Microbiological findings in febrile neutropenia

The role of colonization with resistant Gram negative bacteria in the treatment of febrile neutropenia after stem cell transplantation

INTRODUCTION

Febrile neutropenia (FN) is one of the most common complications of stem cell transplantation. The aim of this analysis was to evaluate the frequency of sepsis in patients with FN colonized with resistant Gram negative bacteria (Extended spectrum β-lactamase positive, multidrug resistant (MDR) P. aeruginosa) and the choice of primary antibiotic in colonized patients.

PATIENTS AND METHODS

This was a retrospective study analyzed data from patients who underwent hematopoietic stem cell transplantation from 01/2018 to 09/2022. Data were extracted from the hospital information system.

RESULTS

Carbapenem as the primary antibiotic of choice was chosen in 10.9% of non-colonized +/-AmpC patients, 31.5% of ESBL+ patients, and 0% of MDR P. aeruginosa patients. Patients with FN and MDR P. aeruginosa colonization had a high prevalence of sepsis (namely 100%, p = 0.0197). The spectrum of sepsis appeared to be different, with Gram negative bacilli predominating in the ESBL+ group (p = 0.0123, OR 5.39 [95% CI 1.55-18.76]). Colonizer sepsis was present in 100% of sepsis with MDR P. aeruginosa colonization (p=0.002), all in allogeneic transplantation (p=0.0003), with a mortality rate of 33.3% (p=0.0384). The incidence of sepsis in patients with ESBL+ colonization was 25.9% (p=0.0197), with colonizer sepsis in 50% of sepsis cases (p=0.0002), most in allogeneic transplantation (p=0.0003).

CONCLUSION

The results show a significant risk of sepsis in FN with MDR P. aeruginosa colonization, this state is almost exclusively caused by the colonizer. At the same time, a higher risk of Gram negative sepsis has been demonstrated in patients colonized with ESBL+ bacteria.

Clinical and Microbiological Characteristics of Febrile Neutropenia During Induction Chemotherapy in Adults With Acute Leukemia

BACKGROUND

Few studies regarding infectious causes of febrile neutropenia (FN) in Mexico are available.

AIMS

We aimed to describe clinical and microbiological characteristics of FN episodes during induction chemotherapy in adults with acute leukemia.

METHODS AND RESULTS

This retrospective cohort from a Mexican tertiary care center included adults with newly diagnosed acute leukemia between January 2014, and December 2018. Clinical and microbiological characteristics were summarized using descriptive statistics. Univariate analyses for associations between clinical characteristics and FN and/or death were made; logistic regression analysis was performed to assess relationships with FN. Kaplan-Meier survival estimates were modeled for antimicrobial prophylaxis and FN. Ninety-five patients were included. Median age was 28 (IQR 20-43), 49 (52%) were males, and 74 (78%) developed FN (74/95). Among these, 98% had an identified source of infection (73/74) and 65% had >1. Common infections were urinary tract infection (24%), bacterial sinusitis (20%), and bacterial pneumonia (19%). Gram-negatives were the most frequently isolated microorganisms (69%), followed by Gram-positives (21%), and fungi (9%). Antimicrobial prophylaxis was inversely associated with FN (aOR = 0.07, CI 0.008-0.060, p = 0.02). Invasive fungal diseases were associated with 30-day mortality (aOR = 9.46, 95% CI 1.66-54.05).

CONCLUSION

Infections caused 98% of the FN episodes. Gram-negative bacteria are the most common pathogens.

Microbiological Spectrum of Neutropenic Sepsis in Cancer Patients Admitted to a Tertiary Health Care Centre

OBJECTIVE

To examine the microbiological profile, sensitivity of organisms, treatment and outcomes of in-patients suffering from febrile neutropenia in a tertiary healthcare centre.

METHODS

Data was obtained from the Electronic Medical Health records in Aster Medcity, Cochin, IND. The study population included adult patients undergoing treatment for hematologic malignancies or solid tumors in the hospital between January 2021 and March 2023. Febrile neutropenia episodes were identified based on (1) absolute neutrophil count ≤1500 mm3, (2) at least a single recorded oral temperature of >38.0∘C (100.4∘F) sustained over a one-hour period. Febrile neutropenia consequences included ICU admission, length of ICU admission, and mortality.

RESULTS

Total 115 cases of febrile neutropenia were identified in the time period from January 2021 to March 2023. Organisms were isolated from 43% of all the cultures taken. The most common organism isolated was Klebsiella pneumoniae (32.81%), followed by Escherichia coli (29.69%) and Pseudomonas aeruginosa (10.94%). Other organisms that were also isolated were Candida albicans (3.13%), Aeromonas hydrophilia, Acinetobacter baumannii, Burkholderia cepacia, Enterobacter cloacae, Enterococcus faecium, Staphylococcus epidermidis, Staphylococcus hemolyticus, Streptococcus spp, and one case of Ralstonia mannitolytica. Multi-drug resistance (MDR) was seen in 33% of isolates and extensive-drug resistance was seen in 19% of isolates. E. coli showed the highest prevalence of antibiotic resistance with 68% growing MDR isolates and 16% growing XDR isolates. ICU stay was required in 34% of patients with a median duration of stay of three days. A mortality rate of 16.52% was seen, with 17.11% in hematological malignancies and 15.38% in solid tumors.

CONCLUSIONS

This study showed an increasing prevalence of Gram-negative bacterial infection in patients with febrile neutropenia. It also shows a high prevalence of antibiotic resistance in microbes in febrile neutropenia. Larger multi-hospital studies are required to better understand the microbiological profile of febrile neutropenia and identify the developing antimicrobial resistance trends.

The Risk of Rectal Temperature Measurement in Neutropenia

BACKGROUND

Avoiding rectal thermometry is recommended in patients with neutropenic fever. Permeability of the anal mucosa may result in a higher risk of bacteremia in these patients. Still, this recommendation is based on only a few studies.

METHODS

This retrospective study included all individuals admitted to our emergency department during 2014-2017 with afebrile (body temperature <38.3°C) neutropenia (neutrophil count <500 cells/microL) who were over the age of 18. Patients were stratified by the presence or absence of a rectal temperature measurement. The primary outcome was bacteremia during the first five days of index hospitalization; the secondary outcome was in-hospital mortality.

RESULTS

The study included 40 patients with rectal temperature measurements and 407 patients whose temperatures were only measured orally. Among patients with oral temperature measurements, 10.6% had bacteremia, compared to 5.1% among patients who had rectal temperature measurements. Rectal temperature measurement was not associated with bacteremia, neither in non-matched (odds ratio [OR] 0.36, 95% confidence interval [CI] 0.07-1.77) nor in matched cohort analyses (OR 0.37, 95% CI 0.04-3.29). In-hospital mortality was also similar between the groups.

CONCLUSIONS

Patients with neutropenia who had their temperature taken using a rectal thermometer did not experience a higher frequency of events of documented bacteremia or increased in-hospital mortality.

