A prospective study of characteristics and outcomes of bacteremia in patients with solid organ or hematologic malignancies

Clinical and Epidemiological Characteristics of Bloodstream Infections in Head and Neck Cancer Patients: A Decadal Observational Study

This retrospective study aims to describe the clinico-epidemiological characteristics of bloodstream infections (BSIs) and the risk factors in patients with head and neck cancer (n = 227) treated at the Department of Otolaryngology, Head and Neck Surgery, Tohoku University Hospital between April 2011 and March 2021. Overall, 23.3% of blood cultures were positive. In the culture-positive group, catheter-related bloodstream infections (CRBSIs) were the most common (38.8%), followed by respiratory tract infections (19.4%), and catheter-associated urinary tract infections (6.0%). Methicillin-resistant Staphylococcus aureus (26.9%), Staphylococcus epidermidis (17.9%), and Pseudomonas aeruginosa (10.4%) infections were common. The most frequent treatment for head and neck cancer was surgery (23.9%), followed by treatment interval or palliative care (19.4%), and single radiotherapy (13.4%). The 30-day mortality rate was significantly higher in the BSI than in the non-BSI group (10.4% vs. 1.8%, respectively). CRBSIs are the most frequent source of BSIs in patients with head and neck cancer. In conclusion, central venous catheters or port insertion should be used for a short period to prevent CRBSIs. The risk of developing BSI should be considered in patients with pneumonia. Understanding the epidemiology of BSIs is crucial for diagnosing, preventing, and controlling infections in patients with head and neck cancer.

Clinical Analysis of Bloodstream Infection of Escherichia coli in Patients with Pancreatic Cancer from 2011 to 2019

Background

Pancreatic cancer patients were particularly predisposed to develop Escherichia coli (E. coli) bloodstream infection (BSI); however, little information is currently available. We set out to find E. coli BSI's risk factors in pancreatic cancer to provide valuable experience.

Methods

We retrospectively analyzed the clinical data of pancreatic cancer patients (31 cases with E. coli BSI and 93 cases without BSI) by a case-control study. SPSS 17.0 was adopted to perform univariate and multivariate analyses. Bacterial resistance analysis was performed by Whonet 5.6.

Results

Hospitalization days ≥7 days, number of admissions ≥2 times, surgery, chemotherapy, the type of antibiotics used ≥2 species, albumin<40.0 g/L, and prealbumin < 0.2 g/L were the potential risk factors for pancreatic cancer patients with E. coli BSI (P < 0.1). Multivariate logistic regression showed hospitalization days ≥7 days (OR = 11.196, 95% CI = 0.024–0.333, P < 0.001), surgery (OR = 32.053, 95% CI = 0.007–0.137, P < 0.001), and chemotherapy (OR = 6.174, 95% CI = 0.038–0.688, P=0.014) were the independent risk factors for E. coli BSI of pancreatic cancer patients. E. coli resistant to carbapenems was rare; they were susceptible to cephamycin and piperacillin/tazobactam. The 90-day mortality rate of the infected group was significantly higher than the control group (41.9% versus 8.6%, P < 0.001).

Conclusions

Hospitalization days ≥7 days, surgery, and chemotherapy are the independent risk factors for E. coli BSI of pancreatic cancer patients, which allows us to identify patients at potential risk and perform preventive treatment in time.

Clinical characteristics and outcome of 125 polymicrobial bloodstream infections in hematological patients: an 11-year epidemiologic survey

BACKGROUND

Polymicrobial bloodstream infections (pBSI) occurring in hematological patients are still poorly understood, and specific information are very limited.

OBJECTIVES AND METHODS

In this epidemiologic survey, we describe clinical characteristics and outcome of 125 consecutive pBSI occurred in oncohematological patients. Polymicrobial bloodstream infections (pBSI) were defined with the isolation of 2 or more bacteria from blood culture specimens obtained within 72 h.

RESULTS

Over an 11-year period, we documented 500 bacterial bloodstream infections (BSI) in 4542 hospital admissions and 25% (125) of these were pBSI. Most common underlying hematological disease was acute myeloid leukemia and 89% of patients had severe neutropenia. Fifty pBSI (40%) occurred in patients undergoing a stem cell transplantation (SCT), mostly within 30 days from transplant (42/50-84%). Principal bacterial association was Gram-positive plus Gram-negative (57%). Resolution rate of pBSI was 82%, without differences between SCT and non-SCT cases. pBSI-related mortality was 15% (6% in SCT cases). Septic shock occurred in 16% of cases and septic shock-related mortality was 65% (75% in SCT cases and 63% in non-SCT cases; p = 0.6). Multidrug-resistant (MDR) bacteria were involved in 22% of pBSI and the MDR-pBSI-related mortality was significantly higher in SCT patients (p = 0.007).

CONCLUSIONS

This observational study highlights that pBSI is not a rare bloodstream infectious complication in oncohematological patients. pBSI-related mortality is lower than 20%, but, if septic shock occurs, mortality reaches 65%. MDR bacteria were involved in 22% of cases and pBSI-MDR-related mortality was significantly higher in SCT patients.

