Analysis of bacteremia at first-line antibiotic treatment for febrile neutropenia in children and adolescents: A retrospective, single-center analysis.

BACKGROUND: Control of bacterial and fungal infections is critical to improving outcomes in hematological neoplastic diseases of children and adolescents. In this study, a retrospective analysis of our previous studies on febrile neutropenia was performed to investigate bacteremia. PROCEDURE: From August 2008 to December 2023, five antibiotic studies were performed for febrile and neutropenic pediatric patients who had been treated with chemotherapy, immunosuppressive therapy, or had received stem cell transplantation in the pediatric unit at Sapporo Hokuyu Hospital. The rate of positive blood culture, detected bacteria, and susceptibility of several types of antibiotics in febrile episodes were investigated. RESULTS: Blood culture was positive in 133 of 1604 febrile episodes of 329 patients. Detected bacteria were Gram-positive cocci (61.2 %), Gram-negative bacilli (27.6 %), Gram-negative cocci (0.7 %), and Gram-positive bacilli (10.4 %). The incidence of bacteremia over time showed a decreasing trend with each passing year. In particular, the incidence of bacteremia was around 10 % in 2008-2013, whereas it was often below 5 % after 2020; this decrease was statistically significant. Although almost all detected bacteria and their susceptibilities to antibiotics (piperacillin/tazobactam, meropenem, ceftazidime, and cefozopran) did not change over time, all Escherichia coli detected after 2014 were extended-spectrum ß-lactamase-producing bacteria.

Cytokine and chemokine profiles in episodes of persistent high-risk febrile neutropenia in children with cancer.

BACKGROUND: In children with cancer and persistent high-risk febrile neutropenia (HRFN), cytokines/chemokines profiles can guide the differentiation of febrile neutropenia (FN) due to infections and episodes of unknown origin (FN-UO). METHODS: A prospective, multicenter study in Santiago, Chile included patients ≤ 18 years with cancer and HRFN. Clinical and microbiological studies were performed according to validated protocols. Serum levels of 38 cytokines/chemokines were determined on day 4 of persistent HRFN. We performed comparisons between i) HRFN episodes with a detected etiological agent (FN-DEA) and FN-UO, and ii) bacterial versus viral infections. ROC curves were used to assess the discriminatory power of the analytes. RESULTS: 110 HRFN episodes were enrolled (median age 8 years, 53% female). Eighty-four patients were FN-DEA: 44 bacterial, 32 viral, and 8 fungal infections. Twenty-six cases were categorized as FN-UO. Both groups presented similar clinical and laboratory characteristics. Nineteen out of 38 analytes had higher concentrations in the FN-DEA versus FN-UO group. G-CSF, IL-6, and Flt-3L showed the highest discriminatory power to detect infection (AUC 0.763, 0.741, 0.701). Serum levels of G-CSF differentiated bacterial infections and IP-10 viral agents. A combination of G-CSF, IL-6, Flt-3L, and IP-10 showed an AUC of 0.839, 75% sensitivity, and 81% specificity. CONCLUSION: A specific immune response is present on day four of persistent HRFN in children with cancer. We propose a combined measure of serum concentrations of G-CSF, IL-6, IP-10, and Flt-3L, in order to predict the presence of an infectious agent as compared to an episode of FN with unknown origin.

The use of serum endothelial adhesion molecules in pediatric patients with leukemia with febrile neutropenia to predict bacteremia.

OBJECTIVE: Febrile neutropenia (FN) represents a life-threatening complication in hematological malignancies. We aimed to analyze the utility of soluble vascular cell adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1), vascular endothelial growth factor (VEGF) levels compared with C-reactive protein (CRP) and procalcitonin (PCT) during febrile neutropenia episodes of pediatric patients with leukemia. METHODS: Two plasma samples, on day 0 (initial of episode) and day 3 (48-72 h after episode), for VCAM-1, ICAM-1 and VEGF, CRP and PCT were prospectively collected concomitantly during each febrile neutropenic episode between December 2016 and December 2017. The primary outcome was bacteremia and the secondary outcome was intensive care unit (ICU) admission. RESULTS: Twenty-two (28.6%) acute lymphoblastic lymphoma (ALL), seventeen (22.1%) acute myeloblastic lymphoma (AML) patients and thirty-eight (49.3%) control patients with no known underlying disease or fever were included in this study. Of the 39 patients; 16 (41%) had bacteremia. Mean serum sVCAM1 and sICAM1 levels were significantly higher in control group, compared to FN patients (p < 0.001). Mean serum sVCAM2 level was significantly higher in FN patients with bacteremia compared to FN patients without bacteremia (144.97 ± 70.35 pg/mL vs 85.45 ± 53.76 pg/mL, p = 0.022). Mean sVCAM1 and 2 levels were higher in FN patients with ICU admission. In this study, we found that sVCAM-1 and VEGF, when combined to CRP and PCT, could predict gram-negative bacteremia in FN episodes of pediatric hematological malignancy. CONCLUSION: Serum endothelial adhesion molecules, excluding sVCAM-1, cannot predict bacteremia and ICU admission alone in FN patients; but may be associated with clinical outcome when used with PCT and CRP.