Rare Yeasts in Latin America: Uncommon Yet Meaningful

Systemic infections caused by rare yeasts are increasing given the rise in immunocompromised or seriously ill patients. Even though globally, the clinical significance of these emerging opportunistic yeasts is increasingly being recognized, less is known about the epidemiology of rare yeasts in Latin America. This review collects, analyzes, and contributes demographic and clinical data from 495 cases of infection caused by rare yeasts in the region. Among all cases, 32 species of rare yeasts, distributed in 12 genera, have been reported in 8 Latin American countries, with Trichosporon asahii (49.5%), Rhodotorula mucilaginosa (11.1%), and Saccharomyces cerevisiae (7.8%) the most common species found. Patients were mostly male (58.3%), from neonates to 84 years of age. Statistically, surgery and antibiotic use were associated with higher rates of Trichosporon infections, while central venous catheter, leukemia, and cancer were associated with higher rates of Rhodotorula infections. From all cases, fungemia was the predominant diagnosis (50.3%). Patients were mostly treated with amphotericin B (58.7%). Crude mortality was 40.8%, with a higher risk of death from fungemia and T. asahii infections. Culture was the main diagnostic methodology. Antifungal resistance to one or more drugs was reported in various species of rare yeasts.

Current Sites of Infections and Types of Microorganisms in Patient with Febrile Neutropenia in Hematological Wards – Single Center Study

BACKGROUND: Febrile neutropenia occurs in more than 80% of patients with hematological malignances specially after chemotherapy cycles and an infectious source is identified in approximately 20–30%. Various bacterial, viral, and fungal pathogen contribute to the development of neutropenic fever and without prompt antibiotic therapy mortality rate can be as high as 70%. AIM: The objective of the study was to document the current sites of infection in patients with febrile neutropenia in hematological ward in Baghdad Teaching Hospital, the microorganisms and antibiotic susceptibly in culture positive cases and mortality rate in 1 week and 4 weeks after episode of fever. PATIENTS AND METHODS: One hundred cases of febrile neutropenia were evaluated in Hematological Ward of Baghdad Teaching Hospital from January 2019 to January 2020. Detailed history, physical examination, and laboratory investigations were conducted and statistical analysis of the results was done. RESULTS: One hundred cases of febrile neutropenia, mean age of presentation was 41.56 ± 10.5 years. Acute myeloid leukemia (36%) and acute lymphocytic leukemia (26%) were the most common underlying hematological disorder, followed by Aplastic Anemia, Non-Hodgkin Lymphoma, and Hodgkin Lymphoma. Temperature ranged from 38°C to 39°C with mean temperature of 38.4°C and most of the patient presented with short duration of fever, 57% had absolute neutrophil count below 150 cells/μL with mean duration of neutropenia was 14.01 days. Respiratory tract was the most common site of infection (52%) followed by urinary tract (18%) and in 16% had no obvious focus of infection. Thirty percent of cases were culture Gram-positive and Gram-negative microorganism which were more common 62.9% which were generally sensitive to Aminoglycosides while Gram-positive microorganism constituted 29.6% of isolated bacteria and were generally sensitive to vancomycin. No mortality documented 1 and 4 weeks after fever. CONCLUSION: We concluded that the most frequent sites of infection in patient with febrile neutropenia were respiratory tract followed by urinary tract infection, while 16% had undetermined source of infection. Thirty percent of patients had a positive blood culture with Escherichia coli being the most common infecting microorganism, Gram-negative microorganisms were more common than Gram-positive microorganism and fungal infection constituted about 6% of growth. Significant association was found between the fever and longer duration of neutropenia and the greater severity of neutropenia was observed. No mortality related to febrile neutropenia was documented.

Role of urine studies in asymptomatic febrile neutropenic patients presenting to the emergency department

BACKGROUND

The role of urine studies in the detection of urinary tract infection (UTI) in febrile neutropenic patients with urinary symptoms (having a urinary catheter or having a positive urine analysis) is inarguable. However, the evidence is scarce regarding the indication for urine studies in asymptomatic (i.e., without urinary symptoms) patients with febrile neutropenia (FN) presenting to the emergency department (ED). The aim of this study is to evaluate the need for obtaining urine studies in asymptomatic febrile neutropenic patients.

METHODS

This was a retrospective cohort study conducted on adult cancer patients who presented to the ED with FN and had no urinary symptoms. We included all ED presentations of eligible patients between January 2013 and September 2018. Student's t-test and Wilcoxon rank-sum test were used for continuous data, while Chi-square and Fisher's exact tests were used for categorical data. Participants were divided into two groups based on their urine culture (UC) results: negative and positive UCs. Two cut-offs were used for positive UC results: ≥10⁵ cfu/mL and ≥10⁴ cfu/mL.

RESULTS

We included 284 patients in our study. The age of our patient population was 48.5±18.5 years. More than two-thirds (68.7%) of patients had severe neutropenia, while only 3.9% and 9.9% of the patients had positive UCs at ≥10⁵ cfu/mL and ≥10⁴ cfu/mL, respectively. UCs were expectedly positive in most patients with urinalysis (UA) abnormalities. However, 27.3% and 32.1% of patients with positive UCs at ≥10⁵ cfu/mL and ≥10⁴ cfu/mL respectively had a normal UA.

CONCLUSIONS

In our study, the incidence of UTI in adult febrile neutropenic cancer patients who present to the ED without urinary symptoms is low. Consequently, routine urine testing may not be warranted in this population, as it adds unnecessary financial burdens on the patients and delays timely management.

Pediatric Febrile Neutropenia: Change in Etiology of Bacteremia, Empiric Choice of Therapy and Clinical Outcomes

BACKGROUND

The optimal choice of initial antibiotic therapy for patients with high-risk febrile neutropenia (FN) in children is unclear and varies by the institution on the basis of local antibiograms and epidemiology of specific pathogens. The authors evaluated the appropriateness of antibiotics for the empiric treatment of FN in pediatric patients with cancer in our institution on the basis of changes in the epidemiology of organisms isolated from blood cultures (BCx).

METHODS

The authors conducted a retrospective medical record review of pediatric patients who received any oncology care (including patients with cancer and patients who had stem cell transplant) at University of Chicago Medicine Comer Children's Hospitals (March 2009 to December 2016) with a diagnosis of FN who had at least 1 BCx obtained. They reviewed pathogens isolated from BCx and determined whether they were pathogens or contaminants using the Infectious Diseases Society of America (IDSA) guidelines and the team's decision to treat. They investigated the microbiologic spectrum and susceptibility patterns of pathogens causing bacteremia in pediatric FN and whether the empiric therapy chosen may have affected clinical outcomes.

RESULTS

A total of 667 FN episodes were identified in 268 patients. BCx were negative in 497 (74.5%) and were determined to be contaminants in 27 (4%). In 143 episodes (21.5%), the BCx were positive for a pathogenic species. Polymicrobial bacteremia was identified in 25 episodes; a total of 176 pathogens were isolated. The majority of pathogens (95/176, 54%) were Gram-positive (GP), whereas 64 of 162 (36%) were Gram-negative (GN), 5 were fungal, and 4 were mycobacterial. The most common GP pathogens were viridans group streptococci (VGS) (n=34, 19.3%), coagulase-negative staphylococci (n=25, 14%), and methicillin-susceptible Staphylococcus aureus (n=12, 6.8%). Of aerobic GN bacilli, 15 (8.5%) were AmpC producers and 3 (1.7%) carried extended-spectrum beta-lactamases. There was no increase in the prevalence of multidrug-resistant GN isolates during the study period. Patients with VGS and multidrug-resistant GN bacteremia were more likely to be admitted to the pediatric intensive care unit [odds ratio (OR), 3.24; P=0.017; and OR, 2.8; P=0.07, respectively]. There were trends toward a higher prevalence of GP pathogens causing bacteremia and the emergence of VGS with decreased penicillin sensitivity. The prevalence of bacteremia with VGS was higher in acute myelogenous leukemia and neuroblastoma (OR, 2.3; P<0.01) than in patients with other solid tumors.

