The prevention and management of infections due to multidrug resistant organisms in haematology patients

Preneutropenic Fever in Patients With Hematological Malignancies: A Novel Target for Antimicrobial Stewardship

Background

Many patients with hematological malignancy develop fever after chemotherapy/conditioning but before chemotherapy-induced neutropenia (preneutropenic fever [PNF]). The proportion of PNF with an infectious etiology is not well established.

Methods

We conducted a single-center, prospective observational substudy of PNF (neutrophils >0.5 cells/μL, ≥38.0°C) in adults receiving acute myeloid leukemia (AML) chemotherapy, or allogeneic hematopoietic cell transplant (allo-HCT) conditioning enrolled in a neutropenic fever randomized controlled trial between 1 January and 31 October 2018. Eligible patients had anticipated neutropenia ≥10 days and exclusions included concurrent infection and/or neutropenia prior to chemotherapy or conditioning. PNF rates and infections encountered were described. Associations between noninfectious etiologies and fever were explored. Antimicrobial therapy prescription across preneutropenic and neutropenic periods was examined.

Results

Of 62 consecutive patients included (43 allo-HCT, 19 AML), 27 had PNF (44%) and 5 (19%) had an infective cause. Among allo-HCT, PNF occurred in 14 of 17 (82%) who received thymoglobulin; only 1 of 14 (7%) had infection. During AML chemotherapy, 18 of 19 received cytarabine, of which 8 of 18 (44%) had PNF and 3 of 8 (38%) had infection. Most patients with PNF had antimicrobial therapy continued into the neutropenic period (19/27 [70%]). Those with PNF were more likely to be escalated to broader antimicrobial therapy at onset/during neutropenic fever (5/24 [21%] vs 2/30 [7%]).

Conclusions

Rates of PNF were high, and documented infection low, leading to prolonged and escalating antimicrobial therapy. In the absence of infection, early cessation of empiric therapy after PNF is recommended as an important stewardship intervention.

Replicon-Based Typing About IncG Plasmids and Molecular Characterization of Five IncG Plasmids Carrying Carbapenem Resistance Gene bla KPC-2

Purpose

To investigate the genetic diversity of IncG plasmids, we have proposed a typing scheme based on replicon repA and performed comparative genomic analysis of five IncG plasmids from China.

Methods

p30860-KPC, p116965-KPC, pA1705-KPC, pA1706-KPC and pNY5520-KPC total in five IncG plasmids from clinical isolates of Pseudomonas and Enterobacteriaceae, respectively, were fully sequenced and were compared with the previously collected reference plasmid p10265-KPC.

Results

Based on phylogeny, IncG-type plasmids are divided into IncG-I to IncG-VIII, the five plasmids belong to IncG-VIII. A detailed sequence comparison was then presented that the IncG plasmid involved accessory region I (Tn5563a/b/c/d/e), accessory region II (ISpa19), and accessory region III (bla KPC-2-region). Expect for the pNY5520-KPC, the rest of the plasmids had the same backbone structure as the reference one. Within the plasmids, insertion sequences Tn5563d and Tn5563e were identified, a novel unknown insertion region was found in Tn5563b/c/d/e. In addition, Tn6376b and Tn6376c were newly designated in the study.

Conclusion

The data presented here including a typing scheme and detailed genetic comparison which provide an insight into the diversification and evolution history of IncG plasmids.

Low Motor Dexterity and Significant Behaviors Following Hospitalized Isolation in Children

The main objective of this study was to describe the cortical patterns of brain activity during a gross dexterity task and develop a behavioral profile of children experiencing isolation. A cross-sectional assessment was conducted during one visit. Sample: Four pediatric patients who had undergone isolation within a hospital comprised the full data collection. During the collection, participants completed the Box and Blocks Test of gross manual dexterity while undergoing imaging of the motor cortex using functional near-infrared spectroscopy. Participants also completed a Behavioral Assessment System for Children, Third Edition (BASC-3) self-report, which was analyzed along with a parent report to quantify their emotional and social behaviors. All participants displayed lower gross dexterity levels than normative data. Furthermore, three out of the four participants displayed ipsilateral dominance of the motor cortex during the dexterity task. Three of the participants displayed behavioral measures reported within clinically significant or at-risk scores. Clinically significant behavioral scores coupled with lower than expected manual dexterity values and ipsilateral hemispheric dominance indicate that neuroplastic changes can occur in populations undergoing hospitalized isolation. While the impacts of the treatments and isolation in this case cannot be separated, further studies should be conducted to understand these impacts of isolation.

