Piperacillin–tazobactam monotherapy in high-risk febrile and neutropenic cancer patients

Pathogen detection by metagenomic next generation sequencing during neutropenic fever in patients with hematological malignancies

Background

Febrile neutropenia (FN) following chemotherapy is a major cause of morbidity during cancer treatment. The performance of metagenomic next-generation sequencing (mNGS) of circulating cell-free DNA from plasma may be superior to blood culture (BC) diagnostics for identification of causative pathogens. The aim of this study was to validate mNGS (DISQVER test) for the detection of pathogens in hematologic patients with FN.

Methods

We collected paired whole blood specimens from central venous catheter and peripheral vein during FN for BC and mNGS testing. We repeated paired sampling at the earliest after 3 days of fever, which was defined as one FN episode. All clinical data were retrospectively reviewed by an infectious disease expert panel. We calculated percent positive agreement (PPA), percent negative agreement (PNA), percent overall agreement (POA), and sensitivity and specificity.

Results

We analyzed a total of 98 unselected FN episodes in 61 patients who developed predominantly FN after conditioning therapy for allogeneic (n = 22) or autologous (n = 21) hematopoietic stem cell transplantation. Success rate of mNGS was 99% (97/98). Positivity rate of mNGS was 43% (42/97) overall and 32% (31/97) excluding viruses compared to 14% (14/98) in BC. PPA, PNA and POA between mNGS and BC were 84.6% (95% CI, 54.6% to 98.1%), 63.1% (51.9% to 73.4%) and 66% (55.7% to 75.3%), respectively. Sensitivity for bacteria or fungi was 40% (28.0% to 52.9%) and 18.5% (9.9% to 30.0%), respectively.

Conclusion

Pathogen detection by mNGS (DISQVER) during unselected FN episodes shows twofold higher sensitivity and a broader pathogen spectrum than BC.

Efficacy of antibiotic short course for bloodstream infections in acute myeloid leukemia patients with febrile neutropenia: A retrospective comparative study

OBJECTIVES

There is no specific recommendation about antimicrobial treatment length for documented infections in chemotherapy induced febrile neutropenia (FN). Practices have changed along time in our center regarding length of antibiotic treatment. The aim of this study was to compare long versus short antibiotic course for bloodstream infection (BSI) treatment in acute myeloid leukemia (AML) patients during FN.

METHODS

This monocentric retrospective comparative study included all consecutive BSI episodes among AML patients with FN for 3 years (2017-2019). Episodes were classified regarding the length of antibiotic treatment, considered as short course if the treatment lasted ≤ 7 days, except for nonfermenting bacteria and Staphylococcus aureus or lugdunensis for which the threshold was ≤ 10 days and ≤ 14 days, respectively. The primary outcome was the number of BSI relapses in both groups within 30 days of antibiotic discontinuation.

RESULTS

Among 71 AML patients, 104 BSI episodes were included; 48 (46%) received short course treatment. Only 8 (7.6%) BSI episodes relapsed within 30 days of antibiotic discontinuation, 5 having received short course treatment. No association was found between risk of relapse and short course of antibiotic treatment (p = 0.37). The only risk factor significantly associated with BSI relapse was neutropenia duration (p = 0.005).

CONCLUSION

Antibiotic short course seemed as effective as prolonged treatment for BSI in AML patients during FN, with very few relapses at day 30. These encouraging findings should be confirmed through prospective studies.

D-index as a marker of bloodstream infections in patients with allogeneic hematopoietic stem cell transplantation

BACKGROUND

Neutropenia is a risk factor for development of infections; however, the direct effect of neutropenia on development of bloodstream infection (BSI) is not known. D-index, which is area between the neutrophil time curve and a neutrophil count of 0.5 × 10⁹ /L, incorporates the combined effect of severity and duration of neutropenia. We aimed to evaluate whether D-index can be used as a marker for BSI in patients with allogeneic stem cell transplantation.

METHOD

We conducted a retrospective cohort study of patients undergoing allogeneic stem cell transplantation between January 1, 2005, and September 30, 2015. The primary outcome measure was the development of BSI within 30 days of transplantation.

RESULTS

A total of 714 patients were included in the study of whom 101 developed BSI. Patients with BSI had a significantly higher median D-index value compared with patients who did not have BSI (4990 vs. 3570, P < .001). As a marker, the performance of the D-index was similar to that of the duration of profound neutropenia (P = .18) and significantly better than the total duration of neutropenia (P = .001).

CONCLUSION

The D-index performed better than the total duration of neutropenia as a marker for BSI in patients with allogeneic stem cell transplantation. There was no difference between D-index and, a more easily calculable indicator, duration of profound neutropenia.

Piperacillin/tazobactam resistance in a clinical isolate of Escherichia coli due to IS26-mediated amplification of blaTEM-1B

A phenotype of Escherichia coli and Klebsiella pneumoniae, resistant to piperacillin/tazobactam (TZP) but susceptible to carbapenems and 3rd generation cephalosporins, has emerged. The resistance mechanism associated with this phenotype has been identified as hyperproduction of the β-lactamase TEM. However, the mechanism of hyperproduction due to gene amplification is not well understood. Here, we report a mechanism of gene amplification due to a translocatable unit (TU) excising from an IS26-flanked pseudo-compound transposon, PTn6762, which harbours blaTEM-1B. The TU re-inserts into the chromosome adjacent to IS26 and forms a tandem array of TUs, which increases the copy number of blaTEM-1B, leading to TEM-1B hyperproduction and TZP resistance. Despite a significant increase in blaTEM-1B copy number, the TZP-resistant isolate does not incur a fitness cost compared to the TZP-susceptible ancestor. This mechanism of amplification of blaTEM-1B is an important consideration when using genomic data to predict susceptibility to TZP.