CONCLUSIONS

Empiric antibiotic treatment should be tailored to patients' risk for VGS and multidrug-resistant organisms. Individual hospitals should monitor the pathogens causing FN among patients with cancer to guide choice of empiric therapy.

Safety and efficacy of step-down to oral outpatient treatment versus inpatient antimicrobial treatment in pediatric cancer patients with febrile neutropenia: A noninferiority multicenter randomized clinical trial

BACKGROUND

It has been suggested that low-risk febrile neutropenia (FN) episodes can be treated in a step-down manner in the outpatient setting. This recommendation has been limited to implementation in middle-income countries due to concerns about infrastructure and lack of trained personnel. We aimed to determine whether early step-down to oral antimicrobial outpatient treatment is not inferior in safety and efficacy to inpatient intravenous treatment in children with low-risk FN.

PROCEDURE

A noninferiority randomized controlled clinical trial was conducted in three hospitals in Mexico City. Low-risk FN was identified in children younger than 18 years. After 48 to 72 hours of intravenous treatment, children were randomly allocated to receive outpatient oral treatment (experimental arm, cefixime) or to continue inpatient treatment (standard of care, cefepime). Daily monitoring was performed until neutropenia resolution. The presence of any unfavorable clinical outcome was the endpoint of interest. We performed a noninferiority test for comparison of proportions.

RESULTS

We identified 1237 FN episodes; 117 cases were randomized: 60 to the outpatient group and 57 for continued inpatient treatment. Of the FN episodes, 100% in the outpatient group and 93% in the inpatient group had a favorable outcome (P < 0.001). The mean duration of antibiotics was 4.1 days (SD 2.5; 95% CI, 3.4-4.8 days) in the outpatient group and 4.4 days (SD 2.5; 95% CI, 3.7-5.0 days) in the inpatient group (P = 0.70).

CONCLUSIONS

In our population, step-down oral outpatient treatment of low-risk FN was as safe and effective as inpatient intravenous treatment. Clinical Trials Identifier: NCT04000711.

A retrospective study on Escherichia coli bacteremia in immunocompromised patients: Microbiological features, clinical characteristics, and risk factors for shock and death

Background

To evaluate clinical features, bacterial characteristics, and risk factors for shock and mortality of immunocompromised patients with Escherichia coli bacteremia.

Methods

A nearly 6‐year retrospective study of E coli bacteremia in 188 immunocompromised patients at Xiangya Hospital was conducted. Demographic, clinical, and laboratory data were documented. Phylogenetic background and virulence factors of E coli isolates were detected by polymerase chain reaction. Risk factors for shock and mortality were also investigated.

Results

Of all 188 E coli isolates, most prevalent virulence factors were fimH (91.0%), followed by traT (68.6%) and iutA (67.0%), while papG allele I, gafD, and cdtB were not detected. Phylogenetic group D was dominant (42.0%) among all isolates, and group B2 accounted for 17.6%, while group A and B1 accounted for 28.2% and 12.2%, respectively. In univariate analysis, ibeA and cnf1 were associated with mortality, which were not found in multivariate regression analysis. 22.3% of patients suffered shock, and 30‐day mortality rate was 21.3%. MDR (HR 2.956; 95% CI, 1.091‐8.012) was the only risk factor for shock, while adult (HR 0.239; 95% CI, 0.108‐0.527) was a protective factor. Multivariate analysis revealed that shock (HR 4.268; 95% CI, 2.208‐8.248; P < .001) and Charlson index > 2 (HR 2.073; 95% CI, 1.087‐3.952; P = .027) were associated with fatal outcome.

Conclusions

Escherichia coli bacteremia was highly lethal in immunocompromised patients, and host‐related factors played major roles in poor prognosis, while bacterial determinants had little effect on outcome. This study also provided additional information about the virulence and phylogenetic group characteristics of E coli bacteremia.

Global prevalence of carbapenem resistance in neutropenic patients and association with mortality and carbapenem use: systematic review and meta-analysis

Background

Carbapenem-resistant Gram-negative bacteria are recognized as a cause of difficult-to-treat infections associated with high mortality.

Objectives

To perform a systematic review of currently available data on distribution, characteristics and outcome associated with carbapenem-resistant bloodstream infections in adult neutropenic patients.

Methods

Included studies were identified through Medline, Embase and Cochrane databases between January 1995 and April 2016. Random effect meta-analysis was used to quantify the association between carbapenem resistance and mortality and between carbapenem exposure and resistance.

Results

A total of 30 studies from 21 countries were included. Overall carbapenem resistance varied from 2% to 53% (median 9%) among studies. Infections due to carbapenem-resistant Pseudomonas spp . were reported in 18 (60%) studies showing high median resistance rates (44% of all carbapenem-resistant Gram-negatives and 19% of Pseudomonas isolates). Resistance of Enterobacteriaceae was less commonly reported and bloodstream infections due to carbapenem-resistant Klebsiella spp. were mainly documented from endemic areas (Greece, Italy, Israel). Carbapenem resistance in Acinetobacter spp. was reported in 9 (30%) studies (median resistance 58% of Acinetobacter isolates). Mortality rates ranged from 33% to 71% (median 50%) in patients with carbapenem-resistant infections. Carbapenem resistance appeared to correlate with mortality (OR 4.89, 95% CI 3.30-7.26) and previous exposure to carbapenems (OR 4.63, 95% CI 3.08-6.96).

Conclusions

Carbapenem resistance represents a threat to neutropenic patients. In this group, resistance is likely promoted by previous carbapenem use and leads to high mortality rates. The knowledge of resistance patterns is crucial and can direct clinicians in the use of alternatives to carbapenem-based regimens.

Epedimiologic, clinical profile and factors affecting the outcome in febrile neutropenia

BACKGROUND

Febrile neutropenia (FN) is common in cancer patients particularly hematologic malignancies due to intensive cytotoxic chemotherapy. It is an important cause of morbidity, mortality and treatment delays. The risk is greater in patients with ANC < 500/ mm3 and increases dramatically in those with ANC < 100/ mm3 and duration of neutropenia more than 1 week.

AIMS AND OBJECTIVES

The purpose of this study was to evaluate the incidence, demographic characteristics, clinical profile, mortality, outcome and factors affecting the outcome in patients with febrile neutropenia (FN) admitted at our Center between January 2011 and November 2012.

MATERIALS AND METHODS

All cases of FN admitted in our Institute between January 2011 and November 2012 were analyzed. Data was analyzed using IBM statistic SPSS version 19.

RESULTS

A total of 333 episodes of FN were reviewed. Hematologic malignancies accounted for 299 (89.7%) episodes and 88% of all the episodes had grade 4 neutropenia. There was a significant association noted between high serum bilirubin, creatinine and outcome. Isolation of an organism from blood culture, positive findings on chest X-ray and fungal infection was associated with higher mortality. Association between transfusion requirements and outcome was analyzed and it was observed that patients who had multiple component transfusions vs single component ones were at a significantly higher risk of death. There were only 7 deaths noted among the patient population.