Evaluation of a Shotgun Metagenomics Approach for Detection of ESBL- and/or Carbapenemase-Producing Enterobacterales in Culture Negative Patients Recovered from Acute Leukemia

Patients diagnosed with acute leukemia (AL) have a weakened immune system. Infections acquired by these patients are cause for concern and especially worrisome when Gram-negative multidrug-resistant (MDR) bacteria are involved, as they are difficult to treat, especially in the case of ESBL- and/or carbapenemase-producing Enterobacterales. Culture-based approaches have been relied on over the past decades as the method of choice for the early detection of gut colonization by MDR Gram-negative bacteria. However, various studies have indicated its limited sensitivity, underlining the need for new screening procedures in onco-hematological patients. Here, we evaluated a shotgun metagenomics approach to detect ESBL- and/or carbapenemase-producing Enterobacterales in the gut of 28 patients who had recovered from AL, which were previously colonized by these bacteria but cured at the time of sampling, as judged by culture-based methods. No ESBL or carbapenemase determinants were detected among the many resistance genes found by the metagenomics approach, supporting that patients were truly decolonized, with considerable consequences for their future clinical management. Due to the relatively low number of patients available for the present investigation, further studies should be conducted to support the utility and applicability of metagenomics for the routine screening of MDR bacteria in onco-hematological patients.

Antimicrobial Stewardship Interventions in Pediatric Oncology: A Systematic Review

Antimicrobial stewardship programs represent efficacious measures for reducing antibiotic overuse and improving outcomes in different settings. Specific data on pediatric oncology are lacking. We conducted a systematic review on the PubMed and Trip databases according to the PRISMA guidelines, searching for reports regarding antimicrobial stewardship in pediatric oncology and hematology patients. The aim of the study was to summarize the present literature regarding the implementation of antimicrobial stewardship programs or initiatives in this particular population, and provide insights for future investigations. Nine papers were included in the qualitative analysis: three regarding antifungal interventions, five regarding antibacterial interventions, and one regarding both antifungal and antibacterial stewardship interventions. Variable strategies were reported among the included studies. Different parameters were used to evaluate the impact of these interventions, including days of therapy per 1000-patient-days, infections with resistant strains, safety analysis, and costs. We generally observed a reduction in the prescription of broad-spectrum antibiotics and an improved appropriateness, with reduced antibiotic-related side effects and no difference in infection-related mortality. Antibiotic stewardship programs or interventions are effective in reducing antibiotic consumption and improving outcomes in pediatric oncology hematology settings, although stewardship strategies differ substantially in different institutions. A standardized approach needs to be implemented in future studies in order to better elucidate the impact of stewardship programs in this category of patients.

Infection prevention requirements for the medical care of immunosuppressed patients: recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

In Germany, guidelines for hygiene in hospitals are given in form of recommendations by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, "KRINKO"). The KRINKO and its voluntary work are legitimized by the mandate according to § 23 of the Infection Protection Act (Infektionsschutzgesetz, "IfSG"). The original German version of this document was published in February 2021 and has now been made available to the international professional public in English. The guideline provides recommendations on infection prevention and control for immunocompromised individuals in health care facilities. This recommendation addresses not only measures related to direct medical care of immunocompromised patients, but also management aspects such as surveillance, screening, antibiotic stewardship, and technical/structural aspects such as patient rooms, air quality, and special measures during renovations.

Late effects of cancer in children, teenagers and young adults: Population-based study on the burden of 183 conditions, in-patient and critical care admissions and years of life lost

BACKGROUND

Children, teenagers and young adults who survived cancer are prone to developing late effects. The burden of late effects across a large number of conditions, in-patient hospitalisation and critical care admissions have not been described using a population-based dataset. We aim to systematically quantify the cumulative burden of late effects across all cancer subtypes, treatment modalities and chemotherapy drug classes.

METHODS

We employed primary care records linked to hospitals, the death registry and cancer registry from 1998-2020. CTYA survivors were 25 years or younger at the time of cancer diagnosis had survived ≥5 years post-diagnosis. Year-of-birth and sex-matched community controls were used for comparison. We considered nine treatment types, nine chemotherapy classes and 183 physical and mental health late effects. Cumulative burden was estimated using mean cumulative count, which considers recurring events. Multivariable logistic regression was used to investigate the association between treatment exposures and late effects. Excess years of life lost (YLL) attributable to late effects were estimated.

FINDINGS

Among 4,063 patients diagnosed with cancer, 3,466 survived ≥ 5 years (85%); 13,517 matched controls were identified. The cumulative burden of late effects at age 35 was the highest in survivors of leukaemia (23.52 per individual [95% CI:19.85-29.33]) and lowest in survivors of germ cell tumours (CI:6.04 [5.32-6.91]). In controls, the cumulative burden was 3.99 (CI:3.93-4.08) at age 35 years. When survivors reach age 45, the cumulative burden for immunological conditions and infections was the highest (3.27 [CI:3.01-3.58]), followed by cardiovascular conditions (3.08 [CI:1.98-3.29]). Survivors who received chemotherapy and radiotherapy had the highest disease burden compared to those who received surgery only. These patients also had the highest burden of hospitalisation (by age 45: 10.43 [CI:8.27-11.95]). Survivors who received antimetabolite chemotherapy had the highest disease and hospitalisation burden, while the lowest burden is observed in those receiving antitumour antibiotics. Regression analyses revealed that survivors who received only surgery had lower odds of developing cardiovascular (adjusted odds ratio 0.73 [CI:0.56-0.94]), haematological (aOR 0.51 [CI:0.37-0.70]), immunology and infection (aOR 0.84 [CI:0.71-0.99]) and renal (aOR 0.51 [CI:0.39-0.66]) late effects. By contrast, the opposite trend was observed in survivors who received chemo-radiotherapy. High antimetabolite chemotherapy cumulative dose was associated with increased risks of subsequent cancer (aOR 2.32 [CI:1.06-4.84]), metastatic cancer (aOR 4.44 [CI:1.29-11.66]) and renal (aOR 3.48 [CI:1.36-7.86]) conditions. Patients who received radiation dose of ≥50 Gy experienced higher risks of developing metastatic cancer (aOR 5.51 [CI:2.21-11.86]), cancer (aOR 3.77 [CI:2.22-6.34]), haematological (aOR 3.43 [CI:1.54-6.83]) and neurological (aOR 3.24 [CI:1.78-5.66]) conditions. Similar trends were observed in survivors who received more than three teletherapy fields. Cumulative burden analyses on 183 conditions separately revealed varying dominance of different late effects across cancer types, socioeconomic deprivation and treatment modalities. Late effects are associated with excess YLL (i.e., the difference in YLL between survivors with or without late effects), which was the most pronounced among survivors with haematological comorbidities.