Distribution and clinical determinants of time-to-positivity of blood cultures in patients with neutropenia

OBJECTIVES

Blood cultures (BCs) are essential in the evaluation of neutropenic fever. Modern BC systems have significantly reduced the time-to-positivity (TTP) of BC. This study explores the probability of bacteraemia when BCs have remained negative for different periods of time.

METHODS

All adult patients with neutropenia and bacteraemia were included (January 2012-February 2016). Predictive clinical factors for short (≤16 hours) and long (>24 hours) TTP were determined. The residual probability of bacteraemia was estimated for the scenario of negative BC 24 hours after collection.

RESULTS

The cohort consisted of 154 patients, accounting for 190 episodes of bacteraemia. Median age of 61 years, 60.5% were male. In 123 (64.7%) episodes, BC yielded a single Gram-positive micro-organism and in 49 (25.8%) a Gram-negative micro-organism (median TTP 16.7, 14.5 hours respectively, P < .01). TTP was ≤24 hours in 91.6% of episodes. Central line-associated bacteraemia was associated with long TTP. The probability of bacteraemia if BC had remained negative for 24 hours was 1%-3%.

CONCLUSIONS

The expected TTP offers guidance in the management of patients with neutropenia and suspected bacteraemia. The knowledge of negative BC can support a change in working diagnosis, and impact clinical decisions as soon as 24 hours after BC collection.

Prospective study evaluating the incidence of bacteraemia and bacteruria in afebrile and febrile neutropaenic dogs undergoing chemotherapy

The purpose of this prospective study was to determine the incidence and character of bacteraemia and bacteruria in afebrile and febrile neutropaenic dogs undergoing cytotoxic chemotherapy. Fifty‐five neutropaenic dogs presenting to the University of Wisconsin Veterinary Medical Teaching Hospital were enrolled for a total of 57 neutropaenic episodes. The overall incidence of bacteraemia was 12.3% (n = 7/57). Three afebrile dogs and four febrile dogs were bacteraemic; this difference was not significant (P = 0.6968). The overall incidence of bacteruria was 7.5% (n = 4/53). Two afebrile dogs and two febrile dogs were bacteruric; this difference was not significant (P = 1.0). Of the positive blood cultures, the majority of organisms cultured (n = 6/7) were gram‐positive organisms with one gram‐negative organism. Three of the positive blood cultures showed in vitro resistance to more than one antimicrobial agent. Clinical parameters (age, body weight, heart rate, rectal temperature, neutrophil count, haematocrit and platelet count) were not predictive of bacteraemia. The results of this study were not sufficient to justify the use of blood cultures as a first‐line diagnostic test for neutropaenic patients. Blood cultures may have utility in individual case management for a minority of patients in guiding antibiotic choice in the case of resistant bacterial infections. Blood cultures may serve as a tool for antimicrobial de‐escalation, although further study is needed.

Empirical antibiotics targeting gram-positive bacteria for the treatment of febrile neutropenic patients with cancer

BACKGROUND

The pattern of infections among neutropenic patients with cancer has shifted in the last decades to a predominance of gram-positive infections. Some of these gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical anti-gram-positive (antiGP) antibiotic treatment for febrile neutropenic patients with cancer in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH METHODS

For the review update we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2017, Issue 2), MEDLINE (May 2012 to 2017), Embase (May 2012 to 2017), LILACS (2012 to 2017), conference proceedings, ClinicalTrials.gov trial registry, and the references of the included studies. We contacted the first authors of all included and potentially relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing one antibiotic regimen versus the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic patients with cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias, and extracted all data. Risk ratios (RR) with 95% confidence intervals (CIs) were calculated. A random-effects model was used for all comparisons showing substantial heterogeneity (I2 > 50%). Outcomes were extracted by intention-to-treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Fourteen trials and 2782 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in 12 studies, and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Eight studies were assessed in the overall mortality comparison and no significant difference was seen between the comparator arms, RR of 0.90 (95% CI 0.64 to 1.25; 8 studies, 1242 patients; moderate-quality data). Eleven trials assessed failure, including modifications as failures, while seven assessed overall failure disregarding treatment modifications. Failure with modifications was reduced, RR of 0.72 (95% CI 0.65 to 0.79; 11 studies, 2169 patients; very low-quality data), while overall failure was the same, RR of 1.00 (95% CI 0.79 to 1.27; 7 studies, 943 patients; low-quality data). Sensitivity analysis for allocation concealment and incomplete outcome data did not change the results. Failure among patients with gram-positive infections was reduced with antiGP treatment, RR of 0.56 (95% CI 0.38 to 0.84, 5 studies, 175 patients), although, mortality among these patients was not changed.Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates and were associated with a reduction in documented gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Based on very low- or low-quality evidence using the GRADE approach and overall low risk of bias, the current evidence shows that the empirical routine addition of antiGP treatment, namely glycopeptides, does not improve the outcomes of febrile neutropenic patients with cancer.

A clinical evaluation of efficacy and safety of cefepime monotherapy versus piperacillin-tazobactam in patients of paediatric age group with febrile neutropenia in a tertiary care centre of north India

Objective

To evaluate clinically the efficacy and safety in northern India of cefepime monotherapy versus piperacillin-tazobactam in patients of paediatric age group with febrile neutropenia.

Material and Methods

Children aged ≤18 years admitted febrile with chemotherapy-induced neutropenia were randomised into two groups comprising 20 cases in each group viz. CEF (receiving cefepime only) and PIP-TAZO (receiving piperacillin-tazobactam). Based on clinical and laboratory tests, patients were classified into: microbiologically documented infections (MDI); clinically documented infections (CDI); and unexplained fever (UF). They were assessed for clinical signs and symptoms as well as laboratory parameters at the time of enrolment and subsequently on days 3 and 7.