CONCLUSION

Leukemias are the leading cause of FN at our Institute. Higher bilirubin, creatinine, chest imaging favoring pneumonia, positive isolates and multiple transfusions had significant association with mortality. Large scale prospective studies are needed to determine the association of preemptive therapy with higher mortality. The outcome of high risk FN in this study is favorable.

Biomarker candidates for the detection of an infectious etiology of febrile neutropenia

PURPOSE

Infections and subsequent septicemia are major complications in neutropenic patients with hematological malignancies. Here, we identify biomarker candidates for the early detection of an infectious origin, and monitoring of febrile neutropenia (FN).

METHODS

Proteome, metabolome, and conventional biomarkers from 20 patients with febrile neutropenia without proven infection (FNPI) were compared to 28 patients with proven infection, including 17 patients with bacteremia.

RESULTS

Three peptides (mass to charge ratio 1017.4-1057.3; p-values 0.011-0.024), six proteins (mass to charge ratio 6881-17,215; p-values 0.002-0.004), and six phosphatidylcholines (p-values 0.007-0.037) were identified that differed in FNPI patients compared to patients with infection or bacteremia. Seven of these marker candidates discriminated FNPI from infection at fever onset with higher sensitivity and specificity (ROC-AUC 0.688-0.824) than conventional biomarkers i.e., procalcitonin, C-reactive protein, or interleukin-6 (ROC-AUC 0.535-0.672). In a post hoc analysis, monitoring the time course of four lysophosphatidylcholines, threonine, and tryptophan allowed for discrimination of patients with or without resolution of FN (ROC-AUC 0.648-0.919) with higher accuracy compared to conventional markers (ROC-AUC 0.514-0.871).

CONCLUSIONS

Twenty-one promising biomarker candidates for the early detection of an infectious origin or for monitoring the course of FN were found which might overcome known shortcomings of conventional markers.

Diagnosis of bacteremia in pediatric oncologic patients by in-house real-time PCR

Background

Infections are the major cause of morbidity and mortality in children with cancer. Gaining a favorable prognosis for these patients depends on selecting the appropriate therapy, which in turn depends on rapid and accurate microbiological diagnosis. This study employed real-time PCR (qPCR) to identify the main pathogens causing bloodstream infection (BSI) in patients treated at the Pediatric Oncology Institute IOP-GRAACC-UNIFESP-Brazil. Antimicrobial resistance genes were also investigated using this methodology.

Methods

A total of 248 samples from BACTEC® blood culture bottles and 99 whole-blood samples collected in tubes containing EDTA K2 Gel were isolated from 137 patients. All samples were screened by specific Gram probes for multiplex qPCR. Seventeen sequences were evaluated using gender-specific TaqMan probes and the resistance genes bla_SHV, bla_TEM, bla_CTX, bla_KPC, bla_IMP, bla_SPM, bla_VIM, vanA, vanB and mecA were detected using the SYBR Green method.

Results

Positive qPCR results were obtained in 112 of the blood culture bottles (112/124), and 90 % agreement was observed between phenotypic and molecular microbial detection methods. For bacterial and fungal identification, the performance test showed: sensitivity 87 %; specificity 91 %; NPV 90 %; PPV 89 % and accuracy of 89 % when compared with the phenotypic method. The mecA gene was detected in 37 samples, extended-spectrum β-lactamases were detected in six samples and metallo-β-lactamase coding genes in four samples, with 60 % concordance between the two methods. The qPCR on whole blood detected eight samples possessing the mecA gene and one sample harboring the vanB gene. The bla_KPC, bla_VIM, bla_IMP and bla_SHV genes were not detected in this study.

Conclusion

Real-time PCR is a useful tool in the early identification of pathogens and antimicrobial resistance genes from bloodstream infections of pediatric oncologic patients.

New Insight on Epidemiology and Management of Bacterial Bloodstream Infection in Patients with Hematological Malignancies

Bloodstream infections (BSI) are a significant cause of morbidity and mortality in onco-hematologic patients. The Gram-negative bacteria were the main responsible for the febrile neutropenia in the sixties; their impact declined due to the use of fluoroquinolone prophylaxis. This situation was followed by the gradual emergence of Gram-positive bacteria also following the increased use of intravascular devices and the introduction of new chemotherapeutic strategies. In the last decade, the Gram-negative etiology is raising again because of the emergence of resistant strains that make questionable the usefulness of current strategies for prophylaxis and empirical treatment. Gram-negative BSI attributable mortality is relevant, and the appropriate empirical treatment significantly improves the prognosis; on the other hand the adequate delayed treatment of Gram-positive BSI does not seem to have a high impact on survival. The clinician has to be aware of the epidemiology of his institution and colonizations of his patients to choose the most appropriate empiric therapy. In a setting of high endemicity of multidrug-resistant infections also the choice of targeted therapy can be a challenge, often requiring strategies based on off-label prescriptions and low grade evidence.

In this review, we summarize the current evidence for the best targeted therapies for difficult to treat bacteria BSIs and future perspectives in this topic. We also provide a flow chart for a rational approach to the empirical treatment of febrile neutropenia in a multidrug resistant, high prevalence setting.

Outcomes of Nosocomial Bloodstream Infections in Adult Neutropenic Patients: A Prospective Cohort and Matched Case-Control Study

Objective:

To examine the clinical and epidemiologic features, excess length of stay, extra costs, and mortality attributable to bloodstream infection (BSI) in neutropenic patients with hematologic malignancies.

Design:

Prospective cohort and matched case-control study.

Patients:

All adult neutropenic patients with hematologic malignancies admitted to Cologne University Hospital between May 1, 1997, and April 30, 1998, were prospectively observed. Case-patients were defined as patients with nosocomial BSI; control-patients were selected among patients without BSI.

Results:

During the study period, the BSI rate in neutropenic patients was 14.3 per 100 neutropenic episodes. Eighty-four case-patients were included. Matching was successful for 96% of the cohort; 81 matched pairs were studied. The mean total length of stay was significantly longer for patients with BSI than for control-patients (37 vs 29 days;P= .002). Extra costs attributable to the infection averaged $3,200 (U.S.) per patient. The crude mortality rates of case-patients and control-patients were 16% and 4%, respectively (P= .013), with an attributable mortality of 12% (odds ratio, 11). Eighty-seven percent of patients met the criteria for sepsis according to the American College of Chest Physicians/Society of Critical Care Medicine. Severe sepsis or septic shock occurred in 13% of patients and was correlated with mortality (55% vs 10% in patients without severe sepsis or septic shock;P=.01).

Conclusions:

Nosocomial BSI in neutropenic patients is significantly associated with an excess length of hospital stay, extra costs, and excess mortality. Severe sepsis and septic shock are closely correlated with an adverse outcome.

Evaluation of a PCR method to determine the clinical significance of blood cultures with Staphylococcus epidermidis in patients with hematological malignancies

The aim was to investigate whether the detection and quantification of Staphylococcus epidermidis DNA in blood could distinguish S. epidermidis blood stream infections (BSIs) from blood culture contaminations in patients with hematological malignancies. The hld gene was chosen to identify S. epidermidis DNA and DNA in blood samples was detected by real-time PCR. Blood samples were obtained simultaneously with blood cultures positive for S. epidermidis (n = 30), during blood culture-negative episodes (n = 10) and episodes of bacteremia with other bacteria than S. epidermidis (n = 4) and from healthy blood donors (n = 10). In addition, DNA from S. epidermidis and a selection of other bacterial species were analyzed. Three different sets of criteria were used to classify episodes with positive blood cultures with S. epidermidis as BSIs or contaminations. All DNA preparations from S. epidermidis (n = 48) were hld-positive, but other bacterial species (n = 13) were negative. Sixteen (53%) of 30 blood samples from patients with blood cultures positive for S. epidermidis were hld-positive, but none of the controls. There was no clear association between a positive hld PCR and episodes interpreted as BSIs. In conclusion, hld PCR failed to distinguish S. epidermidis BSIs from blood culture contaminations in patients with hematological malignancies.