INTERPRETATION

To our knowledge, this is the first study to dissect and quantify the importance of late morbidities on subsequent survival using linked electronic health records from multiple settings. The burden of late effects is heterogeneous, as is the risk of premature mortality associated with late effects. We provide an extensive knowledgebase to help inform treatment decisions at the point of diagnosis, future interventional trials and late-effects screening centred on the holistic needs of this vulnerable population.

Chemotherapy for Childhood Acute Myeloid Leukemia and Associated Infections Over Two Decades in India: Timeline and Impact on Outcome

Background: Infection and relapse constitute the two main challenges in the management of acute myeloid leukemia (AML) in children. Real-world data in children treated in low-and-middle income countries are sparse as the cost of supportive care is high. Patients and Methods: We present data on children up to 18 years of age undergoing chemotherapy for AML as per UKMRC AML protocol from 2002 to June 2019 and pattern of sepsis. Results: The incidence of culture-positive sepsis was similar pre- and post-2012 (52.6% vs. 72.4%), Klebsiella pneumoniae being the most common organism. There was a significant increase in carbapenem resistance post 2012 (14% vs. 67%, P = 0.032). Sepsis-related induction mortality has remained at 6.2% despite an increase in drug-resistant bacterial infections over two decades. The overall survival was 53% (n=48), with a plateau in the survival curve after 24 months, relapse being the most common cause of death (69%). Conclusions: Sepsis-related induction mortality can be maintained at less than 10% in children undergoing chemotherapy for AML, despite increasing drug-resistant bacteremia, with adequate supportive care and trained personnel including pediatric intensivists and nurses.

Quality of inpatient antimicrobial use in hematology and oncology patients

OBJECTIVES

To compare antimicrobial prescribing practices in Australian hematology and oncology patients to noncancer acute inpatients and to identify targets for stewardship interventions.

DESIGN

Retrospective comparative analysis of a national prospectively collected database.

METHODS

Using data from the 2014-2018 annual Australian point-prevalence surveys of antimicrobial prescribing in hospitalized patients (ie, Hospital National Antimicrobial Prescribing Survey called Hospital NAPS), the most frequently used antimicrobials, their appropriateness, and guideline concordance were compared among hematology/bone marrow transplant (hemBMT), oncology, and noncancer inpatients in the setting of treatment of neutropenic fever and antibacterial and antifungal prophylaxis.

RESULTS

In 454 facilities, 94,226 antibiotic prescriptions for 62,607 adult inpatients (2,230 hemBMT, 1,824 oncology, and 58,553 noncancer) were analyzed. Appropriateness was high for neutropenic fever management across groups (83.4%-90.4%); however, hemBMT patients had high rates of carbapenem use (111 of 746 prescriptions, 14.9%), and 20.2% of these prescriptions were deemed inappropriate. Logistic regression demonstrated that hemBMT patients were more likely to receive appropriate antifungal prophylaxis compared to oncology and noncancer patients (adjusted OR, 5.3; P < .001 for hemBMT compared to noncancer patients). Oncology had a low rate of antifungal prophylaxis guideline compliance (67.2%), and incorrect dosage and frequency were key factors. Compared to oncology patients, hemBMT patients were more likely to receive appropriate nonsurgical antibacterial prophylaxis (aOR, 8.4; 95% CI, 5.3-13.3; P < .001). HemBMT patients were also more likely to receive appropriate nonsurgical antibacterial prophylaxis compared to noncancer patients (OR, 3.1; 95% CI, 1.9-5.0; P < .001). However, in the Australian context, the hemBMT group had higher than expected use of fluoroquinolone prophylaxis (66 of 831 prescriptions, 8%).

CONCLUSIONS

This study demonstrates why separate analysis of hemBMT and oncology populations is necessary to identify specific opportunities for quality improvement in each patient group.

The democratization of de-labeling: a review of direct oral challenge in adults with low-risk penicillin allergy

INTRODUCTION

Penicillin antibiotic allergy labels (AALs) are common and lead to significant negative health and health system outcomes. Direct oral challenge offers a rapid and cost-effective way of removing inaccurate AALs and improving outcomes.