Healthcare-associated blood stream infections in hematological patients in Finland during the years 2006-2016

OBJECTIVES

The aim was to identify the clinical characteristics, outcome, and antimicrobial susceptibility of healthcare-associated bloodstream infections (BSIs) in hematological patients.

METHODS

This retrospectively collected laboratory-based surveillance data include 3404 healthcare-associated BSIs in 2296 patients with a hematological malignancy in hospitals participating in the Finnish Hospital Infection Program from January 1, 2006, to December 31, 2016.

RESULTS

The most common underlying diseases were acute myelogenous leukemia (35%) and non-Hodgkin lymphoma (22%). Gram-positive organisms accounted for 60%-46% and gram-negative organisms for 24%-36% of BSIs in 2006-2016. The most common causative organism was coagulase-negative staphylococci (CoNS) (n = 731). The 7- and 28-day case fatality rates were 5.2% and 11.4%, respectively, and was highest in BSIs caused by Candida species (10.8% and 30.8%). The median age of patients increased from 59 years in 2006-2008 to 62 years in 2015-2016 (P < .01). Five percent of S aureus isolates were resistant to methicillin and five percent of Pseudomonas aeruginosa isolates were multidrug-resistant. Four percent of Klebsiella and seven percent of E coli isolates were resistant to ceftazidime.

CONCLUSIONS

The proportion of gram-positive bacteria decreased and gram-negative bacteria increased over time. The case fatality rate was low and the median age of patients increased during the study.

Evaluation of Inflammatory Biomarkers in Pediatric Hematology-Oncology Patients With Bloodstream Infection

Bloodstream infection (BSI) is a serious complication in pediatric hematology-oncology patients. To evaluate the clinical significance of C-reactive protein (CRP), procalcitonin (PCT), albumin, fibrinogen, and D-dimer as potential biomarkers to differentiate among various subtypes of BSIs in pediatric patients with hematologic and oncologic diseases, we retrieved and analyzed the medical records of pediatric hematology-oncology patients diagnosed with BSI at our hospital between January 2016 and December 2017. The demographic (sex and age) and clinical (primary diseases) characteristics, and laboratory test results (white blood cell and absolute neutrophil counts, and serum CRP, PCT, albumin, fibrinogen, and D-dimer levels) were compared between nosocomial and non-nosocomial; neutropenic and non-neutropenic; and Gram-positive and Gram-negative BSI episodes. A total of 125 BSI episodes were included, including 69 (55.2%) nosocomial cases, 94 (75.2%) neutropenic cases, and 49 (39.2%) Gram-positive episodes. Of the 5 potential biomarkers evaluated (CRP, PCT, albumin, fibrinogen, and D-dimer), PCT levels were significantly lower in neutropenic episodes and Gram-positive BSIs (P=0.008 and P=0.001, respectively). At a cutoff value of 0.67 ng/mL, the diagnostic sensitivity, specificity, and positive/negative predictive values of PCT for the differentiation of Gram-positive and Gram-negative bacterial sepsis were 74.2%, 64.6%, 70.8%, and 65.2%, respectively. We concluded that PCT might potentially serve as a biomarker to differentiate between Gram-positive and Gram-negative BSIs in pediatric hematology-oncology patients.

Bacteremia in critically ill immunocompromised patients with acute hypoxic respiratory failure: A post-hoc analysis of a prospective multicenter multinational cohort

PURPOSE

The characteristics and impact of bacteremia have not been widely investigated in immunocompromised patients with acute respiratory failure (ARF).

METHODS

We performed a secondary analysis of a prospective cohort of immunocompromised patients with ARF (EFRAIM study). After exclusion of blood cultures positive for coagulase negative Staphylococci, we compared patients with (n = 236) and without (n = 1127) bacteremia.

RESULTS

The incidence of bacteremia was 17%. Bacterial pneumonia and extra-pulmonary ARDS were the main causes of ARF in bacteremic patients. Bacteremia involved gram negative rods (48%), gram positive cocci (40%) or were polymicrobial (10%). Bacteremic patients had more hematological malignancy, higher SOFA scores and increased organ support within 7 days. Bacteremia was associated with higher crude ICU mortality (40% versus 32%, p = 0.02), but neither hospital (49% versus 44%, p = 0.17) nor 90-day mortality (60% versus 56%, p = 0.25) were different from non-bacteremic patients. After propensity score matching based on baseline characteristics, the difference in ICU mortality lost statistical significance (p = 0.06), including in a sensitivity analysis restricted to patients with pneumonia.

CONCLUSIONS

We analyzed a large population of immunocompromised patients with ARF and an incidence of bacteremia of 17%. We could not demonstrate an impact of bacteremia on mortality after adjusting for baseline characteristics.