Analysis of blood stream infections, antibiograms and clinical outcomes in haematological patients with febrile neutropenia: data from a tertiary care haematology institute in India.

Timely administration of appropriate empirical antibiotics in febrile neutropenia is crucial for favourable patient outcomes. There are guidelines in place recommending such antibiotics. However, regional variations and local epidemiological data must be evaluated to tailor the antibiotics for best possible and rational use. In this study, we audited the clinical and microbiological data of febrile neutropenic episodes occurring at a tertiary care haematology institution. Three hundred and ninety-three febrile neutropenic episodes occurring in 123 patients over a 1-year period were analysed for microbial profile, sensitivity and resistance patterns, and finally clinical outcomes. Gram-negative bacilli (GNB) blood stream infections (46.9%) were more prevalent as compared to gram-positive infections (41.9%). Overall mortality due to complicated neutropenic sepsis was 19.5% (24/123 patients). Increased resistance to carbapenems, beta-lactam beta-lactamase inhibitor combinations, aminoglycosides, fluoroquinolones, and cephalosporins were observed. Cefepime and tigecycline resistance were seen in 20% and 15% GNB isolates, respectively. Chest was the most frequent focus of infection, and acute myeloid leukaemia (AML) was the most common underlying disorder which correlated with the likelihood of death (p < 0.01). Multidrug-resistant GNB (esp. Klebsiella sp.) are still most worrisome isolates in neutropenic patients. Single-agent cefepime or piperacillin-tazobactam/tigecycline combination may be considered empirical agents. Chest infections and AML were independent predictors of poor clinical outcome in neutropenic patients. Regular audit of infections and antibiotic susceptibility data is needed to improve clinical outcomes in patients with febrile neutropenia.

An eleven-year cohort of bloodstream infections in 552 febrile neutropenic patients: resistance profiles of Gram-negative bacteria as a predictor of mortality.

Antimicrobial stewardship is of major importance in patients with febrile neutropenia (FN). In this study, we aimed to investigate the trends in resistance and the relationship with mortality rates in patients with FN. The single-center surveillance data of inpatients with FN and diagnosed as microbiologically confirmed bloodstream infections (BSIs) between 2006 and 2016 were reviewed retrospectively. A total of 950 episodes in 552 patients with BSIs were analyzed. Of whom, 55.9% were male, the median age was 43 years, and 35.6% had acute myeloid leukemia. In total, 1016 microorganisms were isolated from blood cultures. Gram-negatives accounted for 42.4% (n = 403) of the episodes. Among Gram-negatives, Enterobacteriaceae accounted for 346 (86%) (E. coli, n = 197; 34% extended-spectrum ß-lactamases (ESBL) producers, and Klebsiella spp., n = 120; 48.3% ESBL producers). Also, 24 (20.0%) of Klebsiella spp. had carbapenemase activity. There were 6 (5.0%) colistin-resistant Klebsiella spp. Thirteen (26.5%) of Pseudomonas spp. and 17 (60.7%) of Acinetobacter spp. had carbapenemase activity. There were 2 (5.6%) colistin-resistant Acinetobacter spp. The 30-day mortality rates were 12.0%, 21.5%, 34.6%, and 29.0% in BSIs due to Gram-positive, Gram-negative bacterial, fungal, and polymicrobial etiology respectively (p = 0.001). BSIs with ESBL-producing (p = 0.001) isolates, carbapenem (p < 0.001), and colistin-resistant isolates (p < 0.001) were associated with increased mortality risk. The tremendous rise in resistance rates among Gram-negatives is dreadfully related to increasing mortality and leads to sharp shifts toward extreme restrictions of unnecessary antibiotic uses. Antimicrobial stewardship in patients with FN requires vigilance and tailoring of treatment upon local surveillance data.