AREAS COVERED

A narrative review (Medline, May 2020) of direct oral challenge in low-risk penicillin allergy in adults is described, and the evidence for the safety and efficacy of this approach in inpatients, outpatients, and special patient groups is presented.

EXPERT OPINION

Whilst the current literature demonstrates the safety and efficacy of direct oral challenge in de-labeling low-risk penicillin allergy in adults, novel approaches are needed to improve access to antibiotic allergy assessment and address the growing global need.

Infections Due to Carbapenem-Resistant Bacteria in Patients With Hematologic Malignancies

In developed countries, hematological malignancies (HM) account for 8 to 10% of cancers diagnosed annually and one-third of patients with HM (HMP) are expected to die from their disease. The former wide spectrum “magic bullet,” imipenem, has been ousted by the emergence of carbapenem resistant (CR) pathogens. In endemic areas, infections with CR-bacteria occur in vulnerable patients, notably in HMP, who suffer from high mortality related to infectious complications. In this work, we reviewed epidemiologic and clinical factors associated with CR-infections in adult HMP and data on CR-related mortality and antibiotic treatments in this population. We found that resistance profile of strains involved in HMP infections, mainly bacteremia, reflect local epidemiology. Significant risk factors for infections with CR-bacteria include sex male, age around 50 years old, acute leukemia, selvage chemotherapy, neutropenia, and digestive colonization by CR-bacteria. Mortality rate is high in HMP infected with CR-Enterobacteriaceae, more particularly in case of acute myeloid leukemia and unresolved neutropenia, due to inappropriate empiric management and delayed administration of targeted antibiotics, such as tigecycline, colistin, or new associations of active drugs. Thus, we developed an algorithm for clinicians, assessing the incremental risk for CR-bacterial infection occurrence and mortality in febrile HMP, to guide decisions related to empirical therapeutic strategies.

Genomic characterization of Citrobacter freundii strains coproducing OXA-48 and VIM-1 carbapenemase enzymes isolated in leukemic patient in Spain

Background

The emergence of carbapenemase-producing (CP) Citrobacter freundii poses a significant threat to public health, especially in high-risk populations. In this study, whole genome sequencing was used to characterize the carbapenem resistance mechanism of three C. freundii clinical isolates recovered from fecal samples of patients with acute leukemia (AL) from Spain.

Materials and methods

Twelve fecal samples, collected between 2013 and 2015 from 9 patients with AL, were screened for the presence of CP strains by selecting them on MacConkey agar supplemented with ertapenem (0.5 mg/L). Bacteria were identified by MALDI-TOF mass spectrometry and were phenotypically characterized. Whole genome sequencing of C. freundii isolates was performed using the MinION and MiSeq Illumina sequencers. Bioinformatic analysis was performed in order to identify the molecular support of carbapenem resistance and to study the genetic environment of carbapenem resistance encoding genes.

Results

Three carbapenem-resistant C. freundii strains (imipenem MIC≥32 mg/L) corresponding to three different AL patients were isolated. Positive modified Carba NP test results suggested carbapenemase production. The genomes of each C. freundii tested were assembled into a single chromosomal contig and plasmids contig. In all the strains, the carbapenem resistance was due to the coproduction of OXA-48 and VIM-1 enzymes encoded by genes located on chromosome and on an IncHI2 plasmid, respectively. According to the MLST and the SNPs analysis, all strains belonged to the same clone ST169.

Conclusion

We report in our study, the intestinal carrying of C. freundii clone ST169 coproducing OXA-48 and VIM-1 identified in leukemic patients.

The Impact of Reported Beta-Lactam Allergy in Hospitalized Patients With Hematologic Malignancies Requiring Antibiotics

Background

Patients hospitalized with hematologic malignancy are particularly vulnerable to infection. The impact of reported beta-lactam (BL) allergy in this population remains unknown.

Methods

This was a retrospective cohort study of adult inpatients with hematologic malignancy admitted at 2 tertiary care hospitals from 2010 through 2015. The primary outcome was hospital length of stay (LOS) after administration of the first antibiotic. Secondary outcomes included readmission, mortality, complications, hospital charges, and antibiotic usage. Our goal was to define the impact of BL-only allergy (BLOA) label on clinical outcomes compared to those with no BL allergy (NBLA) in hematologic malignancy inpatients who required systemic antibiotics.

Results

In our cohort (n = 4671), 38.3% had leukemia, 4.9% had Hodgkin lymphoma, 36.1% had non-Hodgkin lymphoma, and 20.7% had multiple myeloma. Among patients, 35.1% reported antibiotic allergy, and 14.1% (n = 660) had BLOA (including 9.3% with penicillin-only allergy and 3.3% cephalosporin-only allergy). Patients with BLOA had longer median LOS compared to patients with NBLA (11.3 vs 7.6 days, P < .001), which remained significant after multivariable adjustment. Patients with BLOA also had significantly worse outcomes in terms of mortality rate at 30 days (7.6% vs 5.3%, P = .017) and 180 days (15.8% vs 12.2%, P = .013), 30-day readmission rate, Clostridium difficile rate, hospital charges ($223 046 vs $173 256, P < .001), antibiotic classes used, and antibiotic duration.