Free circulating mircoRNAs support the diagnosis of invasive aspergillosis in patients with hematologic malignancies and neutropenia

Fungal infections represent a worrisome complication in hematologic cancer patients and in the absence of disease specific symptoms, it is important to establish new biological indicators, which can be used during mould-active prophylaxis. Recently, miRNAs have appeared as candidate diagnostic and prognostic markers of several diseases. A pilot clinical study was performed to evaluate the diagnostic utility of 14 microRNAs which can be related to invasive fungal infections. Based on our data miR-142-3p, miR-142-5p, miR-26b-5p and miR-21-5p showed significant overexpression (p < 0.005) due to invasive aspergillosis in hemato-oncology patients with profound neutropenia. A tetramiR assay was designed to monitor peripheral blood specimens. Optimal cut-off was estimated by using the median value (fold change 1.1) of the log10 transformed gene expressions. The biomarker panel was evaluated on two independent sample cohorts implementing different antimicrobial prophylactic strategies. The receiver operating characteristic analysis with area under the curve proved to be 0.97. Three miRNAs (miR-142-5p, miR-142-3p, miR-16-5p) showed significant expression alterations in episodes with sepsis. In summary, the tetramiR assay proved to be a promising diagnostic adjunct with sufficient accuracy and sensitivity to trace invasive aspergillosis in hemato-oncology patients.

Microbiologically Documented Bloodstream Infection in Children With Malignancies: A Single-center Experience

BACKGROUND

Bloodstream infection (BSI) remains a considerable cause of morbidity and mortality for cancer patients. With a better understanding of it, better methods can be used. The primary objective of this study was to describe the characteristics of BSIs in our institution, and the second was to determine the possible risk factors associated with them.

MATERIALS AND METHODS

Data of cancer patients from 2009 to 2015 at our institution were included. Medical information and blood cultures were analyzed to determine the BSI rate. The χ and Fisher exact tests were used for categorical data and to determine risk factors associated with BSIs and pathogens.

RESULTS

A total of 565 (8.6%) events were diagnosed with BSIs. Although Gram-negative bacteria (52.6%) were the most commonly isolated pathogens, Gram-positive microorganisms (45.0%) were also prevalent. Oral and gastrointestinal organisms were common. Pathogens were more likely to be identified in patients with central venous catheters and in patients with prolonged neutropenia (P<0.05).

CONCLUSIONS

This study provides updated epidemiology in BSIs and helps with the prevention and management of suspected BSIs in vulnerable patients. Better anti-infection therapy could be provided to these patients based on the isolated pathogens.

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

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

Pasteurella bacteraemia: Impact of comorbidities on outcome, based on a case series and literature review

OBJECTIVES

Pasteurella bacteraemia is rare, but has been associated with a high mortality rate. The aim of this study was to estimate the impact of comorbidities on patients with Pasteurella bacteraemia.

METHODS

All cases of Pasteurella bacteraemia in adults treated in our centre between January 2008 and December 2017 were included retrospectively and compared with cases identified in a systematic review of the literature via MEDLINE covering the years 1951-2017. The epidemiological, bacteriological, and clinical data were collected, as well as the instances of death after 30 days.

RESULTS

Twenty cases of Pasteurella bacteraemia identified in our centre and 99 cases from the literature review were included. A major comorbidity was found in 80/119 (67.2%) patients. The death rate at 30 days was 31.1%. The most common comorbidities were cirrhosis, immunosuppressive therapy, and malignant diseases. Age was not associated with mortality. On multivariate analysis, the only factor associated with mortality was a major comorbidity (odds ratio 2.78, 95% confidence interval 1.01-7.70; p = 0.04).

CONCLUSIONS

This study confirms the high mortality rate and highlights the importance of the host background, independent of age, in Pasteurella bacteraemia. Clinicians should be aware of the comorbidities in cases of Pasteurella infection, due to the poor prognosis of bacteraemia.

Etiology, drug sensitivity profiles and clinical outcome of bloodstream infections: A retrospective study of 784 pediatric patients with hematological and neoplastic diseases

Bloodstream infections (BSI) represent one of the most serious complications in patients in the hematology-oncology unit. In this study, the prevalence, distribution, drug sensitivity profiles, and clinical outcome of BSI were analyzed in pediatric patients with hematological malignancies. Patients admitted to the pediatric hematology-oncology unit at Shenzhen Children's Hospital (Shenzen, China) between January 2016 and December 2017 were enrolled. Their medical records, including gender, age, primary diseases, and microbiology results of all clinical specimens, were reviewed. The incidence of BSI, microbiology characteristics, and effectiveness of antimicrobial therapy were analyzed. A total of 125 BSI cases in 108 patients (mean age, 5.5 years) were recorded, of which 69 (55.2%) were nosocomial BSI cases. The overall rate of BSI was 18.8% in the hematology-oncology unit, of which 75 (75.2%) episodes were neutropenic patients. Patients with nosocomial BSIs and the neutropenic group were older (p#.02, p#.03). HSCTs and AML were more often observed in nosocomial BSIs, while solid tumors were more found in nonnosocomial and non-neutropenic BSIs. BSIs were dominated by Gram-negative pathogens (49.6%) in the hematology-oncology unit compared with Gram-positive pathogens (39.2%). The most common pathogens were coagulase-negative Staphylococcus (24.2%) followed by Klebsiella pneumonia (15.2%), Escherichia coli (12.5%), viridans streptococci (8.2%), and Candida species (7.8%). The antibiotic therapy success rate in patients was 93.5%. Based on our center's experience, Gram-negative pathogens were commonly observed among pediatric hematology-oncology patients with BSI. Coagulase-negative Staphylococcus and K. pneumoniae predominated and antibiotic therapy was effective in these patients.