Bloodstream infection by multidrug-resistant Streptococcus oralis in a leukemic patient with febrile neutropenia after hematopoietic stem cell transplantation.

We reported the case of a patient with leukemia who developed febrile neutropenia after hematopoietic stem cell transplantation. Blood culture results revealed the presence of Streptococcus oralis, while antimicrobial susceptibility testing showed the resistance to penicillin and cephem. Furthermore, isolates were not susceptible to either meropenem or daptomycin but not to vancomycin. S oralis is known to belong to Streptococcus mitis group and be a causative agent of bacteremia in the neutropenic patients, but multidrug resistance of S oralis is rare. Our findings suggest that we might pay attention to the emergence of the microorganisms acquiring multidrug resistance in neutropenic patients.

Clinical Profile and Microbiologic Spectrum of Febrile Neutropenic Episodes in Children With Severe Aplastic Anemia.

BACKGROUND: Febrile neutropenia (FN) is a common life-threatening complication in patients with severe aplastic anemia (SAA). However, few studies have examined the spectrum of infections in FN in patients with SAA, especially in children. Therefore, the current study was planned to study the clinicomicrobiologic profile of FN episodes in these children. MATERIALS AND METHODS: Data of 38 episodes of FN that occurred in 31 children with SAA from November 2015 to April 2017 were collected prospectively and analyzed. RESULTS: FN episodes occurred more frequently (54.8%) in patients on immunosuppressive therapy. Clinically documented infections accounted for 21 (55.26%) episodes, microbiologically documented infections for 15 (39.47%), bacteremia for 13 (34.21%), and invasive fungal diseases for 6 (15.78%) episodes. Among clinically documented infections, the lower respiratory tract was the commonest site in 23.68% episodes, followed by skin and soft tissue infections. No focus of infection could be identified in 12 (31.57%) episodes. Gram-negative bacteria (71.42%) were the predominant isolates (commonest Klebsiella pneumoniae) over Gram-positive bacteria (commonest coagulase-negative Staphylococcus). High prevalence of aminoglycoside, piperacillin-tazobactam, and carbapenem resistance was noted among Gram-negative organisms. Gram-positive organisms showed excellent sensitivity to vancomycin, linezolid, and clindamycin. The overall mortality rate was 42%. CONCLUSIONS: Empirical antimicrobial therapy should include adequate coverage for Gram-negative pathogens. The antimicrobial regimen should be modified according to the results of the culture and sensitivity testing.

Is current initial empirical antibiotherapy appropriate to treat bloodstream infections in short-duration chemo-induced febrile neutropenia?

INTRODUCTION: Fever of unknown origin is by far the most common diagnosis in low-risk febrile neutropenic patients undergoing chemotherapy. The current empirical regimen combines amoxicillin-clavulanic acid and fluoroquinolones in low-risk neutropenic patients. The aim of this study was to assess the appropriateness of antibiotherapy and the outcome of bloodstream infections (BSI) in patients with expected neutropenia of short duration. METHODS: This 2-year monocentric retrospective study included all consecutive neutropenic febrile adult patients with expected duration of neutropenia ≤ 7 days. They were classified into low- and high-risk groups for complications using the MASCC index. Appropriateness of initial empirical antibiotic regimen was assessed for each BSI. Multivariate analysis was performed to identify factors associated with mortality. RESULTS: Over the study period, 189 febrile episodes with positive blood cultures in neutropenic patients were reported, of which 44 occurred during expected duration of neutropenia ≤ 7 days. Patients were classified as high-risk (n = 27) and low-risk (n = 17). Gram-negative bacteria BSI represented 57% of cases, including only two multidrug-resistant bacteria in high-risk patients. Initial empirical antibiotherapy was appropriate in 86% of cases, and inappropriate in the event of coagulase-negative Staphylococcus BSI (14%), although the outcome was always favorable. In low-risk patients, no deaths and only 12% of severe complications were reported, contrasting with mortality and complication rates of 48% (p < 0.001) and 63% in high-risk patients (p < 0.001), respectively. CONCLUSIONS: Outcome of BSI is favorable in low-risk febrile neutropenic patients, even with inappropriate empirical initial antibiotic regimen for coagulase-negative Staphylococcus BSI. Initial in-hospital assessment and close monitoring of these patients are however mandatory.