Bloodstream infections in patients with or without cancer in a large community hospital

PURPOSE

Cancer is associated with an increased risk of acquiring bloodstream infection (BSIs). Most knowledge on pathogens and outcome are derived from specialised cancer centres. We here sought to compare causative micro-organisms in BSIs in patients with or without cancer in a 600-bed teaching community hospital.

METHODS

We analysed all positive blood cultures from adult patients between January 2005 and January 2011.

RESULTS

A total of 4,918 episodes of BSI occurred in 2,891 patients, of whom 13.4% had a diagnosis of cancer (85.5% with a solid tumour). In both patient groups, Gram-positive isolates were more prevalent (58.7 and 61.4% in patients with and without cancer, respectively) than Gram-negative isolates (31.8 and 32.3%, respectively). Amongst Gram-positive organisms, coagulase-negative staphylococci, Staphylococcus aureus and enterococci were the most frequently isolated in both patient groups; in cancer patients, twice as many BSIs were caused by Enterococcus faecalis and E. faecium. Amongst Gram-negative organisms, Escherichia coli was the most common isolate; in cancer patients, twice as many BSIs were caused by Pseudomonas aeruginosa and Enterobacter cloacae. Yeasts were grown from 3.0% of blood cultures from cancer patients compared to 1.5% of cultures from non-cancer patients. Cancer patients had a 90-day mortality of 35.8% following BSI compared to 23.5% in patients without cancer.

CONCLUSION

These data demonstrate distinct BSI pathogens and impaired outcomes in patients with cancer in the setting of a large community teaching hospital.

Derivation and validation of a scoring system to identify patients with bacteremia and hematological malignancies at higher risk for mortality

BACKGROUND

The aim of this study was to develop and validate a reliable clinical prediction rule that could be employed to identify patients at higher likelihood of mortality among those with hematological malignancies (HMs) and bacterial bloodstream infections (BBSIs).

METHODS AND FINDINGS

We conducted a retrospective cohort study in nine Italian hematological units. The derivation cohort consisted of adult patients with BBSI and HMs admitted to the Catholic University Hospital (Rome) between January 2002 and December 2008. Survivors and nonsurvivors were compared to identify predictors of 30-day mortality. The validation cohort consisted of patients hospitalized with BBSI and HMs who were admitted in 8 other Italian hematological units between January 2009 and December 2010. The inclusion and exclusion criteria were identical for both cohorts, with type and stage of HMs used as matching criteria. In the derivation set (247 episodes), the multivariate analysis yielded the following significant mortality-related risk factors acute renal failure (Odds Ratio [OR] 6.44, Confidential Interval [CI], 2.36-17.57, P<0.001); severe neutropenia (absolute neutrophil count <100/mm(3)) (OR 4.38, CI, 2.04-9.43, P<0.001); nosocomial infection (OR, 3.73, CI, 1.36-10.22, P = 0.01); age ≥65 years (OR, 3.42, CI, 1.49-7.80, P = 0.003); and Charlson Comorbidity Index ≥4 (OR, 3.01, CI 1.36-6.65, P = 0.006). The variables unable to be evaluated at that time (for example, prolonged neutropenia) were not included in the final logistic model. The equal-weight risk score model, which assigned 1 point to each risk factor, yielded good-excellent discrimination in both cohorts, with areas under the receiver operating curve of 0.83 versus 0.93 (derivation versus validation) and good calibration (Hosmer-Lemshow P = 0.16 versus 0.75).

CONCLUSIONS

The risk index accurately identifies patients with HMs and BBSIs at high risk for mortality; a better initial predictive approach may yield better therapeutic decisions for these patients, with an eventual reduction in mortality.

Nosocomial infections in leukemic and solid-tumor cancer patients: distribution, outcome and microbial spectrum of anaerobes

Aims: Nosocomial infections cause significant morbidity and mortality in cancer patients. As a result of their debilitated immune system, cancer patients are likely candidates for colonization with anaerobes. We sought to compare the distribution of nosocomial infections in neutropenic and non-neutropenic cancer patients and to calculate the associated mortality rates. Material & methods: This is the first study to demonstrate a complete microbial spectrum of anaerobes in various infection sites in hospitalized cancer patients. Results: Frequencies of bloodstream infections (BSI), respiratory tract infections (RTI), and GI tract infections (GITI) were significantly higher in neutropenic cancer patients (p < 0.01). Conversely, urinary tract infection (UTI) and skin infection (SI) rates were significantly higher in non-neutropenic cancer patients (p < 0.01). Mortalities attributed to BSI, UTI, RTI, SI, and GITI occured at the respective percentage frequencies of 12.5%, 11.5%, 10.4%, 7.7% and 4.9%. Anaerobes constituted 4.7% of total isolates, and were recovered from SI (66.3%) and GITI (33.6%), but not respiratory tract, urine, or blood. Most anaerobes (79.2%) were isolated from solid-tumor patients. The most common infection in cancer patients was RTI (55.8%), mainly in leukemic patients, followed by SI (18%), only in solid-tumor patients, GITI (9.7%), BSI (9.4%), and UTI (7.1%). The most frequent isolates of Fusobacterium necrophorum (32.7%) and Eubacterium lentum (23.8%) were mostly recovered from solid-tumor patients. These were followed by Clostridium perfringens (11.9%), Clostridium difficile (10.9%), Eubacterium limosum (5.9%), and Veillonella parvula (5%). Conclusion: Control measures are needed to minimize risks of nosocomial infection outbreaks by anaerobes. Continuous monitoring of the presence of anaerobes in various infection sites in hospitalized cancer patients is needed in order to be able to provide the best supportive care for cancer patients.

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.

Hematological: Low all-cause mortality and low occurrence of antimicrobial resistance in hematological patients with bacteremia receiving no antibacterial prophylaxis: a single-center study

BACKGROUND

Bacteremia is a major cause of morbidity and mortality in patients with hematological malignancies.

OBJECTIVES

The aim of this study was to define temporal trends in species distribution, antimicrobial susceptibility, and all-cause mortality in bacteremic hospitalized patients receiving no antibacterial prophylaxis during chemotherapy-induced neutropenia.

METHODS

A total of 677 clinical episodes of bacteremia were identified in 463 patients during 2002-2008, and the results were compared with those published from the same institution during 1980-86 and 1988-2001. No major changes in patient selection were introduced during this period.

RESULTS

Between 2002 and 2008, the dominating pathogens were Escherichia coli (18%), coagulase-negative staphylococci (15%), viridans streptococci (14%), Klebsiella spp. (10%), and Enterococcus faecium (8%). The 7-d crude mortality rate was 5.2%. Polymicrobial bacteremia was seen in 25.7% of the patients who died within 7 d and in 13.1% of the survivors (P = 0.04). Acquired resistance was rarely observed, but a statistically significant increase in ciprofloxacin resistance in E. coli was observed. Comparing 2002-2008 with historical data from the same institution, the proportion of Gram-positive isolates remained stable at 53-55% from 1988.

