14%–26%). Among patients with hematologic malignancy, 24% (95% CI, 16%–34%) were colonized with VRE, whereas no studies reported data solely on patients with solid malignancy. Patients with acute leukemia were at higher risk for VRE colonization (risk ratio [RR] = 1.95; 95% CI, 1.17–3.26). Vancomycin use or hospitalization within 3 months were associated with increased colonization risk (RR = 1.92, 95% CI = 1.06–3.45 and RR = 4.68, 95% CI = 1.66–13.21, respectively). Among the different geographic regions, VRE colonization rate was 21% in North America (95% CI, 13%–31%), 20% in Europe (95% CI, 9%–34%), 23% in Asia (95% CI, 13%–38%), and 4% in Oceania (95% CI, 2%–6%). More importantly, colonized patients were 24.15 (95% CI, 10.27–56.79) times more likely to develop a bloodstream infection due to VRE than noncolonized patients.

Conclusions

A substantial VRE colonization burden exists among patients with malignancy, and colonization greatly increases the risk for subsequent VRE bloodstream infection. Adherence to antimicrobial stewardship is needed, and a re-evaluation of the use of vancomycin as empiric therapy in this patient population may be warranted.

Vancomycin-Resistant Enterococcus Colonization and Bacteremia and Hematopoietic Stem Cell Transplantation Outcomes

The association between pre-hematopoietic stem cell transplantation (HSCT) vancomycin-resistant Enterococcus (VRE) colonization, HSCT-associated VRE bacteremia, and HSCT mortality is disputed. We studied 161 consecutive patients with acute leukemia who underwent HSCT at our hospital between 2006 and 2014, of whom 109 also received leukemia induction/consolidation on our unit. All inpatients had weekly VRE stool surveillance. Pre-HSCT colonization was not associated with increases in HSCT mortality but did identify a subgroup of HSCT recipients with a higher risk for VRE bacteremia and possibly bacteremia from other organisms. The major risk factor for pre-HSCT colonization was the number of hospital inpatient days between initial admission for leukemia and HSCT. One-third of evaluable patients colonized before HSCT were VRE-culture negative on admission for HSCT; these patients had an increased risk for subsequent VRE stool surveillance positivity but not VRE bacteremia. Molecular typing of VRE isolates obtained before and after HSCT showed that VRE strains frequently change. Postengraftment VRE bacteremia was associated with a much higher mortality than pre-engraftment VRE bacteremia. Pre-engraftment bacteremia from any organism was associated with an alternative donor and resulted in an increase in hospital length of stay and cost. Mortality was similar for pre-engraftment VRE bacteremia and pre-engraftment bacteremia due to other organisms, but mortality associated with post-engraftment VRE bacteremia was higher and largely explained by associated severe graft-versus-host disease and relapsed leukemia. These data emphasize the importance of distinguishing between VRE colonization before HSCT and at HSCT, between pre-engraftment and postengraftment VRE bacteremia, and between VRE bacteremia and bacteremia from other organisms.

Incidence and Outcomes Associated With Infections Caused by Vancomycin-Resistant Enterococci in the United States: Systematic Literature Review and Meta-Analysis

BACKGROUND

Information about the health and economic impact of infections caused by vancomycin-resistant enterococci (VRE) can inform investments in infection prevention and development of novel therapeutics.

OBJECTIVE

To systematically review the incidence of VRE infection in the United States and the clinical and economic outcomes.

METHODS

We searched various databases for US studies published from January 1, 2000, through June 8, 2015, that evaluated incidence, mortality, length of stay, discharge to a long-term care facility, readmission, recurrence, or costs attributable to VRE infections. We included multicenter studies that evaluated incidence and single-center and multicenter studies that evaluated outcomes. We kept studies that did not have a denominator or uninfected controls only if they assessed postinfection length of stay, costs, or recurrence. We performed meta-analysis to pool the mortality data.

RESULTS

Five studies provided incidence data and 13 studies evaluated outcomes or costs. The incidence of VRE infections increased in Atlanta and Detroit but did not increase in national samples. Compared with uninfected controls, VRE infection was associated with increased mortality (pooled odds ratio, 2.55), longer length of stay (3-4.6 days longer or 1.4 times longer), increased risk of discharge to a long-term care facility (2.8- to 6.5-fold) or readmission (2.9-fold), and higher costs ($9,949 higher or 1.6-fold more).

CONCLUSIONS

VRE infection is associated with large attributable burdens, including excess mortality, prolonged in-hospital stay, and increased treatment costs. Multicenter studies that use suitable controls and adjust for time at risk or confounders are needed to estimate the burden of VRE infections.

Infect Control Hosp Epidemiol. 2017;38:203–215

Room contamination, patient colonization pressure, and the risk of vancomycin-resistant Enterococcus colonization on a unit dedicated to the treatment of hematologic malignancies and hematopoietic stem cell transplantation

BACKGROUND

Contaminated surfaces and colonization pressure are risk factors for vancomycin-resistant Enterococcus (VRE) colonization in intensive care units (ICUs). Whether these apply to modern units dedicated to the care of hematologic malignancies and hematopoietic stem cell transplant (HSCT) procedures is unknown.

METHODS

We reviewed the records of 780 consecutive admissions for acute leukemia, autologous HSCT, or allogeneic HSCT in which the patient was at risk for hospital-acquired VRE and underwent weekly surveillance. We also obtained staff and room cultures, observed staff behavior, and performed VRE molecular strain typing on selected isolates.

RESULTS

The overall rate of VRE colonization was 11.4 cases/1,000 patient days. Cultures of room surfaces revealed VRE isolates in 10% of terminally cleaned rooms. A prior VRE-colonized room occupant did not increase risk, and paired isolates from 20 patients and prior occupants were indistinguishable on molecular typing in only 1 pair. VRE colonization pressure was significantly associated with acquisition. Cultures of unit personnel and shared equipment were negative except for weighing scales. Observation of unit clinical personnel showed high compliance for hand sanitation and but less so for gowns. Conversely, ancillary staff showed poor compliance.

CONCLUSIONS

Transmission of VRE from room surfaces seems to be an infrequent event. Encouraging adherence to surveillance, disinfection, and contact isolation protocols may decrease VRE colonization rates.

Results of Four-Year Rectal Vancomycin-Resistant Enterococci Surveillance in a Pediatric Hematology-Oncology Ward: From Colonization to Infection

Objective:

To investigate the clinical impact of vancomycin-resistant enterococci (VRE) colonization in patients with hematologic malignancies and associated risk factors.

Materials and Methods:

Patients colonized and infected with VRE were identified from an institutional surveillance database between January 2010 and December 2013. A retrospective case-control study was performed to identify the risk factors associated with development of VRE infection in VRE-colonized patients.

Results:

Fecal VRE colonization was documented in 72 of 229 children (31.4%). Seven VRE-colonized patients developed subsequent systemic VRE infection (9.7%). Types of VRE infections included bacteremia (n=5), urinary tract infection (n=1), and meningitis (n=1). Enterococcus faecium was isolated in all VRE infections. Multivariate analysis revealed severe neutropenia and previous bacteremia with another pathogen as independent risk factors for VRE infection development in colonized patients [odds ratio (OR): 35.4, confidence interval (CI): 1.7-72.3, p=0.02 and OR: 20.6, CI: 1.3-48.6, p=0.03, respectively]. No deaths attributable to VRE occurred.

Conclusion:

VRE colonization has important consequences in pediatric cancer patients.