Results

Incidence of MDI, CDI and UF were 22.5%, 47.5% and 30%, respectively. The mean duration of neutropenia (in days) was 5.45 ± 2.1 in the PIP-TAZO group and 5.5 ± 1.5 in the CEF group ( P = 0.305). The success rate defined as clearing infection effectively and improvement of neutropenia was comparable ( P = 0.705). There was a mortality rate of 20% in the PIP-TAZO group as compared to 10% in the CEF group.

Conclusion

We conclude that cefepime monotherapy and piperacillin-tazobactam are equally efficacious and safe in treating patients with febrile neutropenia. Empirical monotherapy with cefepime would prevent an unnecessary extra economic burden as well as avoiding the serious adverse or toxic effects of multi-drug regimes, especially in low- and middle-income countries.

Evaluation of Bloodstream Infections During Chemotherapy-Induced Febrile Neutropenia in Patients with Malignant Hematological Diseases: Single Center Experience

From year to year, it is important to get an overview of the occurrence of causative agents in febrile neutropenic patients to determine the empiric treatment. Thus our aims were to evaluate a four-year period regarding the prevalence of bloodstream infections and the most important causative agents. During this period, 1,361 patients were treated in our hematology ward because of various hematological disorders. 812 febrile episodes were recorded in 469 patients. At that time, 3,714 blood culture (BC) bottles were sent for microbiological investigations, 759 of them gave positive signal. From the majority of positive blood culture bottles (67.1%), Gram-positive bacteria, mainly coagulase-negative staphylococci (CNS), were grown. Gram-negative bacteria were isolated from 32.9% of the positive blood culture bottles, in these cases the leading pathogen was Escherichia coli. The high prevalence of CNS was attributed to mainly contamination, while lower positivity rate for Gram-negative bacteria was associated with the use of broad-spectrum empiric antibiotic treatment.

Secondary Infections in Febrile Neutropenia in Hematological Malignancies: More Than Another Febrile Neutropenic Episode

Objective:

Febrile neutropenic episodes (FNEs) are among the major causes of mortality in patients with hematological malignancies. Secondary infections develop either during the empirical antibiotic therapy or 1 week after cessation of therapy for a FNE. The aim of this study was to investigate the risk factors associated with secondary infections in febrile neutropenic patients.

Materials and Methods:

We retrospectively analyzed 750 FNEs in 473 patients between January 2000 and December 2006.

Results:

Secondary infections were diagnosed in 152 (20%) of 750 FNEs. The median time to develop secondary infection was 10 days (range: 2-34 days). The duration of neutropenia over 10 days significantly increased the risk of secondary infections (p<0.001). The proportion of patients with microbiologically documented infections was found to be higher in primary infections (271/750, 36%) compared to secondary infections (43/152, 28%) (p=0.038). Age; sex; underlying disease; antibacterial, antifungal, or antiviral prophylaxis; blood transfusion or bone marrow transplantation; central venous catheter; and severity of neutropenia did not differ significantly between primary and secondary infections (p>0.05). While fever of unknown origin (p=0.005) and catheter-related bacteremia (p<0.001) were less frequently observed in secondary infections, the frequency of microbiologically (p=0.003) and clinically (p<0.001) documented infections, fungal pneumonias (p<0.001), infections related to gram-positive bacteria (p=0.04) and fungi (p<0.001), and 30-day mortality rate (p<0.001) were significantly higher in cases of secondary infections (p<0.001).

Conclusion:

Secondary infections should be regarded as life-threatening complications of febrile neutropenia. Secondary infections represent a more severe and mortal complication and cannot be regarded just as another FNE.

Meropenem versus piperacillin-tazobactam as empiric therapy for febrile neutropenia in pediatric oncology patients

BACKGROUND

Infection is a serious cause of mortality in febrile neutropenia of pediatric cancer patients. Recently, monotherapy has replaced the combination therapy in empirical treatment of febrile neutropenia. Since there has been no reported trial comparing the efficacy of meropenem and piperacillin-tazobactam (PIP/ TAZ) monotherapies, the present retrospective study was conducted to compare safety and efficacy in febrile neutropenic children with cancer.

MATERIALS AND METHODS

Charts of febrile, neutropenic children hospitalized at our center between March 2008 and April 2011 for hemato-oncological malignancies were reviewed. Patients received PIP/TAZ 360 mg/kg/day or meropenem 60 mg/kg/day intravenously in three divided doses. Duration of fever and neutropenia, absolute neutrophil count, modification, and success rate were compared between the two groups. Resolution of fever without antibiotic change was defined as success and resolution of fever with antibiotic change or death of a patient was defined as failure. Modification was defined as changing the empirical antimicrobial agent during a febrile episode.

RESULTS

Two hundred eighty four febrile neutropenic episodes were documented in 136 patients with a median age of 5 years. In 198 episodes meropenem and in 86 episodes PIP/ TAZ were used. Duration of fever and neutropenia, neutrophil count, sex, and primary disease were not different between two groups. Success rates and modification rate between two groups showed no significant differences (p>0.05). Overall success rate in the meropenem and PIP/TAZ groups were 92.4% and 91.9% respectively. No serious adverse effects occurred in either of the groups.

CONCLUSIONS

Meropenem and PIP/TAZ monotherapy are equally safe and effective in the initial treatment of febrile neutropenia in children with cancer.

Bacterial bloodstream infections and antimicrobial susceptibility pattern in pediatric hematology/oncology patients after anticancer chemotherapy

Purpose

Bloodstream infections in pediatric hematology and oncology represent a major problem worldwide, but this has not been studied in Qatar. In this study, we investigated the burden of infection and the resistance pattern in the bacterial etiology, in the only tertiary pediatric hematology and oncology center in Qatar.

Methods

All pediatric cancer patients (n=185) were evaluated retrospectively during the period 2004–2011; a total of 70 (38%) patients were diagnosed with bloodstream infections. Bacterial etiology was determined, along with their susceptibility patterns. Neutropenia, duration of neutropenia, fever, duration of fever, and C-reactive protein (CRP) were evaluated throughout the study.