CONCLUSIONS

The avoidance of fluoroquinolone prophylaxis may have contributed to a stable proportion of Gram-positive bacteremia. The crude mortality was low in an international perspective. Acquired resistance was uncommon, but ciprofloxacin resistance in E. coli increased significantly. We believe that an indiscriminate use of antibacterial prophylaxis could be avoided in neutropenic patients without a negative impact on mortality.

P. aeruginosa bloodstream infections among hematological patients: an old or new question?

Pseudomonas aeruginosa is a well-known cause of severe and potentially life-threatening infections among hematological patients. A prospective epidemiological surveillance program ongoing at our Hematology Unit revealed an increase over time of P. aeruginosa bloodstream infections (BSI). Their impact on outcome and antibiotic susceptibility was analyzed. BSI which consecutively occurred at our institution during a 70-month period were evaluated and correlated with type of pathogen, status of underlying disease, neutropenia, previous antibiotic therapy, resistance to antibiotics, and outcome. During the observation period, 441 BSI were recorded. Frequency of Gram-negative BSI was higher than that of other pathogens (57.3%). Overall, 66 P. aeruginosa BSI were recorded; 22 out of 66 were multiresistant (MR P. aeruginosa). Thirty-day mortality for all BSI was 11.3%; it was 27.3% for P. aeruginosa BSI and 36.4% for MR P. aeruginosa. At multivariate analysis, only active hematological disease and P. aeruginosa BSI were associated to an increased risk of death. For MR P. aeruginosa, BSI mortality was 83.3% vs. 18.8% when empiric therapy included or not an antibiotic with in vitro activity against P. aeruginosa (p=0.011). Together with active disease, the emergence of P. aeruginosa BSI, particularly if multiresistant, was responsible for an increased risk of death among hematological patients at our institution. In this scenario, reconsidering the type of combination antibiotic therapy to be used as empiric treatment of neutropenic fever was worthwhile.

Management of gram-positive bacterial infections in patients with cancer

Bacterial infections, particularly those due to gram-positive bacteria, continue to predominate in patients with cancer. Coagulase-negative and coagulase-positive staphylococci and enterococci remain as common pathogenic microorganisms. Clostridium difficile has emerged as a significant pathogen. Major clinical syndromes include vascular catheter-related infection, febrile neutropenia, diarrhea and colitis. Rising antimicrobial resistance among gram-positive bacteria is of serious concern. The clinical utility of penicillin against streptococci and vancomycin against coagulase-negative and coagulase-positive staphylococci and enterococci may be rapidly diminishing. Liberal empiric use of vancomycin during neutropenic fever needs careful reconsideration. Newer promising anti-gram-positive bacterial drugs with activity against methicillin-resistant staphylococci include daptomycin, linezolid, tigecycline and telavancin. However, toxicity concerns, limited data in immunocompromised populations and high cost prevent the widespread use of these drugs among patients with cancer.

Nuclear medicine imaging of infection in cancer patients (with emphasis on FDG-PET)

Infections are a common cause of death and an even more common cause of morbidity in cancer patients. Timely and adequate diagnosis of infection is very important. This article provides clinicians as well as nuclear medicine specialists with a concise summary of the most important and widely available nuclear medicine imaging techniques for infectious and inflammatory diseases in cancer patients with an emphasis on fluorodeoxyglucose positron emission tomography (FDG-PET). ⁶⁷Ga-citrate has many unfavorable characteristics, and the development of newer radiopharmaceuticals has resulted in the replacement of ⁶⁷Ga-citrate scintigraphy by scintigraphy with labeled leukocytes or FDG-PET for the majority of conditions. The sensitivity of labeled leukocyte scintigraphy in non-neutropenic cancer patients is comparable with that in patients without malignancy. The specificity, however, is lower because of the uptake of labeled leukocytes in many primary tumors and metastases, most probably as a result of their inflammatory component. In addition, labeled leukocyte scintigraphy cannot be used for febrile neutropenia because of the inability to harvest sufficient peripheral leukocytes for in vitro labeling. FDG-PET has several advantages over these conventional scintigraphic techniques. FDG-PET has shown its usefulness in diagnosing septic thrombophlebitis in cancer patients. It has also been shown that imaging of infectious processes using FDG-PET is possible in patients with severe neutropenia. Although larger prospective studies examining the value of FDG-PET in cancer patients suspected of infection, especially in those with febrile neutropenia, are needed, FDG-PET appears to be the most promising scintigraphic technique for the diagnosis of infection in this patient group.

A prospective study of febrile episodes in inpatient children on chemotherapy

In 538 febrile episodes in 188 children enrolled prospectively, 62% of children were neutropenic and 86% had infection-related fever. Respiratory infection was the commonest febrile cause (60%). Bacteremia occurred more often in neutropenic than non-neutropenic episodes (20% vs. 3%) and was accompanied significantly more with shiver, lassitude, and decreased dorsum pedis pulse. About 65% of blood isolates were Gram-negative bacilli, which differs from the observations in western countries.

Microbial etiology of febrile neutropenia

Bacterial and fungal infections are a major cause of morbidity and mortality among neutropenic patients. The choice of empiric antimicrobial regimen is based on susceptibility pattern of locally prevalent pathogens. From 64 febrile neutropenic patients with clinical sepsis, blood and other appropriate clinical specimens were processed to determine bacterial and fungal spectrum and their antimicrobial susceptibility pattern. Risk factors for developing sepsis were determined by case-control study. 68 organisms were recovered. Fifteen (22.05%) were Gram-positive cocci with predominance of methicillin Sensitive S. aureus (10.29%), 47 (69.11%) were Gram-negative rods with predominance of Klebsiella pneumoniae (30.88%) and four were Non albicans Candida. 81% and 60% of Klebsiella and E. coli were ESBL producers. All species of Candida were sensitive to amphoterecin B and voriconazole. Duration and extent of neutropenia, chemotherapy, immunosuppressive therapy, altered mucosal barriers and presence of central venous lines were statistically significant risk factors for developing sepsis. Gram-negative bacteria were the predominant isolates. The choice of therapy in neutropenic patients should be formulated based on local spectrum of microbes and local and regional resistance patterns.

Invasive aspergillosis in developing countries

To review invasive aspergillosis (IA) in developing countries, we included those countries, which are mentioned in the document of the International Monetary Fund (IMF), called the Emerging and Developing Economies List, 2009. A PubMed/Medline literature search was performed for studies concerning IA reported during 1970 through March 2010 from these countries. IA is an important cause of morbidity and mortality of hospitalized patients of developing countries, though the exact frequency of the disease is not known due to inadequate reporting and facilities to diagnose. Only a handful of centers from India, China, Thailand, Pakistan, Bangladesh, Sri Lanka, Malaysia, Iran, Iraq, Saudi Arabia, Egypt, Sudan, South Africa, Turkey, Hungary, Brazil, Chile, Colombia, and Argentina had reported case series of IA. As sub-optimum hospital care practice, hospital renovation work in the vicinity of immunocompromised patients, overuse or misuse of steroids and broad-spectrum antibiotics, use of contaminated infusion sets/fluid, and increase in intravenous drug abusers have been reported from those countries, it is expected to find a high rate of IA among patients with high risk, though hard data is missing in most situations. Besides classical risk factors for IA, liver failure, chronic obstructive pulmonary disease, diabetes, and tuberculosis are the newly recognized underlying diseases associated with IA. In Asia, Africa and Middle East sino-orbital or cerebral aspergillosis, and Aspergillus endophthalmitis are emerging diseases and Aspergillus flavus is the predominant species isolated from these infections. The high frequency of A. flavus isolation from these patients may be due to higher prevalence of the fungus in the environment. Cerebral aspergillosis cases are largely due to an extension of the lesion from invasive Aspergillus sinusitis. The majority of the centers rely on conventional techniques including direct microscopy, histopathology, and culture to diagnose IA. Galactomannan, β-D glucan test, and DNA detection in IA are available only in a few centers. Mortality of the patients with IA is very high due to delays in diagnosis and therapy. Antifungal use is largely restricted to amphotericin B deoxycholate and itraconazole, though other anti-Aspergillus antifungal agents are available in those countries. Clinicians are aware of good outcome after use of voriconazole/liposomal amphotericin B/caspofungin, but they are forced to use amphotericin B deoxycholate or itraconazole in public-sector hospitals due to economic reasons.