Conclusions

In hospitalized patients with hematologic malignancy, patients with reported BL allergy had worse clinical outcomes and higher healthcare cost than those without BL allergy label.

Clinical impact of an antimicrobial stewardship program on high-risk pediatric patients

OBJECTIVE

To evaluate the clinical impact of an antimicrobial stewardship program (ASP) on high-risk pediatric patients.

DESIGN

Retrospective cohort study.

SETTING

Free-standing pediatric hospital.

PATIENTS

This study included patients who received an ASP review between March 3, 2008, and March 2, 2017, and were considered high-risk, including patients receiving care by the neonatal intensive care (NICU), hematology/oncology (H/O), or pediatric intensive care (PICU) medical teams.

METHODS

The ASP recommendations included stopping antibiotics; modifying antibiotic type, dose, or duration; or obtaining an infectious diseases consultation. The outcomes evaluated in all high-risk patients with ASP recommendations were (1) hospital-acquired Clostridium difficile infection, (2) mortality, and (3) 30-day readmission. Subanalyses were conducted to evaluate hospital length of stay (LOS) and tracheitis treatment failure. Multivariable generalized linear models were performed to examine the relationship between ASP recommendations and each outcome after adjusting for clinical service and indication for treatment.

RESULTS

The ASP made 2,088 recommendations, and 50% of these recommendations were to stop antibiotics. Recommendation agreement occurred in 70% of these cases. Agreement with an ASP recommendation was not associated with higher odds of mortality or hospital readmission. Patients with a single ASP review and agreed upon recommendation had a shorter median LOS (10.2 days vs 13.2 days; P &lt; .05). The ASP recommendations were not associated with high rates of tracheitis treatment failure.

CONCLUSIONS

ASP recommendations do not result in worse clinical outcomes among high-risk pediatric patients. Most ASP recommendations are to stop or to narrow antimicrobial therapy. Further work is needed to enhance stewardship efforts in high-risk pediatric patients.

Beta-Lactam and Sulfonamide Allergy Testing Should Be a Standard of Care in Immunocompromised Hosts

Antibiotic allergies are reported in up to 1 in 4 immunocompromised hosts with significant impacts on antibiotic utilization and patient outcomes. Health services programs focused on de-labeling beta-lactam and sulfonamide allergy labels should be a standard of care in immunocompromised hosts.

Detection of plasmid-mediated colistin resistance, mcr-1 gene, in Escherichia coli isolated from high-risk patients with acute leukemia in Spain

BACKGROUND

Bacterial infections in immunocompromised patients are associated with a high mortality and morbidity rate. In this high-risk group, the presence of multidrug-resistant (MDR) bacteria, particularly bacteria that harbor a transferable antibiotic resistance gene, complicates the management of bacterial infections. In this study, we investigated the presence of the transferable colistin resistance mcr genes in patients with leukemia in Spain.

METHODS

217 fecal samples collected in 2013-2015 from 56 patients with acute leukemia and colonized with MDR Enterobacteriaceae strains, were screened on September 2017 for the presence of the colistin resistance mcr genes (mcr-1 to -5) by multiplex PCR. mcr positive strains selected on LBJMR and MacConkey supplemented with colistin (2 μg/ml) media were phenotypically and molecularly characterized by antimicrobial susceptibility testing, minimum inhibitory concentration, multilocus sequence typing and plasmid characterization.

RESULTS

Among 217 fecal samples, 5 samples collected from 3 patients were positive for the presence of the mcr-1 colistin-resistance gene. Four Escherichia coli strains were isolated and exhibited resistance to colistin with MIC = 4 μg/ml. Other genes conferring the resistance to β-lactam antibiotics have also been identified in mcr-1 positive strains, including bla_TEM-206 and bla_TEM-98. Three different sequence types were identified, including ST1196, ST140 and ST10. Plasmid characterization allowed us to detect the mcr-1 colistin resistance gene on conjugative IncP plasmid type.

CONCLUSION

To the best of our knowledge, we have identified the mcr-1 gene for the first time in leukemia patients in Spain. In light of these results, strict measures have been implemented to prevent its dissemination.

Update on infection control practices in cancer hospitals

Therapies in oncology have evolved rapidly over the last years. At the same pace, supportive care for patients receiving cancer therapy has also evolved, allowing patients to safely receive the newest advances in treatment in both an inpatient and outpatient basis. The recognition of the role of infection control and prevention (ICP) in the outcomes of patients living with cancer has been such that it is now a requirement for hospitals and involves multidisciplinary groups. Some unique aspects of ICP for patients with cancer that have gained momentum over the past few decades include catheter-related infections, multidrug-resistant organisms, community-acquired viral infections, and the impact of the health care environment on the horizontal transmission of organisms. Furthermore, as the potential for infections to cross international borders has increased, alertness for outbreaks or new infections that occur outside the area have become constant. As the future approaches, ICP in immunocompromised hosts will continue to integrate emerging disciplines, such as antibiotic stewardship and the microbiome, and new techniques for environmental cleaning and for controlling the spread of infections, such as whole-genome sequencing. CA Cancer J Clin 2018;000:000-000. © 2018 American Cancer Society.