Results

A total of 70 patients (38%) were diagnosed with acute leukemias, lymphomas, solid tumors, or brain tumors; those patients experienced 111 episodes of bacteremia. The most common Gram-positive (n=64 [55%]) isolates were Staphylococcus epidermidis (n=26), Staphylococcus hominis (n=9), and Staphylococcus haemolyticus (n=7), and the common Gram-negative (n=52 [45%]) isolates were Klebsiella pneumoniae (n=14), Pseudomonas aeruginosa (n=10), and Escherichia coli (n=7). There was a significant association observed between fever with positive blood culture and different types of cancer (P=0.035). The majority of bacteremia (n=68 [61.3%]) occurred in nonneutropenic episodes. Elevated values of CRP (≥5 mg/L) were detected in 82 (95.3%) episodes and were negatively correlated with absolute neutrophil count (ANC) (r=−0.18; P=0.248) among all cases. However, the infection-related fatality rate was 2.2% (n=4), with three caused by Gram-negative pathogens. Multidrug resistant organisms were implicated in 33 (28.4%) cases and caused three of the mortality cases.

Conclusion

Multidrug resistant organisms cause mortality in pediatric cancer patients. Investigation of antimicrobial susceptibility of these organisms may guide successful antimicrobial therapy and improve the surveillance and quality of pediatric malignancy care.

European guidelines for empirical antibacterial therapy for febrile neutropenic patients in the era of growing resistance: summary of the 2011 4th European Conference on Infections in Leukemia

Owing to increasing resistance and the limited arsenal of new antibiotics, especially against Gram-negative pathogens, carefully designed antibiotic regimens are obligatory for febrile neutropenic patients, along with effective infection control. The Expert Group of the 4(th) European Conference on Infections in Leukemia has developed guidelines for initial empirical therapy in febrile neutropenic patients, based on: i) the local resistance epidemiology; and ii) the patient's risk factors for resistant bacteria and for a complicated clinical course. An 'escalation' approach, avoiding empirical carbapenems and combinations, should be employed in patients without particular risk factors. A 'de-escalation' approach, with initial broad-spectrum antibiotics or combinations, should be used only in those patients with: i) known prior colonization or infection with resistant pathogens; or ii) complicated presentation; or iii) in centers where resistant pathogens are prevalent at the onset of febrile neutropenia. In the latter case, infection control and antibiotic stewardship also need urgent review. Modification of the initial regimen at 72-96 h should be based on the patient's clinical course and the microbiological results. Discontinuation of antibiotics after 72 h or later should be considered in neutropenic patients with fever of unknown origin who are hemodynamically stable since presentation and afebrile for at least 48 h, irrespective of neutrophil count and expected duration of neutropenia. This strategy aims to minimize the collateral damage associated with antibiotic overuse, and the further selection of resistance.

Structure-based repurposing of FDA-approved drugs as inhibitors of NEDD8-activating enzyme

We report the discovery of an inhibitor of NEDD8-activating enzyme (NAE) by an integrated virtual screening approach. Piperacillin 1 inhibited NAE activity in cell-free and cell-based systems with high selectivity. Furthermore, piperacillin 1 was able to inhibit the degradation of the NAE downstream protein substrate p27(kip1). Our molecular modeling and kinetic studies suggested that this compound may act as a non-covalent ATP-competitive inhibitor of NAE.

Empirical antibiotics targeting Gram-positive bacteria for the treatment of febrile neutropenic patients with cancer

BACKGROUND

The pattern of infections among neutropenic cancer patients has shifted in the last decades to a predominance of Gram-positive infections. Some of these Gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical antiGram-positive (antiGP) antibiotic treatment for febrile neutropenic cancer patients in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 7), MEDLINE (1966 to 2013), EMBASE (1982 to 2013), LILACS (1982 to 2013), conference proceedings, and the references of the included studies. First authors of all included and potentially relevant trials were contacted.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing one antibiotic regimen to the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic cancer patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial eligibility and risk of bias, and extracted all data. Risk ratios (RR) with 95% confidence intervals (CI) were calculated. A random-effects model was used for all comparisons showing substantial heterogeneity (I(2) > 50%). Outcomes were extracted by intention to treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Thirteen trials and 2392 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in 11 studies, and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Seven studies were assessed in the overall mortality comparison and no significant difference was seen between the comparator arms, RR of 0.82 (95% CI 0.56 to 1.20, 852 patients). Ten trials assessed failure, including modifications as failures, while six assessed overall failure disregarding treatment modifications. Failure with modifications was significantly reduced, RR of 0.76 (95% CI 0.68 to 0.85, 1779 patients) while overall failure was the same, RR of 1.00 (95% CI 0.79 to 1.27, 943 patients). Sensitivity analysis for allocation concealment and incomplete outcome data did not change the results. Both mortality and failure did not differ significantly among patients with Gram-positive infections, but the number of studies in the comparisons was small. Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates and were associated with a reduction in documented Gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Current evidence shows that the empirical routine addition of antiGP treatment, namely glycopeptides, does not improve the outcomes of febrile neutropenic patients with cancer.

Targeted therapy against multi-resistant bacteria in leukemic and hematopoietic stem cell transplant recipients: guidelines of the 4th European Conference on Infections in Leukemia (ECIL-4, 2011)

The detection of multi-resistant bacterial pathogens, particularly those to carbapenemases, in leukemic and stem cell transplant patients forces the use of old or non-conventional agents as the only remaining treatment options. These include colistin/polymyxin B, tigecycline, fosfomycin and various anti-gram-positive agents. Data on the use of these agents in leukemic patients are scanty, with only linezolid subjected to formal trials. The Expert Group of the 4(th) European Conference on Infections in Leukemia has developed guidelines for their use in these patient populations. Targeted therapy should be based on (i) in vitro susceptibility data, (ii) knowledge of the best treatment option against the particular species or phenotype of bacteria, (iii) pharmacokinetic/pharmacodynamic data, and (iv) careful assessment of the risk-benefit balance. For infections due to resistant Gram-negative bacteria, these agents should be preferably used in combination with other agents that remain active in vitro, because of suboptimal efficacy (e.g., tigecycline) and the risk of emergent resistance (e.g., fosfomycin). The paucity of new antibacterial drugs in the near future should lead us to limit the use of these drugs to situations where no alternative exists.