Shock and Early Death in Hematologic Patients with Febrile Neutropenia

Empirical antibiotic therapy with a beta-lactam is the standard of care in febrile neutropenia (FN) and is given to prevent early death. The addition of vancomycin is recommended in certain circumstances, but the quality of evidence is low, reflecting the lack of clinical data. In order to characterize the epidemiology of early death and shock in FN, we reviewed all episodes of FN from 2003 to 2017 at University Hospital, Federal University of Rio de Janeiro, and looked at factors associated with shock at first fever and early death (within 3 days from first fever) by univariate and multivariate analyses. Among 1,305 episodes of FN, shock occurred in 42 episodes (3.2%) and early death in 15 (1.1%). Predictors of shock were bacteremia due to Escherichia coli (odds ratio [OR], 8.47; 95% confidence interval [95% CI], 4.08 to 17.55; P < 0.001), Enterobacter sp. (OR, 7.53; 95% CI, 1.60 to 35.33; P = 0.01), and Acinetobacter sp. (OR, 6.95; 95% CI, 1.49 to 32.36; P = 0.01). Factors associated with early death were non-Hodgkin's lymphoma (OR, 3.57; 95% CI, 1.18 to 10.73; P = 0.02), pneumonia (OR, 21.36; 95% CI, 5.72 to 79.72; P < 0.001), shock (OR, 11.64: 95% CI, 2.77 to 48.86; P = 0.01), and bacteremia due to Klebsiella pneumoniae (OR, 5.91; 95% CI, 1.11 to 31.47; P = 0.03). Adequate empirical antibiotic therapy was protective (OR, 0.23; 95% CI, 0.07 to 0.81; P = 0.02). Shock or early death was not associated with Gram-positive bacteremia; catheter-related, skin, or soft tissue infection; or inadequate Gram-positive coverage. These data challenge guideline recommendations for the empirical use of vancomycin at first fever in neutropenic patients.

Differential risk of severe infection in febrile neutropenia among children with blood cancer or solid tumor

OBJECTIVE

To describe and analyze the differences between infections in children with febrile neutropenia (FN) treated for solid tumor or blood cancer.

METHODS

A prospective study included all episodes of FN in children from April 2007 to April 2016 in 2-pediatric cancer centers in France. Medical history, clinical and laboratory data available at admission and final microbiological data were collected. The proportion of FN, severe infection, categories of microorganisms and outcomes were compared between the two groups. The presumed gateway of the infection was a posteriori considered and evaluated.

RESULTS

We analyzed 1197 FN episodes (mean age: 8 years). 66% of the FN episodes occurred in children with blood cancer. Severe infections were identified in 23.4% of episodes overall. The rate of severe infection (28.4% vs. 10.4%), types of microorganisms and the need for a management in intensive care unit (2.6% vs. 0.5%) was significantly different between children with blood cancer and solid tumor. Digestive or respiratory presumed gateway of the infections was less frequent for patients with solid tumor.

CONCLUSION

Given these important microbiological and clinical differences, it may be appropriate to consider differently the risk of severe infection in these two populations and therefore the management of FN.

The incidence, risk factors and outcomes of early bloodstream infection in patients with malignant hematologic disease after unrelated cord blood transplantation: a retrospective study

BACKGROUND

Bloodstream infection (BSI) is one of the major causes of morbidity and mortality for patients undergoing hematopoietic stem cell transplantation (HSCT). The unrelated cord blood transplantation (UCBT) can provided opportunities for patients without suitable donors for bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT), while few studies have addressed BSI after UCBT. The aim of this study was to analyse the incidence and risk factors of BSI, causative organisms, microbial resistance, and its impact on the clinical outcomes and survival of patients.

METHODS

There are 336 patients, were divided into two groups depending on whether developing BSI. Demographic characteristics, laboratory data, and clinical outcome were compared between different groups. The risk factors of BSI was examined using logistic regression and the survival was examined using the Kaplan-Meier method and log-rank test.

RESULTS

Ninety-two patients (27.4%) developed early BSI with 101 pathogenic bacteria isolated, and the median day of developing initial BSI was 4.5 d. Gram-negative bacteria were the most common isolate (60, 59.4%), followed by Gram-positive bacteria (40, 39.6%) and fungi (1, 1.0%). Thirty-seven (36.6%) isolates were documented as having multiple drug resistance (MDR). Myeloid malignancies, conditioning regimens including total body irradiation (TBI), and prolonged neutropenia were identified as the independent risk factors for early BSI. The 3-year OS was 59.9% versus 69.2% in the BSI group and no-BSI group (P = 0.0574), respectively. The 3-year OS of the MDR group was significantly lower than that of the non-BSI group (51.1% versus 69.2%, p = 0.013).