Detection of bacteria in blood circulation in patients receiving cancer chemotherapy.

INTRODUCTION: Bacterial translocation, in which intestinal bacteria pass through the intestinal wall, enter the blood circulation, and spread to other sites of the body, is thought to cause bacteremia and sometimes febrile neutropenia (FN) in patients who receive cancer chemotherapy. MATERIALS AND METHODS: We collected blood samples from 39 patients with various cancers at baseline and after chemotherapy began (during chemotherapy) and explored how frequently bacteria could be detected in the blood using a highly-sensitive, bacterial rRNA-targeted reverse transcription quantitative polymerase chain reaction (PCR) assay. RESULTS: Bacterial traces, typically Escherichia coli and Enterobacter spp., were detected in 10 patients (25.6%) at baseline and 11 patients (28.2%) during chemotherapy. The bacterial traces were positive either at baseline or during chemotherapy in 3 (60%) of 5 patients who had FN, and 6 (46%) of 13 patients aged 65 years or older. CONCLUSION: These findings support the notion that bacterial translocation occurs in patients with cancer regardless of whether they receive chemotherapy and can lead to the development of FN and other treatment-related infections.

The Feasibility of Host Transcriptome Profiling as a Diagnostic Tool for Microbial Etiology in Childhood Cancer Patients with Febrile Neutropenia.

Infection is a common and serious complication of cancer treatment in children that often presents as febrile neutropenia (FN). Gene-expression profiling techniques can reveal transcriptional signatures that discriminate between viral, bacterial and asymptomatic infections in otherwise healthy children. Here, we examined whether gene-expression profiling was feasible in children with FN who were undergoing cancer treatment. The blood transcriptome of the children (n = 63) was investigated at time of FN diagnosed as viral, bacterial, co-infection or unknown etiology, respectively, and compared to control samples derived from 12 of the patients following the FN episode. RNA sequencing was successful in 43 (68%) of the FN episodes. Only two genes were significantly differentially expressed in the bacterial versus the control group. Significantly up-regulated genes in patients with the other three etiologies versus the control group were enriched with cellular processes related to proliferation and cellular stress response, with no clear enrichment with innate responses to pathogens. Among the significantly down-regulated genes, a few clustered into pathways connected to responses to infection. In the present study of children during cancer treatment, the blood transcriptome was not suitable for determining the etiology of FN because of too few circulating immune cells for reliable gene expression analysis.

Impact of Preemptive Granulocyte Infusions During Febrile Neutropenia in Patients Colonized with Carbapenem-Resistant Gram-Negative Bacteria Undergoing Haploidentical Transplantation.

We prospectively studied the impact of preemptive granulocyte infusions (pGIs) in 69 patients colonized with carbapenem-resistant gram-negative bacteria (CRGNB) undergoing haploidentical hematopoietic cell transplantation (HCT) compared with a previous cohort of 33 patients who received only antimicrobials directed toward CRGNB at the onset of neutropenic fever (non-pGI group). All patients developed neutropenic fever at a median of day +8 (range, -4 to +12) after transplantation. Engraftment kinetics were similar for both groups. The median number of GIs was 2 (range, 1 to 7), and the median dose of granulocytes infused was 5 × 1010 granulocytes per infusion (range, 1 to 30). The overall incidence of CRGNB bloodstream infections (BSIs) was 21.2% in non-pGI group (7/33) and 17.5% (12/69) in the pGI group (P = .8). However, the CRGNB-related mortality among those with BSI was 100% (7/7) in the non-pGI group versus 16.6% (2/12) in the pGI group (P = .001). The day 100 (4.4% versus 24.4%, P = .002) and 2-year nonrelapse mortality (7.5% versus 35.6%, P = .0001) were significantly reduced in the pGI group. The overall survival at 2 years was 75.6% in the pGI group versus 21.2% in the non-pGI group (P = .0001). Colonization and subsequent BSI with CRGNB are associated with a high incidence of mortality in patients undergoing HCT. pGI reduced early mortality associated with CRGNB in colonized patients undergoing post-transplant cyclophosphamide-based haploidentical HCT.

Analyzing the capability of PSP, PCT and sCD25 to support the diagnosis of infection in cancer patients with febrile neutropenia.