Bacteremia in Swedish hematological patients with febrile neutropenia: bacterial spectrum and antimicrobial resistance patterns

BACKGROUND

The etiology of bacteremia in hematological patients with febrile neutropenia differs geographically and changes over time. Since efficient empirical antibiotic treatment depends on relevant knowledge of the bacterial panorama, the aim of this study was to describe the prevalence of bacteremia, the bacterial spectrum, and the resistance patterns of the isolates in this group today.

METHODS

In a cross-sectional study, routine blood cultures from febrile episodes occurring in adult patients with hematological disorders and neutropenia presenting to Karolinska University Hospital, Stockholm, Sweden during a 24-month period, were analyzed.

RESULTS

A total of 142 febrile neutropenic episodes occurring in 124 hematological patients were included in the study. Bacteremia was documented in 27% of the episodes, and of these, 58% were due to Gram-positive pathogens. The most common isolates were viridans streptococci, coagulase-negative staphylococci, and Escherichia coli. Low levels of antibiotic resistance were detected. The underlying diagnosis of non-Hodgkin's lymphoma (NHL) was independently negatively associated with documented bacteremia (p < 0.01).

CONCLUSIONS

The prevalence of bacteremia and the bacterial spectrum were consistent with recent Scandinavian reports. Substantially lower levels of antimicrobial resistance were registered compared to those found in other European centers. Patients with NHL were less likely to have documented bacteremia in this study.

Viral findings in adult hematological patients with neutropenia

Background

Until recently, viral infections in patients with hematological malignancies were concerns primarily in allogeneic hematopoietic stem cell transplant (HSCT) recipients. During the last years, changed treatment regimens for non-transplanted patients with hematological malignancies have had potential to increase the incidence of viral infections in this group. In this study, we have prospectively investigated the prevalence of a broad range of respiratory viruses in nasopharyngeal aspirate (NPA) as well as viruses that commonly reactivate after allogeneic HSCT.

Methodology/Principal Findings

Patients with hematological malignancies and therapy induced neutropenia (n = 159) were screened regarding a broad range of common respiratory viruses in the nasopharynx and for viruses commonly detected in severely immunosuppressed patients in peripheral blood. Quantitative PCR was used for detection of viruses. A viral pathogen was detected in 35% of the patients. The detection rate was rather similar in blood (22%) and NPA (18%) with polyoma BK virus and rhinovirus as dominating pathogens in blood and NPA, respectively. Patients with chronic lymphocytic leukemia (CLL) (p<0.01) and patients with fever (p<0.001) were overrepresented in the virus-positive group. Furthermore, viral findings in NPA were associated with upper respiratory symptoms (URTS) (p<0.0001).

Conclusions/Significance

Both respiratory viral infections and low titers of viruses in blood from patients with neutropenia were common. Patients with CLL and patients with fever were independently associated to these infections, and viral findings in NPA were associated to URTS indicating active infection. These findings motivate further studies on viruses' impact on this patient category and their potential role as causative agents of fever during neutropenia.

Piperacillin/tazobactam versus cefozopran for the empirical treatment of pediatric cancer patients with febrile neutropenia

BACKGROUND

The aim of this study was to evaluate the efficacy and safety of piperacillin/tazobactam (PIP/TAZO) and cefozopran (CZOP) monotherapy in pediatric cancer patients with febrile neutropenia (FN).

PROCEDURE

A total of 119 febrile episodes in 49 neutropenic pediatric cancer patients (20 females and 29 males) with a median age of 6.8 years (range, 0.3-18.4 years) received randomized treatment either with PIP/TAZO 125 mg/kg every 8 hr or CZOP 25 mg/kg every 6 hr. Clinical response was determined at completion of therapy. Durations of fever and neutropenia, the need for modification of the therapy, and mortality rates were compared between the two groups.

RESULTS

The frequency of success without modification of treatment was not significantly different between PIP/TAZO (59.6%) and CZOP (53.2%). Durations of fever and antibiotic therapy did not differ between the treatment groups, and no major side effects were observed in either group.

CONCLUSIONS

PIP/TAZO and CZOP monotherapy were both effective and safe for the initial empirical treatment of pediatric cancer patients with FN.

The use of antimicrobial agents in children with fever during chemotherapy-induced neutropenia: the importance of risk stratification

Children with fever and chemotherapy-induced or cancer-associated neutropenia should be assessed with complete history and physical examinations, undergo appropriate diagnostic studies, and promptly receive broad-spectrum empirical antimicrobial therapy. Assessment of risk for severe infection is crucial in determining the appropriate antimicrobial, route, venue, and duration of empirical antimicrobial therapy and need for prophylactic antimicrobial agents.

Immunohematopoietic stem cell transplantation in Cape Town: a ten-year outcome analysis in adults

BACKGROUND AND OBJECTIVES

Immunohematopoietic stem cell transplantation has curative potential in selected hematologic disorders. Stem cell transplantation was introduced into South Africa in 1970 as a structured experimental and clinical program. In this report, we summarize the demography and outcome by disease category, gender, and type of procedure in patients older than 18 years of age who were seen from April 1995 to December 2002.

PATIENTS AND METHODS

This retrospective analysis included 247 individuals over 18 years of age for whom complete data were available. These patients received grafts mostly from peripheral blood with the appropriate stem cell population recovered by apheresis.