CONCLUSIONS

Our data indicate that the incidence of early BSI after UCBT was high, especially in patients with myeloid disease and a conditioning regimen including TBI and prolonged neutropenia. Early BSI with MDR after UCBT had a negative impact on long-term survival.

Comparison of mono- and combination antibiotic therapy for the treatment of Pseudomonas aeruginosa bacteraemia: A cumulative meta-analysis of cohort studies

It is currently unknown whether antibiotic monotherapy or combination therapy is a more effective treatment for patients with Pseudomonas aeruginosa bacteraemia. The present study consists of a systematic review and meta-analysis of cohort studies in associated studies. The treatment options of monotherapy and combination therapy have been compared, to determine which is more effective against P. aeruginosa bacteraemia. Several electronic bibliographic databases were systematically searched and clinical studies that compared combination therapy with monotherapy for P. aeruginosa bacteraemia were identified. Dersimonian and Laird's random-effects models were used to generate summary estimates of the effects and to assess their association according to different patient characteristics and research quality standards. A total of 17 studies were selected, 3 of which were prospective while the remaining 14 were retrospective. The studies involved a total of 2,504 patients. Significant differences between combination therapy and monotherapy treatment were not found when the data were combined (odds ratio (OR)=0.81, 95% confidence interval (CI)=0.61–1.08; P=0.035). The results demonstrated strength in a number of stratification and sensitivity analyses. The variables used included study type, treatment quality score and survival rate of subgroup analysis. To conduct cumulative meta-analysis, the number of years and samples were calculated. The OR value and 95% CI were stable and demonstrated good change trend. According to the size of the sample order following accumulation, OR values and 95% CI (0.89, 0.76–1.04) exhibited a narrow range. Neither combination therapy or monotherapy exhibited significant effects on the mortality of patients with P. aeruginosa bacteraemia. Future research is required and should include large, well-designed prospective cohorts, and grouped clinical studies.

Prevalence and risk factors of Gram-negative bacilli causing blood stream infection in patients with malignancy

Objectives:

To evaluate the epidemiology, risk factors, and antibiotic resistance of Gram negative bacteria (GNB) in patients with hematologic or solid organ malignancies.

Methods:

This is a retrospective study of 61 episodes of GNB bacteremia occurring in 56 patients with malignancy admitted to the Oncology Units in King Khalid University Hospital, Riyadh. Kingdom of Saudi Arabia during the period from January 2013 to October 2015. Data were retrieved from the computerized database of the microbiology laboratory and the patient’s medical records.

Results:

Hematological malignancies accounted for 30 (54%) and solid tumors accounted for 26 (46%). The most common hematological malignancies were leukemia 23 (77%), followed by lymphoma 6 (20%). Among solid tumors, colorectal cancer 9 (34.6) and breast cancer 6 (23%) were the most common. The most predominant pathogen was Escherichia coli (E. coli) (29.5%) followed by Acinetobacter baumannii (A. baumannii) (18%). The extended-spectrum beta-lactamases producers rate of E. coli and Klebsiella pneumonia was (34.6%). Imipenem resistance among Pseudomonas aeruginosa/A. baumannii was high (52.4%). The multi-resistant organisms rate was (43.5%). Risk factors associated with the bacteremia were ICU admission (32.1%), post-surgery (23.2%), and placement of central line (21.4%). The overall 30-day mortality rate of the studied population was high (32.1%).

Conclusion:

In light of the high resistant rate among the GNB isolated from malignancy patients from our institution, careful selection of antimicrobial treatment based on antimicrobial susceptibility testing is recommended.

Bloodstream infections in acute myeloid leukemia patients treated according to the Finnish Leukemia Group AML-2003 protocol - a prospective nationwide study

BACKGROUND

Infections greatly influence the outcome of acute myeloid leukemia (AML) patients receiving intensive treatment. The aim of this study was to establish the incidence, microbial etiology, risk factors and prognosis of bloodstream infections (BSIs) in patients with AML and compare the results with the previous treatment protocol (AML-92).

METHODS

Registery data were gathered prospectively from 357 patients aged 16-65 years recruited on the AML-2003 treatment protocol between November 2003 and November 2011 during different treatment cycles.

RESULTS

Blood culture data were available on 977 treatment episodes, in which there were 503 BSIs (51%). The overall incidence rate (IR) for BSIs (per 1000 hospital days) was 16.7. Twenty patients (5.6%) died due to an infection and 16 of them (80%) had a BSI. The most commonly detected microbes (polymicrobial episodes included) in blood cultures were coagulase-negative staphylococci (CoNS, 24.7%), viridans group streptococci (VGS, 19.1%), enterococci (13.9%) and Enterobacteriacae group (25.9%). The etiology of BSIs varied greatly from treatment cycle to cycle.