Background Early diagnosis of infection is essential for the initial management of cancer patients with chemotherapy-associated febrile neutropenia (FN). In this study, we have evaluated two emerging infection biomarkers, pancreatic stone protein (PSP) and soluble receptor of interleukin 2, known as soluble cluster of differentiation 25 (sCD25), for the detection of an infectious cause in FN, in comparison with other commonly used infection biomarkers, such as procalcitonin (PCT). Methods A total of 105 cancer patients presenting to the emergency department were prospectively enrolled. We observed 114 episodes of chemotherapy-associated FN. At presentation, a blood sample was collected for the measurement of PCT, PSP and sCD25. In order to evaluate the discriminatory ability of these markers for the diagnosis of infection, the area under the curve (AUC) of the receiver operating characteristic curves was calculated. Results Infection was documented in 59 FN episodes. PCT, PSP and sCD25 levels were significantly higher in infected patients. PCT was the biomarker with the highest diagnostic accuracy for infection (AUC: 0.901), whereas PSP and sCD25 showed a similar performance, with AUCs of 0.751 and 0.730, respectively. In a multivariable analysis, PCT and sCD25 were shown to be independently associated with infection. Conclusions Two novel biomarkers, PSP and sCD25, correlated with infection in cancer patients with chemotherapy-associated FN, but neither PSP nor sCD25 improved the performance of PCT. Based on the results obtained, the introduction of these novel biomarkers as a tool for the diagnosis of infection in this patient group is not recommended.

The impact of the oral cavity in febrile neutropenia and infectious complications in patients treated with myelosuppressive chemotherapy.

Febrile neutropenia (FN) is an inflammatory response causing fever that may develop during cancer therapy-induced neutropenia. FN may herald life-threatening infectious complications and should therefore be considered a medical emergency. Patients presenting with FN are routinely subjected to careful history taking and physical examination including X-rays and microbiological evaluations. Nevertheless, an infection is documented clinically in only 20-30% of cases, whereas a causative microbial pathogen is not identified in over 70% of FN cases. The oral cavity is generally only visually inspected. Although it is recognized that ulcerative oral mucositis may be involved in the development of FN, the contribution of infections of the periodontium, the dentition, and salivary glands may be underestimated. These infections can be easily overlooked, as symptoms and signs of inflammation may be limited or absent during neutropenia. This narrative review is aimed to inform the clinician on the potential role of the oral cavity as a potential source in the development of FN. Areas for future research directed to advancing optimal management strategies are discussed.

Urine cultures at the onset of febrile neutropenia rarely impact antibiotic management in asymptomatic adult cancer patients.

PURPOSE: There is a paucity of data regarding the utility of routine urine cultures in adults with febrile neutropenia (FN) without urinary symptoms receiving protocolised antibiotics. This is reflected by inconsistent recommendations in international and regional FN guidelines. We addressed this issue by retrospectively reviewing the impact of routine urine cultures on antibiotic management in haematology cancer inpatients at a tertiary hospital. METHODS: All haematology inpatients over a 5-year period (2011-2015) were retrospectively reviewed for episodes of FN (neutrophil count < 0.5 × 109/L and fever > 37.5 °C). For each episode, demographic data, urinary tract symptoms and signs (absence of which was termed 'asymptomatic'), urinalysis and urine culture results, antibiotic therapy and duration, and patient outcomes were collected. A urine culture was considered positive if > 105 colony forming units (CFU)/L were detected. Empiric antibiotic therapy for FN consisted of intravenous piperacillin/tazobactam in stable patients, with the addition of vancomycin and a single dose of gentamicin if systemically compromised. RESULTS: Four hundred and thirty-three episodes of FN were identified in 317 patients. Urine cultures were performed in 362 (84%) episodes. Cultures were positive in 9 of 48 (19%) symptomatic episodes versus 8 of 314 (2.5%) asymptomatic episodes (RR = 7.4, p < 0.0001). A change in antibiotic management due a positive urine culture occurred in only 5 episodes (1.4%): 3 of 48 (6.3%) symptomatic and 2 of 314 (0.6%) asymptomatic episodes respectively (RR = 9.8, p = 0.01). CONCLUSION: Routine urine cultures in FN patients without urinary symptoms who are already receiving protocolised broad spectrum antibiotics rarely impact subsequent antibiotic management.

Evaluation of a Carbapenem-Saving Strategy Using Empirical Combination Regimen of Piperacillin-Tazobactam and Amikacin in Hemato-Oncology Patients.