RESULTS

Patient ages ranged from 20 to 65 years with a median age of 42 years. There were 101 females and 146 males. There were no withdrawals and 63% survived to the end of the study. At 96 months of follow-up, a stable plateau was reached for each disease category. Median survival was 3.3 years (n=6, 14.6%) for acute lymphoblastic anemia, 3.1 years (n=44, 18%) for acute myeloid leukemia, 2.8 years (n=47, 19%) for chronic granulocytic leukemia, 2.8 years (n=71, 29%) for lymphoma, 1.5 years (n=23, 9%) for myeloma, 1.43 years (n=10, 4%) for aplasia, and 1.4 years (n=38, 15%) for a miscellaneous group comprising less than 10 examples each. Multivariate analysis showed that only diagnosis and age had a significant impact on survival, but these two variables might be interrelated. There was no significant difference in outcome by source of graft.

CONCLUSION

The results confirm that procedures carried out in a properly constituted and dedicated unit, which meets established criteria and strictly observes treatment protocols, generate results comparable to those in a First World referral center. Low rates of transplant-related mortality, rejection and graft-versus-host disease are confirmed, but the benefits cannot be extrapolated outside of academically oriented and supervised facilities.

Multiplex blood PCR in combination with blood cultures for improvement of microbiological documentation of infection in febrile neutropenia

The frequent lack of microbiological documentation of infection by blood cultures (BC) has a major impact on clinical management of febrile neutropenic patients, especially in cases of unexplained persistent fever. We assessed the diagnostic utility of the LightCycler SeptiFast test (SF), a multiplex blood PCR, in febrile neutropenia. Blood for BC and SF was drawn at the onset of fever and every 3 days of persistent fever. SF results were compared with those of BC, clinical documentation of infection, and standard clinical, radiological, and microbiological criteria for invasive fungal infections (IFI). A total of 141 febrile neutropenic episodes in 86 hematological patients were studied: 44 (31%) microbiologically and 49 (35%) clinically documented infections and 48 (34%) unexplained fevers. At the onset of fever, BC detected 44 microorganisms in 35/141 (25%) episodes. Together, BC and SF identified 78 microorganisms in 61/141 (43%) episodes (P = 0.002 versus BC or SF alone): 12 were detected by BC and SF, 32 by BC only, and 34 by SF only. In 19/52 (37%) episodes of persistent fever, SF detected 28 new microorganisms (7 Gram-positive bacterial species, 15 Gram-negative bacterial species, and 6 fungal species [89% with a clinically documented site of infection]) whereas BC detected only 4 pathogens (8%) (P = 0.001). While BC did not detect fungi, SF identified 5 Candida spp. and 1 Aspergillus sp. in 5/7 probable or possible cases of IFI. Using SeptiFast PCR combined with blood cultures improves microbiological documentation in febrile neutropenia, especially when fever persists and invasive fungal infection is suspected. Technical adjustments may enhance the efficiency of this new molecular tool in this specific setting.

Imipenem-cilastatin versus piperacillin-tazobactam as monotherapy in febrile neutropenia

BACKGROUND

In view of the recent trend toward monotherapy in the treatment of febrile neutropenia, we evaluated the clinical efficacy and safety of imipenem-cilastatin versus piperacillin-tazobactam as an empiric therapy for febrile neutropenia in children with malignant diseases.

METHODS

Febrile neutropenic patients received either imipenem-cilastatin or piperacillin-tazobactam randomly. Improvement without any changes in the initial antibiotic treatment was defined as "success" and improvement with modification of the initial treatment and death was defined as "failure".

RESULTS

Over 12 months, 99 febrile neutropenic episodes were treated with monotherapy in 63 patients with a median age of 5 years. At admission, median absolute neutrophil count was 50/mm(3) and in 67% of episodes, neutrophil count was under 100/mm(3). Median duration of neutropenia was 5 days. In 22% of episodes, neutropenia persisted for more than 10 days. Piperacillin-tazobactam was used in 52 episodes and imipenem-cilastatin was used in 47 episodes. There was no difference between groups in terms of age, sex, primary diseases, neutrophil count or duration of neutropenia. In the whole group, the success rate was 67% and the failure rate was 33%, whereas in the piperacillin-tazobactam group, the rates were 71% and 29%; and in the imipenem-cilastatin group they were 62% and 38%, respectively (P > 0.05). There were no deaths. No major adverse effects were seen in either group.

CONCLUSIONS

Although failure was slightly higher in the imipenem-cilastatin group, this was statistically insignificant. Both of these antibiotics can be used safely for initial empirical monotherapy of febrile neutropenia.

Piperacillin/tazobactam versus cefepime for the empirical treatment of pediatric cancer patients with neutropenia and fever: a randomized and open-label study

OBJECTIVES

This is a prospective, randomized, and open-label clinical trial that examines the efficiency and safety of PIP/TAZO monotherapy in comparison to cefepime (CEF), for the empirical treatment of pediatric cancer patients with neutropenia and fever.

METHODS

One hundred thirty-one consecutive febrile episodes in 70 neutropenic pediatric cancer patients received randomized treatment either with piperacillin/tazobactam (PIP/TAZO) 80 mg/kg piperacillin/10 mg/kg tazobactam every 6 hr or CEF 50 mg/kg every 8 hr. Clinical response was determined at completion of therapy. Duration of fever, neutropenia, hospitalization, the need for modification of the therapy, and mortality rates were compared between the two groups.

RESULTS

One hundred twenty-seven episodes in 69 patients (35 females, 34 males) with a median age of 4.2 years were assessed for efficiency (65 PIP/TAZO, 62 CEF). The frequency of success without modification of treatment was nearly identical for both PIP/TAZO (60.0%) and CEF (61.3%) (P > 0.05). The overall response rate, with or without modification of assigned treatment, was 96.9% for PIP/TAZO and 98.4% for CEP (P > 0.05). Infection-related mortality at the end of the febrile episode was 2.4%. Duration of fever and hospitalization were not different between the treatment groups. No major side effects were observed in neither of the groups.