CONCLUSIONS

Enterococcal BSIs have increased compared to our previous treatment protocol, and they represent significant pathogens in blood cultures. Infection-related mortality has decreased despite the increase in the IR of BSIs. Enterococci seem to be an increasingly prominent pathogen underlying BSIs in the AML patients, especially during induction therapy (20%).

Increasing Antimicrobial Resistance Monitored in Surveillance Analysis of Blood Stream Infections in Febrile Neutropenic Pediatric Oncology Patients

BACKGROUND

Continuous surveillance of pattern of blood stream infection is necessary in febrile neutropenia (FN)especially with the recent escalating trend in the management of pediatric cancer patients towards intensified regimens and with the increase in infections caused by resistant organisms limiting the choice of antibiotics.

AIM

To monitor change in pattern of blood stream infections (BSI) in FN pediatric cancer patients.

MATERIALS AND METHODS

Surveillance of FN episodes with positive BSI was prospectively monitored and compared to a previous surveillance in the same pediatric oncology unit.

RESULTS

A total of 232 BSI positive episodes were documented in 192 patients during a 6 months period. The results of recent surveillance analysis showed an increase in intensified regimens of chemotherapy, antimicrobial resistance, fungal infections, and prolonged duration of episodes when compared to previous surveillance, with p value sof <0.001, 0.005, 0.021, and <0.001, respectively. There was an apparent decrease in the crude mortality but this was not statistically significant, to 6% in 2011 from 10 % in 2006.

CONCLUSIONS

The pattern of BSI at our institution is still inclining towards gram positive organisms but is showing a shift towards more antibiotic resistance and fungal infections.

[Pathogens and clinical characteristics of bacterial infection in hematology department between 2010 and 2014]

OBJECTIVE

To analyze the characteristics of distribution and drug resistance of bacterial infection in several different parts of hematology department inpatients of Anhui Provincial Hospital from January 2010 to December 2014, including patients who had received hematopoietic stem cell transplantation (HSCT).

METHODS

Anti-microbial susceptibility test was done by Kirby-Bauer method and automated systems and the data were analysed by WHONET 5.6 software.

RESULTS

A total of 3 312 copies of inspection samples were analyzed, including 2 716 (82%) blood samples and other 596 specimens (18%). 634 bacterial strains were isolated from 3 312 samples (19.14%) including 488 samples (76.97%) from blood culture. 427 (67.35%) bacterial strains were gram-negative, and the other 207 (32.65%) were gram-positive. Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were most common gram-negative bacterial and the resistant rates to imipenem were 0.8%, 11.8% and 3.3%, respectively. Detection rates of Extended-spectrum beta-lactamases in Escherichia coli and Klebsiella pneumoniae were 83.9% and 75.0%, respectively. At the same time, Coagulase negative Staphylococcus, Streptococcus and Enterococcus were most common kinds of gram-positive bacteria. Methicillin-resistant coagulase negative staphylococcus accounted for 65.9% antibiotic resistance. No vancomycin and/or linezolid and/or tigecycline resistant strains of Staphylococcus spp. and Enterococcus spp. were found in those patients.

CONCLUSION

Patients with hematology diseases had a higher risk of bacterial infections, mainly caused by Gram-negative bacteria. There are different distributions of bacterial in different wards.

Prospective Evaluation of Infection Episodes in Cancer Patients in a Tertiary Care Academic Center: Microbiological Features and Risk Factors for Mortality

OBJECTIVE

We aimed to determine the frequency, type, and etiology of infections and the risk factors for infections and mortality in hospitalized cancer patients.

MATERIALS AND METHODS

We prospectively enrolled adult cancer patients hospitalized in the internal medicine wards of a tertiary care academic center between January and August 2004. Patients were followed during their hospitalization periods for neutropenia, infections, culture results, and mortality.

RESULTS

We followed 473 cancer patients with 818 hospitalization episodes and 384 infection episodes in total. Seventy-nine percent of the infections were nosocomial, and febrile neutropenia (FN) was observed in 196 (51%) of the infection episodes. Bacteremia was found in 29% of FN episodes and in 8% of nonneutropenic patients. Gram-positive bacteria were the leading cause of bacteremia in both neutropenic and nonneutropenic cases (70% and 58%, respectively). Presence of an indwelling central catheter increased bacteremia risk by 3-fold. The overall mortality rate was 17%, whereas 34% of the patients with bloodstream infections died. Presence of bacteremia and advanced disease stage increased overall mortality by 6.1-fold and 3.7-fold, respectively.

CONCLUSION

Nearly half of the cancer patients developed an infection during their hospital stays, with gram-positive bacteria being the predominant etiologic microorganisms. This demonstrates the changing trends in infections considering that, until 2004, gram-negative bacteria were the most predominant microorganisms among cancer patients in our institute.