Population pharmacokinetics and dosing considerations for the use of daptomycin in adult patients with haematological malignancies

Objectives

To assess the population pharmacokinetics (popPK) of daptomycin at the conventional dose of 6 mg/kg/day in a cohort of oncohaematological patients.

Methods

Patients underwent serial blood sampling on day 3 of therapy (before dosing and at 0, 0.5, 1, 2, 3, 5, 7, 9 and 12 h after dosing) to assess the pharmacokinetic profile of daptomycin. PopPK and Monte Carlo simulation were performed to define the probability of target attainment (PTA) with 6, 8, 10 and 12 mg/kg/day of the pharmacokinetic/pharmacodynamic target of AUC 24 /MIC >1081.

Results

Thirty patients were recruited. A two-compartment open model with first-order intravenous input and first-order elimination was developed. Estimated creatinine clearance (CL CR ), serum albumin concentration (Alb) and presence of AML were covariates included in the final model. Monte Carlo simulation showed that the conventional 6 mg/kg/day dose resulted in optimal PTAs (≥80%) in the presence of pathogens with an MIC up to 0.5 mg/L only in patients with CL CR 50-100 mL/min/1.73 m 2 , Alb 26-45 g/L and a haematological diagnosis other than AML. Conversely, higher dosages, up to 12 mg/kg/day, were needed to achieve this goal in the presence of pathogens with an MIC of 0.25-0.5 mg/L in all of the other tested scenarios. In patients with CL CR 101-150 mL/min/1.73 m 2 and Alb 15-25 g/L, suboptimal PTAs (<60%) were predicted even with 12 mg/kg/day dosing .

Conclusions

Our study provides a strong rationale for considering daptomycin dosages of ≥ 8 mg/kg/day in several clinical scenarios for oncohaematological patients. In some of these scenarios therapeutic drug monitoring could be a useful adjunct for optimized care.

Pediatric Patients With Solid or Hematological Tumor Disease: Vancomycin Population Pharmacokinetics and Dosage Optimization

BACKGROUND

In pediatric cancer patients, determination of optimal vancomycin dosage is essential because of high risk of inadequate concentrations and bacterial resistance. The aim of this study was to determine vancomycin pharmacokinetic parameters in this population and propose dosage optimization to achieve optimal concentration.

METHODS

We retrospectively reviewed the use of vancomycin in pediatric cancer patients with febrile neutropenia (hematological or solid tumor disease). Vancomycin was administered by continuous infusion, and dosages were adapted according to therapeutic drug monitoring results. Blood cultures were performed before the first dose of antibiotic. Vancomycin pharmacokinetic population parameters were determined using NONMEM software, and dosage simulations were performed according to the target concentration (20-25 mg/L).

RESULTS

One hundred twenty-one patients were included in this study, representing 301 vancomycin concentrations. Blood cultures were positive in 37.5% of patients, and observed pathogens were mainly Staphylococcus spp. (43.8% methicillin resistant). Volume of distribution (95% confidence interval) was 34.7 L (17.3-48.0), and total apparent clearance (CL) (95% confidence interval) was correlated to body weight, tumor disease, and cyclosporine coadministration: CL = θCL × (WT/70) L/h with θCL = 3.49 (3.02-3.96), 4.66 (3.98-5.31), and 4.97 (4.42-5.41) in patients managed for hematological malignancies with or without cyclosporine coadministration and for solid malignancies, respectively. Based on simulation results, vancomycin dosage (milligram per kilogram) should be adapted to each child on the basis of its body weight and cyclosporine coadministration.

CONCLUSIONS

Our results highlight the requirement to adapt vancomycin dosage in cancer pediatric population. Simulations have allowed to describe new dosage schedules, and a chart was created for clinicians to adapt vancomycin dosage.

Optimizing Symptoms and Management of Febrile Neutropenia among Cancer Patients: Current Status and Future Directions

Febrile neutropenia (FN) is a common and serious complication among cancer patients undergoing myelosuppressive chemotherapy. FN should be treated as a medical emergency because it can lead to life-threatening complications if appropriate treatment is not initiated immediately. This study provides a critical review on the current management of FN and identifies possible directions to optimize FN management.

Low rates of antibiotic resistance and infectious mortality in a cohort of high-risk hematology patients: A single center, retrospective analysis of blood stream infection