CONCLUSIONS

PIP/TAZO treatment was as effective and safe as CEF monotherapy as an initial empirical regimen in pediatric cancer patients with fever and neutropenia.

Comparison of infectious complications during induction/consolidation chemotherapy versus allogeneic hematopoietic stem cell transplantation

Induction/consolidation chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT) for hematological malignancies are associated with treatment-related risks such as infections. The predominant types of infections are blood stream infections (BSIs) and respiratory tract infections. We prospectively compared infectious complications after induction/consolidation chemotherapy versus allogeneic HSCT in a directly comparable setting with both groups being hospitalized on the same ward. From July 2003 until June 2008, 492 hospitalizations of 321 patients took place; 237 chemotherapies and 255 HSCTs were performed. We observed 49 (20.7%) BSIs, 70 (29.5%) pneumonias and 11 (4.6%) probable or proven invasive mould infections in the chemotherapy group. In the HSCT group we detected 70 (27.5%) BSIs, 71 (27.8%) pneumonias and 14 (5.4%) probable or proven invasive mould infections. There was a trend toward more transfers to the intensive care unit (OR 1.61; 95%CI 0.95-2.72; P=0.074) and BSIs (OR 1.45; 95%CI 0.95-2.22; P=0.079) after HSCT; 44 (13.7%) patients died. In-hospital mortality was significantly higher in the HSCT group (OR 2.39; 95%CI 1.22-4.68; P=0.010). We conclude that the risk of pneumonia and invasive mould infection is comparable after induction/consolidation chemotherapy and allogeneic HSCT. However, there was a trend for more BSIs and intensive care unit stays and a higher mortality in the latter.

Reassessment of recommended imipenem doses in febrile neutropenic patients with hematological malignancies

Imipenem plasma concentrations were analyzed in 57 febrile neutropenic patients using the NONMEM program. The recommended 2-g/day regimen achieved coverage of the most common bacteria (MIC(90) = 1 mg/liter) during the whole dosing interval in only 53% of patients. This goal was achieved in 90% of patients with 3 g/day.

A prospective, randomized study comparing cefozopran with piperacillin-tazobactam plus ceftazidime as empirical therapy for febrile neutropenia in children with hematological disorders

BACKGROUND

The aim of this randomized study was to evaluate the efficacy of cefozopran monotherapy and piperacillin-tazobactam plus ceftazidime (PIPC/TAZ + CAZ) combination therapy in pediatric neutropenic patients.

PROCEDURE

A total of 51 patients with 138 episodes of febrile neutropenia received antibiotic therapy. Of these episodes, 95 were considered eligible for the study. The episodes were treated randomly with either piperacillin-tazobactam (125 mg/kg/day) plus ceftazidime (100 mg/kg/day) or with cefozopran (100 mg/kg/day). Success was defined as resolution of fever and clinical signs of infection within 120 hr following initiation of antibiotic therapy. Duration of neutropenia did not differ statistically between the two groups, and resolution of fever in all cases without complication was seen before recovery from severe neutropenia.

RESULTS

The overall success rate was 61%. There was no statistically significant difference between the two groups: 53% for PIPC/TAZ + CAZ versus 69% for cefozopran (P = 0.122). Blood cultures were positive in eight episodes (8.4%), but there were not deaths as a result of infection.

CONCLUSION

Both cefozopran and PIPC/TAZ + CAZ combination therapy are safe and well tolerated in pediatric neutropenic patients. Our results show that cefozopran is a good candidate for monotherapy for neutropenic fever.

Piperacillin/tazobactam plus amikacin versus carbapenem monotherapy as empirical treatment of febrile neutropenia in childhood hematological malignancies

A prospective, randomized clinical trial was conducted to compare the efficacy of piperacillin/tazobactam and amikacin combination with carbapenem monotherapy for the empirical treatment of febrile neutropenic episodes of children with acute lymphoblastic leukemia or acute myeloblastic leukemia. Patients aged 2-16 years with hematological malignancies who had febrile neutropenia were randomly assigned to receive piperacillin/tazobactam (80 mg/kg piperacillin/10 mg/kg tazobactam, q6h) combined with amikacin (PTA) (7.5 mg/kg, q12h) or meropenem or imipenem (20 mg/kg, q8h) (C). Response to antimicrobial therapy, evaluated for etiological agents, was measured. Duration of fever, neutropenia, and hospitalization, mortality, and the need for additional antibiotics or antifungal drugs were compared for the treatment success between the two groups. Out of 87 febrile neutropenic episodes that were evaluable for comparison, 46 patients received PTA and 41 patients were treated with carbapenems (imipenem or meropenem). Overall, the microbiologically documented infection rate was 21.9%, with Staphylococcus epidermidis as the most common cause of bacteremia. The rate of treatment modification was 56.5% in the PTA group and 53.6% in the carbapenem group with no statistical difference (p > .05). There was no infection-related mortality during the study period. There was no difference between the two regimens for durations of fever, neutropenia, and hospitalization (p > .05 for all categories). PTA was as effective as carbapenem monotherapy as an initial empirical regimen in febrile neutropenic episodes of pediatric hematological malignancies.

Antibacterial prophylaxis in neutropenic patients

Antibiotic prophylaxis has been used for several decades to prevent infection in chemotherapy-induced neutropenia and its benefits have been debated just as long. Recent analysis suggests that quinolones may actually be life saving in high-risk groups such as acute leukaemia and autologous bone marrow transplant but these benefits are likely to be negated in the long term by the development of quinolone resistance.