Bloodstream infections in neutropenic cancer patients: A practical update

Bloodstream infections (BSI) are among the most frequent complications in neutropenic cancer patients and, if caused by Gram-negative rods, are associated with high mortality. Thus, fever during neutropenia warrants prompt empirical antibiotic therapy which should be active against the most frequent Gram-negatives. In the last decade, there has been a worldwide increase in multidrug resistant (MDR) strains. In these cases, the traditional choices such as oral therapy, ceftazidime, cefepime, piperacillin-tazobactam, or even carbapenems, might be ineffective. Therefore novel de-escalation approach has been proposed for patients who are at high risk for infections due to MDR bacteria. It consists of starting antibiotics which cover the most probable resistant strain but it is narrowed down after 72 hours if no MDR pathogen is isolated. With increasing bacterial resistance, the benefit of fluoroquinolone prophylaxis during prolonged neutropenia remains to be confirmed. Antibiotic stewardship and infection control programs are mandatory in every cancer center.

Association of proton pump inhibitors with the occurrence of gut-derived bacteraemia in patients with haematological malignancy after chemotherapy

BACKGROUND

Gut-derived bacteraemia is a major complication in patients with haematological malignancy after chemotherapy.

OBJECTIVE

Our study aimed to investigate the role of proton pump inhibitors (PPIs) in the occurrence of gut-derived bacteraemia.

METHODS

We compared data from 92 hospitalized haematological malignancy patients after chemotherapy with gut-derived bacteraemia, collected from January 2009 to July 2015, with those of 92 contemporaneous, hospitalized haematological malignancy patients without bacteraemia. We evaluated PPIs use and analysed the effects of covariates.

RESULTS

Patients with gut-derived bacteraemia had a significantly higher incidence of PPIs use (69.6%) than that of controls (47.8%). Of the patients with gut-derived bacteraemia, only 44.6% had a documented indication for PPIs therapy. The antibacterial prophylaxis rate was 38.0% in the bacteraemia group and 58.7% in the non-antibacterial group. Based on multivariable logistic regression analysis, only PPIs use (P = 0.00, odds ratio (OR) = 0.546) was found to be associated with the risk of bacteraemia whereas antibacterial prophylaxis (P = 0.00, OR = 0.652) was protective. There were no significant differences in demographics, malignancy status, length of neutropenia, complications, or steroid use between the gut-derived bacteraemia and control group.

CONCLUSIONS

This study suggests a potential association between PPIs use and development of gut-derived bacteraemia in haematological malignancy patients after chemotherapy.

Bloodstream infections in patients with solid tumors

Little information is currently available regarding bloodstream infection (BSI) in patients with solid tumors who, for a variety of reasons, are particularly predisposed to develop this condition. In this review we focus on the incidence, epidemiology, clinical features, etiology, antimicrobial resistance, and outcomes of BSI of adult cancer patients with solid tumors. Most episodes of BSI occur in non-neutropenic patients, in whom the site of primary or metastatic tumor often serves as the portal of entry. The urinary tract and the abdomen are the most frequent sources of infection, and cholangitis is the most common recurrent source of BSI. Gram-negative bacilli are becoming the leading cause of BSI in patients with solid tumors, and the rate of multidrug resistance is increasingly being recognized. The case-fatality rate in patients with solid tumors and BSI is high, especially among those with comorbidities, advanced neoplasms, corticosteroid therapy, and shock at presentation.

The challenge of antibiotic resistance in haematology patients

Bacterial infections were once a major obstacle to the treatment of acute leukaemia. Improvement in management strategies, including the use of broad-spectrum antibacterial drugs targeting Gram-negative bacteria, has reduced the mortality in neutropenic patients developing blood stream infections and other severe infections. In many countries these achievements are threatened by development of multi-resistant bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. This review addresses the epidemiology, clinical importance and possible management of these multi-resistant organisms.

Factors influencing mortality in neutropenic patients with haematologic malignancies or solid tumours with bloodstream infection

The purpose of this study was to identify factors influencing mortality in neutropenic patients with haematologic malignancies or solid tumours with bloodstream infection (BSI). All episodes of BSI occurring in adult neutropenic patients with haematologic malignancies or solid tumours were prospectively recorded from January 2006 to December 2013. We analysed the factors influencing mortality in both groups of patients. We documented 602 consecutive episodes of BSI; 510 occurred in patients with haematologic malignancies and 92 in patients with solid tumours. The overall case-fatality rates were 12% and 36%, respectively. Independent risk factors associated with a higher case-fatality rate in patients with haematologic malignancies were: intensive care unit admission (odds ratio (OR), 15.2; 95% confidence interval (CI), 5.4-42.7), advanced neoplasm (OR, 8.7; 95% CI, 2.9-25.7), corticosteroid therapy (OR, 7.0; 95% CI, 3-16.4), multidrug-resistant Gram-negative BSI (OR, 3.8; 95% CI, 1.2-11.8) and a Multinational Association for Supportive Care in Cancer risk score of <21 (OR, 3.1; 95% CI, 1.3-7.4). By contrast, coagulase-negative staphylococci BSI (OR, 0.04; 95% CI, 0.004-0.5) and empirical antibiotic combination therapy (OR, 0.1; 95% CI, 0.05-0.3) were found to be protective. Independent risk factors for overall case-fatality rate in patients with solid tumours were: shock at presentation (OR, 14.3; 95% CI, 3.2-63.8), corticosteroid therapy (OR, 10; 95% CI, 2.3-44) and advanced neoplasm (OR, 7.8; 95% CI, 1.4-41.4). Prognostic factors identified in this study may help to detect those patients at higher risk of death in each group. Medical intervention addressing some of these factors might improve the outcome of BSI in neutropenic patients with haematologic malignancies or solid tumours.