Febrile neutropenia (FN) is a medical emergency and can represent a life-threatening complication for hematology patients treated with intensive chemotherapy regimens. In clinical practice, the diagnostic yield of blood cultures and other investigations which aim to identify a causative organism or site of infection is low. We have retrospectively examined all blood cultures collected in a “real world” cohort of patients receiving chemotherapy for acute leukemia and patients with aggressive lymphoma treated with Hyper-CVAD/MTX-cytarabine, at a single tertiary center over a five-year period. In this cohort, the 30-day mortality following confirmed blood stream infection (BSI) was 5.9%, which is lower than most reports in the recent literature. We compared the blood culture results of inpatients undergoing induction chemotherapy and outpatients presenting with fevers and found a significantly higher rate of proven BSI in the outpatient group. In all settings, gram-negative organisms were most common. The rate of resistance to first-line empiric antibiotics among pathogenic isolates was 11.6% in the whole cohort, independent of blood culture circumstances. There was a trend to higher resistance rates among inpatients undergoing induction chemotherapy compared to patients presenting to the emergency department (17.4% vs 7.5%) but this did not reach statistical significance. We also report low rates of ciprofloxacin resistance (5% of isolates), in a center where universal fluoroquinolone prophylaxis is not employed. Our low resistance and mortality rates support our current therapeutic strategies, however presence of resistant organisms across the spectrum of indications for BC collection highlights the importance of surveilling local patterns, escalating antimicrobial therapy in the deteriorating patient, and considering advanced techniques for the rapid identification of resistance in this patient population.

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.

Antibacterial Resistance in Patients with Hematopoietic Stem Cell Transplantation

Recipients of hematopoietic stem cell transplantation (HSCT) are at substantial risk of bacterial, fungal, viral, and parasitic infections depending on the time elapsed since transplantation, presence of graft-versus-host disease (GVHD), and the degree of immunosuppression. Infectious complications in HSCT recipients are associated with high morbidity and mortality. Bacterial infections constitute the major cause of infectious complications, especially in the early post-transplant period. The emergence of antibacterial resistance complicates the management of bacterial infections in this patient group. Multidrug-resistant bacterial infections in this group of patients have attracted considerable interest and may lead to significant morbidity and mortality. Empirical antibacterial therapy in patients with HSCT and febrile neutropenia has a critical role for survival and should be based on local epidemiology. This review attempts to provide an overview of risk factors and epidemiology of emerging resistant bacterial infections and their management in HSCT recipients.

The growing threat of multidrug-resistant Gram-negative infections in patients with hematologic malignancies

Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine the infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess the strategies to improve outcomes of the infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam.

The epidemiology of Clostridium difficile infection in patients with cancer

INTRODUCTION

Clostridium difficile infection (CDI) is a significant cause of healthcare-associated diarrhoea, and the emergence of endemic strains resulting in poorer outcomes is recognised worldwide. Patients with cancer are a specific high-risk group for development of infection. Areas covered: In this review, modifiable and non-modifiable risk factors for CDI in adult patients with haematological malignancy or solid tumours are evaluated. In particular, the contribution of antimicrobial exposure, hospitalisation and gastric acid suppression to risk of CDI are discussed. Recent advances in CDI treatment are outlined, namely faecal microbiota transplantation and fidaxomicin therapy for severe/refractory infection in cancer populations. Outcomes of CDI, including mortality are presented, together with the need for valid severity rating tools customised for cancer populations. Expert commentary: Future areas for research include the prognostic value of C. difficile colonisation in cancer patients and the potential impact of dedicated antimicrobial stewardship programs in reducing the burden of CDI in cancer units.

Can mortality of cancer patients with fever and neutropenia be improved?

PURPOSE OF REVIEW

Neutropenic fever is the most common infective complication in patients receiving cytotoxic chemotherapy, and may result in severe sepsis, septic shock and mortality. Advancements in approaches to empiric antimicrobial therapy and prophylaxis have resulted in improved outcomes. Mortality may, however, still be as high as 50% in high-risk cancer populations. The objective of this review is to summarize factors associated with reduced mortality in patients with neutropenic fever, highlighting components of clinical care with potential for inclusion in quality improvement programs.

RECENT FINDINGS

Risks for mortality are multifactorial, and include patient, disease and treatment-related factors. Historically, guidelines for management of neutropenic fever have focused upon antimicrobial therapy. There is, however, a recognized need for early identification of sepsis to enable timely administration of antibiotic therapy and for this to be integrated with a whole of systems approach within healthcare facilities. Use of Systemic Inflammatory Response Syndrome criteria is beneficial, but validation is required in neutropenic fever populations.

SUMMARY

In the context of emerging and increasing infections because of antimicrobial-resistant bacteria in patients with neutropenic fever, quality improvement initiatives to reduce mortality must encompass antimicrobial stewardship, early detection of sepsis, and use of valid tools for clinical assessment. C-reactive protein and procalcitonin hold potential for inclusion into clinical pathways for management of neutropenic fever.

Oral pristinamycin for the treatment of resistant Gram-positive infections in patients with cancer: Evaluation of clinical outcomes