Epidemiology of bloodstream infections in patients with haematological malignancies with and without neutropenia

All bacterial isolates from 7058 patients admitted to haemato-oncology wards at National Taiwan University Hospital between 2002 and 2006 were characterized. In total 1307 non-duplicate bloodstream isolates were made from all patients with haematological malignancy; 853 (65%) of these were from neutropenic patients. Gram-negative bacteria predominated (60%) in neutropenic isolates with Escherichia coli (12%), Klebsiella pneumoniae (10%), Acinetobacter calcoaceticus-baumannii complex (6%), and Stenotrophomonas maltophilia (6%) the most frequent. Coagulase-negative staphylococci (19%) and Staphylococcus aureus (4%) were the most common Gram-positive pathogens. Resistance to ciprofloxacin was found in 50% of E. coli and 20% of K. pneumoniae isolates from neutropenic patients. Extensively drug-resistant A. calcoaceticus-baumannii complex and vancomycin-resistant enterococci were also found during the study period. Emerging antimicrobial resistant pathogens are an increasing threat to neutropenic cancer patients.

Etiology and clinical course of febrile neutropenia in children with cancer

BACKGROUND

The etiology, clinical course, and outcome of fever and neutropenia (FN) in children with cancer using the current FN guidelines and diagnostic resources in the United States have not been well described.

PATIENTS AND METHODS

Medical records of a randomly selected FN episode per patient during 2004-2005 at a pediatric oncology center were reviewed. Patients were managed as per institutional FN guidelines and blood cultures collected in continuously read BACTEC bottles.

RESULTS

Of 337 FN episodes, infection was proven in 86 (25%) and probable in 75 (22%). In all, 177 episodes (53%) were judged fever of unknown origin (FUO). Bacteremia accounted for most (41) of the proven bacterial episodes, with viridans streptococci (13), Pseudomonas spp. (6) and Escherichia coli (6) the most frequently isolated organisms. The median time to positivity of blood cultures was 12 hours (range, 5.4-143.7) with 93% positive within 24 hours of incubation. Viral pathogens were identified in 29 (34%) episodes. Compared with other patients, those with FUO had shorter median duration of fever (0.5 vs. 2.0 d; P<0.0001) and hospitalization (3 vs. 6 d; P<0.0001), longer median duration since last chemotherapy (6.0 vs. 4.0 d; P=0.01), and were less likely to have a diagnosis of acute myelogenous leukemia (11% vs. 22%; P=0.009) or develop a clinical complication (5.1% vs. 24.4%; P<0.0001).

CONCLUSIONS

Despite currently available diagnostic resources, the majority of patients with FN have FUO marked by a low rate of clinical complications and no infection-related mortality. Emergence of viridans streptococci as the most common blood isolate has affected FN treatment recommendations. Study findings will help further development of strategies for risk stratified management of fever with neutropenia in pediatric patients.

Factors associated with mortality in bacteremic patients with hematologic malignancies

We conducted a retrospective cohort study to identify risk factors for mortality in a large cohort of hematologic patients with bacteremia. From 2000 through 2005, bacteremia was diagnosed in 217 patients with hematologic malignancies. The infections were caused only by Gram-positive organisms in 57.1% (124/217) cases and only by Gram-negative bacteria in 37.8% (82/217); the remaining 5.1% (11/217) were polymicrobial. The overall 30-day mortality rate was 20.3% (44/217). In multivariate analysis, significant predictors of mortality were prolonged neutropenia (P < 0.001), acute renal failure (P = 0.002), nosocomial bacteremia (P = 0.009), age >55 years (P = 0.007), and monomicrobial bacteremia due to antibiotic-resistant Gram-negative bacteria (P = 0.009). Reducing fatal outcomes associated with bacteremia in patients with hematologic malignancies is a challenge, and the emergence of resistance to the antimicrobials widely used in this setting is of great concern. Future infection trends must be carefully monitored and treatment guidelines adjusted accordingly.

Genetic characterisation of CTX-M-15-producing Klebsiella pneumoniae and Escherichia coli strains isolated from stem cell transplant patients in Tunisia

Characterisation of extended-spectrum beta-lactamase (ESBL) genes and their genetic environments as well as the presence of integrons were analysed in nine Klebsiella pneumoniae and two Escherichia coli ESBL-positive isolates recovered in the Centre of Bone Marrow Transplantation of Tunisia. All strains harboured the bla(CTX-M-15) gene and presented minimum inhibitory concentrations for cefotaxime and ceftazidime of 256-1024 mg L(-1) and 16-512 mg L(-1), respectively, and eight of them showed different pulsed-field gel electrophoresis patterns. The bla(OXA-1) and bla(TEM-1) genes were detected in eight and ten strains, respectively. In addition, bla(SHV-1), bla(SHV-11) and bla(SHV-27) were found in six, one and one K. pneumoniae strains, respectively. The new variant bla(SHV-103) was characterised in one K. pneumoniae strain. The intI1 gene was detected in eight K. pneumoniae strains and the dfrA5+ereA2 and aadA gene cassettes were found in one and five strains, respectively. All strains harboured a 70 kb plasmid, and its transference in addition to bla(CTX-M-15), bla(TEM-1b) and bla(OXA-1) genes was demonstrated from three K. pneumoniae to E. coli. ISEcp1 and orf477 were located upstream and downstream, respectively, of the bla(CTX-M-15) gene in 10 strains. The occurrence of the bla(CTX-M-15) gene in unrelated strains might have originated from the dissemination of mobile genetic elements in which ISEcp1 may have played an important role.

[Fever and infectious complications in patient with lung cancer]

The respiratory infections are very frequent during lung cancer. Their diagnosis is often difficult because of the various etiologies (cancer, chemotherapy, radiotherapy) and this complexity can make discuss a preliminary bronchial exploration before any therapeutics. When it is about a located infection, germs in cause are often the same that in the community respiratory infections, in particular bacilli Gram negative, and it is thus logical to treat by the penicillin A. In front of an interstitial syndrome, it is necessary to evoke the opportunist infections, which are increasing in patients with cancer because of the multimodality therapeutic and the elongation of the survival. The neutropenic patient must be distinguished because of its specificities. The pulmonary infections lead to an important mortality. According to the patient (advanced age, underlying chronic obstructive pulmonary disease [COPD]) and to the treatment (chemotherapy, pneumonectomy), prevention must be discussed as the pneumococcal and Haemophilus influenzae vaccination.