Bacteraemia in febrile neutropenic cancer patients

A total of 2142 patients with febrile neutropenia resulting from cancer chemotherapy were registered in two observational studies and followed prospectively in different institutions. There were 499 (23%) patients with bacteraemia who are reviewed here. The relative frequencies of Gram-positive, Gram-negative and polymicrobial bacteraemias were 57%, 34% and 10% with respective mortality rates of 5%, 18% and 13%. Mortality rates were significantly higher in bacteraemic patients than in non-bacteraemic patients; a trend for higher mortality was observed (without reaching statistical significance) in those patients in whom bacteraemia was associated with a clinical site of infection compared to bacteraemic patients without any clinical documentation. Prophylactic antibiotics but not granulopoiesis stimulating factors were associated with a lower incidence of Gram-negative bacteraemia; however, neither prophylactic approach influenced the subsequent rate of complications in the patients who developed bacteraemia. The present study also confirms that the MASCC scoring system can identify a group of bacteraemic patients with a relatively low risk of complications and death (MASCC >/=21). On the other hand, in patients with very low levels of the MASCC score (<15), and then with predicted very unfavourable risk, the rate of complications and death was dramatically high, irrespective of the microbiological nature of the bacteraemia.

Piperacillin-tazobactam: a beta-lactam/beta-lactamase inhibitor combination

Piperacillin-tazobactam is a beta-lactam/beta-lactamase inhibitor combination with a broad spectrum of antibacterial activity that includes Gram-positive and -negative aerobic and anaerobic bacteria. Piperacillin-tazobactam retains its in vitro activity against broad-spectrum beta-lactamase-producing and some extended-spectrum beta-lactamase-producing Enterobacteriaceae, but not against isolates of Gram-negative bacilli harboring AmpC beta-lactamases. Piperacillin-tazobactam has recently been reformulated to include ethylenediaminetetraacetic acid and sodium citrate; this new formulation has been shown to be compatible in vitro with the two aminoglycosides, gentamicin and amikacin, allowing for simultaneous Y-site infusion, but not with tobramycin. Multicenter, randomized, double-blinded clinical trials have demonstrated piperacillin-tazobactam to be as clinically effective as relevant comparator antibiotics. Clinical trials have demonstrated piperacillin-tazobactam to be effective for the treatment of patients with intra-abdominal infections, skin and soft tissue infections, lower respiratory tract infections, complicated urinary tract infections, gynecological infections and more recently, febrile neutropenia. Piperacillin-tazobactam has an excellent safety and tolerability profile and continues to be a reliable option for the empiric treatment of moderate-to-severe infections in hospitalized patients.

Empirical antimicrobial treatment for chemotherapy-induced febrile neutropenia

Febrile neutropenia in immunocompromised hosts is associated with a high mortality. Empirical treatment in such cases is instituted to cover the common pathogens. Generally, combination antibiotic treatment is used early in the febrile neutropenia phase. Recent studies demonstrate that monotherapy with certain beta-lactam antibiotics can be equally effective. Glycopeptide antibiotics are used in the absence of an adequate response to the initial antibiotics. Empirical antifungal therapy may be given if fever does not settle in 72-96 h despite antibiotics. Newer antifungal agents have increased the available options for initial antifungal agents though more data are needed before any conclusive recommendation can be made. Recent changes in the epidemiology of multiresistant organisms necessitate local microbiological input into empiric policies with increasing need to consider cover for methicillin-resistant Staphylococcus aureus, glycopeptide intermediate S. aureus, vancomycin-resistant S. aureus, vancomycin-resistant enterococci, Gram-negative bacilli that produce extended-spectrum beta-lactamases, Stenotrophomonas maltophilia, and multi-resistant Acinetobacter baumanii.

Additional anti-Gram-positive antibiotic treatment for febrile neutropenic cancer patients

BACKGROUND

The pattern of infections among neutropenic cancer patients has shifted in the last decades to a predominance of Gram-positive infections. Some of these Gram-positive bacteria are increasingly resistant to beta-lactams and necessitate specific antibiotic treatment.

OBJECTIVES

To assess the effectiveness of empirical anti-Gram-positive (antiGP) antibiotic treatment for febrile neutropenic cancer patients in terms of mortality and treatment failure. To assess the rate of resistance development, further infections and adverse events associated with additional antiGP treatment.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004), MEDLINE (1966 to 2004), EMBASE (January 1980 to 2004), LILACS (1982 to 2004), conference proceedings, and all references of included studies. First authors of all included and potentially relevant trials were contacted.

SELECTION CRITERIA

Randomised controlled trials comparing one antibiotic regimen to the same regimen with the addition of an antiGP antibiotic for the treatment of febrile neutropenic cancer patients.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and extracted all data. Relative risks (RR) with 95% confidence intervals (CI) were calculated. A random effects model was used for all comparisons showing substantial heterogeneity (I(2 )> 50%). Outcomes were extracted by intention-to-treat and the analysis was patient-based whenever possible.

MAIN RESULTS

Thirteen trials and 2392 patients or episodes were included. Empirical antiGP antibiotics were tested at the onset of treatment in eleven studies and for persistent fever in two studies. The antiGP treatment was a glycopeptide in nine trials. Seven studies were assessed in the overall mortality comparison and no significant difference between the comparator arms was seen, RR 0.82 (95% CI 0.56 to 1.20, 852 patients). Ten trials assessed failure including modifications as failures, while six assessed overall failure, disregarding treatment modifications. Failure with modifications was significantly reduced, RR 0.76 (95% CI 0.68 to 0.85, 1779 patients) while overall failure was equal, RR 1.00, 95% CI (0.79 to 1.27, 943 patients). Both mortality and failure did not differ significantly among patients with Gram-positive infections, but comparisons were small. Data regarding other patient subgroups likely to benefit from antiGP treatment were not available. Glycopeptides did not increase fungal superinfection rates, and were associated with a reduction in documented Gram-positive superinfections. Resistant colonisation was not documented in the studies.

AUTHORS' CONCLUSIONS

Current evidence shows that the addition of antiGP treatment, namely glycopeptides, prior to documentation of a Gram-positive infection does not improve outcomes.