We implemented a carbapenem-saving strategy in hemato-oncology patients from 2013, using an empirical combination of piperacillin-tazobactam and amikacin for high-risk hemato-oncology patients with febrile neutropenia, who remain hemodynamically unstable > 72 hours despite initial cefepime treatment. All-cause mortality was not different between the two periods (6.54 and 6.57 deaths per 1,000 person-day, P = 0.926). Group 2 carbapenem use significantly decreased after strategy implementation (78.43 vs. 67.43 monthly days of therapy, P = 0.018), while carbapenem-resistant gram-negative bacilli did not show meaningful changes during the study period. Our carbapenem-saving strategy could effectively suppress carbapenem use without an increase of overall mortality.

Antimicrobial stewardship in paediatric oncology: Impact on optimising gentamicin use in febrile neutropenia.

OBJECTIVES: To evaluate the impact of an antimicrobial stewardship (AMS) intervention, involving introduction of new guidelines on the treatment of febrile neutropenia (FN), on improving the use of gentamicin in paediatric oncology patients. DESIGN AND INTERVENTION: Updated guidelines for gentamicin usage in paediatrics with FN were implemented at a tertiary children's teaching hospital, in Brisbane, Australia. Data on gentamicin usage before and after the guideline change were collected retrospectively from children with cancer admitted to hospital with FN between January 2012 and December 2013. Gentamicin use, duration of gentamicin therapy and therapeutic monitoring practice were compared against bacterial culture status for admissions before and after the guideline change to assess the impact on practice. RESULTS: Data were collected from 227 children corresponding to 453 separate admissions, 195 preguideline and 257 post-guideline change. Following guideline change, the proportion of admissions in which gentamicin was administered reduced from 79.0 to 20.9% (P-value < 0.001) and administrations not associated with a cultured Gram-negative organism dropped from 87.2 to 58.2% (P-value < 0.001), indicating a change in practice according to the new guideline. Following guideline change, admissions in which gentamicin was used for >48 hr despite the absence of a confirmed Gram-negative infection decreased from 85.6 to 46.9% (P-value < 0.001). CONCLUSIONS: Guideline changes driven through an AMS initiative involving paediatric oncology patients significantly improved targeted- and nontargeted-antimicrobial use potentially reducing the risk of emergence of resistance against gentamicin in this cohort.

Reduced Neutrophil Elastase Activity and Neutrophil Extracellular Traps in Pediatric Acute Myeloid Leukemia May Increase the Rate of Infections.

Data on the production of neutrophil extracellular traps (NETs) in leukemia patients are scant. Phagocytosis, hydrogen peroxide, neutrophil elastase and myeloperoxidase enzymatic activity as well as NETs formation were studied in 10 pediatric acute lymphoblastic leukemia and 7 pediatric acute myeloid leukemia (AML) patients after induction chemotherapy. Median neutrophil elastase activity and NETs formation were lower in AML versus acute lymphoblastic leukemia (41% vs. 90%, P=0.005 and 51% vs. 94%, P=0.008, respectively). AML patients had more episodes of febrile neutropenia during the first 2 blocks of treatment (100% vs. 40%, P=0.011) and a trend for more invasive bacterial and fungal infections.

Multisite external validation of a risk prediction model for the diagnosis of blood stream infections in febrile pediatric oncology patients without severe neutropenia.

BACKGROUND: Pediatric oncology patients are at an increased risk of invasive bacterial infection due to immunosuppression. The risk of such infection in the absence of severe neutropenia (absolute neutrophil count ≥ 500/µL) is not well established and a validated prediction model for blood stream infection (BSI) risk offers clinical usefulness. METHODS: A 6-site retrospective external validation was conducted using a previously published risk prediction model for BSI in febrile pediatric oncology patients without severe neutropenia: the Esbenshade/Vanderbilt (EsVan) model. A reduced model (EsVan2) excluding 2 less clinically reliable variables also was created using the initial EsVan model derivative cohort, and was validated using all 5 external validation cohorts. One data set was used only in sensitivity analyses due to missing some variables. RESULTS: From the 5 primary data sets, there were a total of 1197 febrile episodes and 76 episodes of bacteremia. The overall C statistic for predicting bacteremia was 0.695, with a calibration slope of 0.50 for the original model and a calibration slope of 1.0 when recalibration was applied to the model. The model performed better in predicting high-risk bacteremia (gram-negative or Staphylococcus aureus infection) versus BSI alone, with a C statistic of 0.801 and a calibration slope of 0.65. The EsVan2 model outperformed the EsVan model across data sets with a C statistic of 0.733 for predicting BSI and a C statistic of 0.841 for high-risk BSI. CONCLUSIONS: The results of this external validation demonstrated that the EsVan and EsVan2 models are able to predict BSI across multiple performance sites and, once validated and implemented prospectively, could assist in decision making in clinical practice. Cancer 2017;123:3781-3790. © 2017 American Cancer Society.