Bloodstream infections in febrile neutropenic patients at a tertiary care center in Lebanon: a view of the past decade

OBJECTIVES

Previous studies from Lebanon have shown Gram-negative organisms to be the predominant agents in febrile neutropenic patients. The objective of this study was to evaluate the most current epidemiological trends among patients with neutropenic fever.

METHODS

This prospective observational cohort study, the largest to date in the country, was conducted at the American University of Beirut Medical Center between January 2001 and December 2003, with the objective of describing the characteristics of patients with neutropenic fever and to assess temporal trends.

RESULTS

We included 177 episodes of neutropenic fever. The most common underlying malignancy was lymphoma (42.4%). Gastrointestinal and abdominal infections were predominant (31.6%) and 23.7% of cases represented fever of unknown origin. Gram-negative organisms were responsible for 78.8% (26/33) of bloodstream infections compared to 33.3% (11/33) with Gram-positive organisms. The in-hospital mortality rate in this study (12.1%) was considerably lower than in previous years.

CONCLUSIONS

Gram-negative organisms are persistently predominant in our center. In a developing country like Lebanon with limited resources, lower mortality rates commensurate with worldwide reports were successfully achieved in this high-risk patient population. Protocols and guidelines should be adapted to the characteristics of individual institutions to ensure delivery of appropriate care to febrile neutropenic patients.

Granulocyte transfusions in neutropaenic children: a systematic review of the literature

BACKGROUND

Granulocyte transfusions (GTX) have been used for decades in paediatric neutropaenic patients, but uncertainty remains regarding their effectiveness. We reviewed all the paediatric data available on GTX, to gain a insight in to the indications for use, favourable effects and side effects in patients and donors.

METHODS

A comprehensive search was done in MEDLINE, EMBASE, LILACS and CENTRAL (1966 until 2006). All studies including children (1-18 years) who received GTX were included.

RESULTS

A total of 66 observational studies were included:Seven using prophylactic and 59 therapeutic GTX. Of the therapeutic studies 55 reported a proven sepsis caused by Gram-negative bacteria (34%) or fungal disease (48%) as the indication for GTX. Concerning effectiveness 70% survival was reported, but no controlled studies were identified. Side effects were mentioned in 27 studies including mild respiratory symptoms, allergic reactions and infection related complications (CMV). Side effects in the donor were mainly flu-like illness.

DISCUSSION

In this first review covering 30 years of experience on the use of GTX in children, we found no randomised evidence showing a positive benefit risk ratio. The available case reports and cohort studies alert us as to the potential benefits and harms of the use of GTX in neutropaenic children and provides the basis for a well designed trial in children.

Epidemiology of bacteremia and factors associated with multi-drug-resistant gram-negative bacteremia in hematopoietic stem cell transplant recipients

The incidence of Gram-negative bacteremia has increased in hematopoietic stem cell transplant (HSCT) recipients. We prospectively collected data from 13 Brazilian HSCT centers to characterize the epidemiology of bacteremia occurring early post transplant, and to identify factors associated with infection due to multi-drug-resistant (MDR) Gram-negative isolates. MDR was defined as an isolate with resistance to at least two of the following: third- or fourth-generation cephalosporins, carbapenems or piperacillin-tazobactam. Among 411 HSCT, fever occurred in 333, and 91 developed bacteremia (118 isolates): 47% owing to Gram-positive, 37% owing to Gram-negative, and 16% caused by Gram-positive and Gram-negative bacteria. Pseudomonas aeruginosa (22%), Klebsiella pneumoniae (19%) and Escherichia coli (17%) accounted for the majority of Gram-negative isolates, and 37% were MDR. These isolates were recovered from 20 patients, representing 5% of all 411 HSCT and 22% of the episodes with bacteremia. By multivariate analysis, treatment with third-generation cephalosporins (odds ratio (OR) 10.65, 95% confidence interval (CI) 3.75-30.27) and being at one of the hospitals (OR 9.47, 95% CI 2.60-34.40) were associated with infection due to MDR Gram-negative isolates. These findings may have important clinical implications in the decision of giving prophylaxis and selecting the empiric antibiotic regimen.

The Effect of the Neutropenic Diet in the Outpatient Setting: A Pilot Study

PURPOSE/OBJECTIVES

To determine whether use of the neutropenic diet in the outpatient setting decreases the number of febrile admissions and positive blood cultures associated with chemotherapy-induced neutropenia.

DESIGN

Descriptive pilot study.

SETTING

Outpatient chemotherapy unit of a medical center in a major metropolitan area.

SAMPLE

Convenience sample of 28 patients aged 33-67 years beginning treatment with 1 of 13 chemotherapy regimens.

METHODS

Twelve-week prospective study beginning on day 1 of chemotherapy cycle 1. Patients received instructions regarding the neutropenic diet before starting chemotherapy. Adherence assessment telephone calls were made at weeks 6 and 12. Hospital admission charts were reviewed at study completion.

MAIN RESEARCH VARIABLES

Adherence with neutropenic diet, number of febrile admissions, and number of positive blood cultures.

FINDINGS

Sixteen patients were compliant with the neutropenic diet, four of which were admitted for neutropenia with gram-negative rods. No significant differences were found in the rates of febrile admissions or positive blood cultures between compliant and noncompliant patients.

CONCLUSIONS

Clinical significance in this pilot study is related to the time required for diet education, content of diet education regarding food restrictions, and difficulty adhering to diet requirements given the multitude of side effects (e.g., nausea, vomiting, mouth sores, diarrhea) of chemotherapy.

IMPLICATIONS FOR NURSING

No clear evidence exists that the neutropenic diet makes a difference in overall rates of infection. Nursing research to compare the neutropenic diet with a less restrictive food safety education-focused diet is needed to guide clinical practice.

Central venous catheter-associated fungemia due toRhodotorulaspp. – A systematic review

Rhodotorula spp. are emergent opportunistic pathogens, particularly in immunocompromised individuals. They have been associated with endocarditis, peritonitis, meningitis endophthalmitis and catheter-associated fungemia. The aim of this study was to review all cases of central venous catheter-related fungemia due to Rhodotorula spp. reported in the literature in order to determine the best management of this uncommon infection. All patients but one in the 88 cases examined had some form of underlying disease including sixty-nine (78.4%) who had cancer. Rhodotorula mucilaginosa was the species most frequently recovered (75%), followed by Rhodotorula glutinis (6%). Amphotericin B deoxycholate was the most common antifungal agent used as treatment and the overall mortality was 9.1% in this review. This fungemia is a rare disease which can be found in immunocompromised and in the intensive care patients. The use of specific antifungal therapy may be associated with an increase in the survival. It should be noted that Rhodotorula spp. is resistant to fluconazole.

Bacteremias: a leading cause of death

Bloodstream infections (BSIs), recognized to be a major cause of morbidity and mortality globally, are increasing in incidence. The reported rates of crude and attributable mortality vary, possibly due to heterogeneity in patient populations and methodology. Few studies, however, have focused on pathogen-specific attributable mortality. These studies include S. aureus, coagulase-negative staphylococci and enterococcus. Other studies of attributable mortality have been conducted in select populations such as nosocomial and community-acquired cohorts, intensive care units, neutropenic patients, and HIV-positive patients. Regrettably, despite advances in treatment and intensive care facilities, mortality remains high.