Pristinamycin has been used to treat a range of Gram-positive infections, but reported experience in patients with malignancy is limited. This study aimed to evaluate the use of pristinamycin in patients with cancer at an Australian centre. All patients commenced on oral pristinamycin therapy at the Peter MacCallum Cancer Centre between January 2005 and December 2014 were identified using the hospital pharmacy dispensing system. Information on demographics, co-morbidities, cancer diagnosis, infection characteristics, pristinamycin regimen, pristinamycin tolerability and outcomes was collected. The median duration of follow-up was 398 days. In total, 26 patients received pristinamycin, with median age of 61 years and a male predominance (65%). Underlying diagnoses were haematological malignancies (50%) and solid tumours (50%). Pathogens included 13 meticillin-resistant Staphylococcus aureus, 6 vancomycin-resistant Enterococcus faecium, 4 meticillin-resistant Staphylococcus epidermidis, 2 meticillin-susceptible S. aureus and 1 vancomycin-susceptible E. faecium. Infection sites were osteomyelitis (6), skin and soft-tissue (4), intra-abdominal/pelvic abscess (4), bloodstream (3), empyema (3), endocarditis/endovascular (3), prosthesis-related infection (2) and epididymo-orchitis (1). One patient ceased pristinamycin due to nausea. Regarding outcome, 13 patients (50%) were cured of infection, 8 (31%) had suppression and 5 (19%) had relapse. Relapses included 1 endovascular infection, 2 episodes of osteomyelitis, 1 pelvic abscess and 1 skin and soft-tissue infection. Overall, 81% of patients achieved cure or suppression of antibiotic-resistant or complex Gram-positive infections, consistent with published experience in non-cancer populations. A favourable tolerability profile makes oral pristinamycin a viable treatment option, particularly in settings where outpatient management of cancer is the objective.

Management of fever and neutropenia in paediatric cancer patients: room for improvement?

PURPOSE OF REVIEW

Fever and neutropenia is the most common complication in the treatment of childhood cancer. This review will summarize recent publications that focus on improving the management of this condition as well as those that seek to optimize translational research efforts.

RECENT FINDINGS

A number of clinical decision rules are available to assist in the identification of low-risk fever and neutropenia however few have undergone external validation and formal impact analysis. Emerging evidence suggests acute fever and neutropenia management strategies should include time to antibiotic recommendations, and quality improvement initiatives have focused on eliminating barriers to early antibiotic administration. Despite reported increases in antimicrobial resistance, few studies have focused on the prediction, prevention, and optimal treatment of these infections and the effect on risk stratification remains unknown. A consensus guideline for paediatric fever and neutropenia research is now available and may help reduce some of the heterogeneity between studies that have previously limited the translation of evidence into clinical practice.

SUMMARY

Risk stratification is recommended for children with cancer and fever and neutropenia. Further research is required to quantify the overall impact of this approach and to refine exactly which children will benefit from early antibiotic administration as well as modifications to empiric regimens to cover antibiotic-resistant organisms.

Invasive gram-positive bacterial infection in cancer patients

Systematic studies have shown that gram-positive organisms are the leading cause of invasive bacterial disease in patients with cancer. A broad range of gram-positive bacteria cause serious infections in the cancer patient with the greatest burden of disease being due to staphylococci, streptococci, and enterococci. The evolution of cancer therapy and the changing epidemiology of major gram-positive pathogens mean that ongoing efforts are needed to understand and mitigate the impact of these bacteria in patients with malignancy. The development of novel antibacterials, optimization of treatment approaches, implementation of improved vaccines, and manipulation of the microbiome are all active areas of investigation in the goal of improving the survival of the cancer patient through amelioration of the disease burden of gram-positive bacteria.

The impact of antimicrobial allergy labels on antimicrobial usage in cancer patients

Background

Antibiotic allergy labels are associated with sub-optimal prescribing patterns and poorer clinical outcomes in non-cancer populations, but the effect of labelling on antimicrobial usage in patients with cancer is unknown.

Findings

A retrospective review of hospitalized patients admitted to the Peter MacCallum Cancer Centre (2010-2012) identified 23 % of cancer patients (n = 198) with an antimicrobial allergy label (AA). Comparison of those with an antimicrobial allergy label to those without demonstrated increased antibiotic use per admission (3 vs. 2, p = 0.01), increased fluoroquinolone use (11 % vs. 6 %, p < 0.05), increased antibiotic course duration (15 vs. 13 days, p = 0.09), higher readmission rates (53 % vs. 28 %, p < 0.001) and poorer concordance with prescribing guidelines (47 % vs. 91 %, p < 0.001). Patients in the AA group on multivariate analysis had a higher number of antibiotics employed, longer duration of antibiotic therapy and higher rate of readmission.

Conclusions

Antimicrobial usage, including the use of restricted antibiotics, is higher in patients with cancer. Antibiotic de-labelling strategies in cancer patients must be evaluated to aid antimicrobial stewardship initiatives.

Changing treatment paradigms for patients with plasma cell myeloma: impact upon immune determinants of infection

Plasma cell myeloma (PCM) is increasing in prevalence in older age groups and infective complications are a leading cause of mortality. Patients with PCM are at increased risk of severe infections, having deficits in many arms of the immune system due to disease and treatment-related factors. Treatment of PCM has evolved over time with significant impacts on immune function resulting in changing rates and pattern of infection. Recently, there has been a paradigm shift in the treatment of PCM with the use of immunomodulatory drugs and proteasome inhibitors becoming the standard of care. These drugs have wide-ranging effects on the immune system but their impact on infection risk and aetiology remain unclear. The aims of this review are to discuss the impact of patient, disease and treatment factors on immune function over time for patients with PCM and to correlate immune deficits with the incidence and aetiology of infections seen clinically in these patients. Preventative measures and the need for clinically relevant tools to enable infective profiling of patients with PCM are discussed.