In Vitro Comparison of Ceftolozane-Tazobactam to Traditional Beta-Lactams and Ceftolozane-Tazobactam as an Alternative to Combination Antimicrobial Therapy for Pseudomonas aeruginosa.

Guidelines for the treatment of sepsis, febrile neutropenia, and hospital-acquired pneumonia caused by Pseudomonas aeruginosa include empirical regimens incorporating two antibiotics from different classes with activity against P. aeruginosa for select at-risk patients to increase the likelihood that the organism will be susceptible to at least one agent. The activity against P. aeruginosa and the rates of cross-resistance of ceftolozane-tazobactam were compared to those of the ß-lactam comparators cefepime, ceftazidime, piperacillin-tazobactam, and meropenem alone and cumulatively with ciprofloxacin or tobramycin. Nonurine P. aeruginosa isolates were collected from adult inpatients at 44 geographically diverse U.S. hospitals. MICs were determined using reference broth microdilution methods. Of the 1,257 isolates collected, 29% were from patients in intensive care units and 39% were from respiratory sites. The overall rate of susceptibility to ceftolozane-tazobactam was high at 97%, whereas it was 72 to 76% for cefepime, ceftazidime, piperacillin-tazobactam, and meropenem. The rate of nonsusceptibility to all four comparator ß-lactams was 11%; of the isolates nonsusceptible to the four comparator ß-lactams, 80% remained susceptible to ceftolozane-tazobactam. Among the isolates nonsusceptible to the tested ß-lactam comparators, less than half were susceptible to ciprofloxacin. By comparison, approximately 80% of the ß-lactam-nonsusceptible isolates were susceptible to tobramycin, for overall cumulative susceptibility rates of 94 to 95%, nearly 10% higher than that of the ciprofloxacin-ß-lactam combinations and approaching that of ceftolozane-tazobactam as a single agent. The rates of susceptibility to ceftolozane-tazobactam were consistently high, with little observable cross-resistance. Ceftolozane-tazobactam monotherapy performed at or above the level of commonly utilized combination therapies on the basis of in vitro susceptibilities. Ceftolozane-tazobactam should be considered for use in patients at high risk for resistant P. aeruginosa infection and as an alternative to empirical combination therapy, especially for patients unable to tolerate aminoglycosides.

Assessing the risk of false positive serum galactomannan among patients receiving piperacillin/tazobactam for febrile neutropenia.

Galactomannan (GM) assay is commonly used as an early diagnostic tool for invasive fungal infection (IFI) in high-risk hematology patients. False positivity is frequently observed in GM with the use of piperacillin/tazobactam. The usage of generic drugs over the original brand has a significant cost advantage. The aim of this study was to assess the performance of GM test among patients receiving original and generic piperacillin/tazobactam formulations. The study included 85 adult patients; 62.4% were male with hematological malignancy currently receiving piperacillin/tazobactam. The study group was divided into two groups: patients receiving original and generic piperacillin/tazobactam. Serum GM index was positive in one of 35 patients receiving original piperacillin/tazobactam, whereas it was positive in 46 out of 50 patients receiving generic piperacillin/tazobactam (P < .001). However, the patients receiving generic piperacillin/tazobactam underwent computed tomography (CT) scans more frequently than those receiving original piperacillin/tazobactam (P = .047). In addition, in vitro analysis of GM was performed in two generics and one original piperacillin/tazobactam vials. One generic piperacillin/tazobactam vial included high GM level. False positivity of serum GM with generic formulations of piperacillin/tazobactam is still an ongoing issue in hematology patients. A high rate of serum GM index false positivity may unexpectedly lead to a higher rate of CT scan. Selected piperacillin/tazobactam vials in each batch should be checked for GM to identify a false positivity of GM before purchase.