Prevention of transmission of multidrug-resistant organisms during catheter exchange using antimicrobial catheters

Exchanging a central venous catheter (CVC) over a guide wire for a fresh uncoated CVC in the presence of bacteremia can result in cross-infection of the newly exchanged CVC. A recent retrospective clinical study showed that exchanging a catheter over a guide wire in the presence of bacteremia using an antimicrobial minocycline-rifampin (M/R) catheter may improve outcomes. To expand on this, we developed an in vitro cross-contamination model of exchange to evaluate the efficacy of different antimicrobial CVCs in preventing cross-contamination of multidrug-resistant organisms during exchange. Uncoated CVCs were allowed to form biofilm by methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. After 24 h, the biofilm-colonized CVCs were placed in a glass tube containing bovine calf serum plus Mueller-Hinton broth, and each catheter was exchanged over a guide wire for a fresh uncoated or an M/R-, chlorhexidine-silver sulfadiazine (CHX/SS)-, or chlorhexidine-M/R (CHX-M/R)-coated CVC. Cross-contamination of exchanged catheters was enumerated by sonication and quantitative plating methods. The exchange of M/R CVCs completely prevented cross-contamination by MRSA biofilms compared to control exchanged CVCs (P<0.0001). Exchange with CHX/SS CVCs reduced but did not completely prevent cross-contamination by MRSA (P=0.005). Exchange with CHX-M/R CVCs completely prevented cross-contamination by MRSA, P. aeruginosa, and C. albicans biofilms (P<0.0001). Furthermore, CHX-M/R CVCs were superior to M/R CVCs against P. aeruginosa and C. albicans (P=0.003) and were superior to CHX/SS CVCs against MRSA and P. aeruginosa (P=0.01). In conclusion, exchange with the novel CHX-M/R CVC was the only exchange effective in completely and concurrently preventing cross-contamination from bacteria and Candida.

Risk factors for mortality in patients with Pseudomonas aeruginosa bacteremia; retrospective study of impact of combination antimicrobial therapy

BACKGROUND

Whether the combination of antimicrobial therapy is a factor in mortality in Pseudomonas aeruginosa bacteremia remains to be elucidated. This study investigated the risk factors for mortality in P. aeruginosa bacteremia patients and the influence of adequate antimicrobial therapy and combination therapy on clinical outcomes.

METHODS

This retrospective study analyzed data of 234 patients with P. aeruginosa bacteremia at a 1,200-bed tertiary teaching university hospital in South Korea between January 2010 and December 2012. Factors associated with mortality were determined. Mortality was compared in patients with adequate empirical and targeted combination therapy, and monotherapy, and inappropriate therapy.

RESULTS

A total of 141 (60.3%) patients were given appropriate empirical antibiotic treatment (combination therapy in 38 and monotherapy in 103). Among 183 patients (78.2%) who finally received appropriate targeted treatment, 42 had combination therapy and 141 had monotherapy. The percentage of patients receiving empirical combination therapy was slightly, but not significantly higher, in the survivor group than in the nonsurvivor group (17.0% [31/182] vs. 13.5% [7/52], p = 0.74). A similar tendency was demonstrated for targeted combination therapy (19.8% [36/182] vs. 11.5% [6/52], respectively; p = 0.31). However, in a subgroup analysis of data from patients (n = 54) with an absolute neutrophil count less than 500/mm3, the patients who had appropriate empirical or targeted combination therapy showed better outcomes than those who underwent monotherapy or inappropriate therapy (p < 0.05). Mechanical ventilation (odds ratio [OR], 6.93; 95% confidence interval [CI], 2.64-18.11; p = 0.0001), the use of a central venous catheter (OR, 2.95; 95% CI, 1.35-6.43; p = 0.007), a high Acute Physiology and Chronic Health Evaluation II score (OR, 4.65; 95% CI, 1.95-11.04; p = 0.0001), and presence of septic shock (OR, 2.91; 95% CI, 1.33-6.38; p = 0.007) were independent risk factors for 14-day mortality.

CONCLUSIONS

Disease severity was a critical factor for mortality in our patients with P. aeruginosa bacteremia. Overall, combination therapy had no significant effect on 14-day mortality compared with monotherapy. However, appropriate combination therapy showed a favorable effect on survival in patients with febrile neutropenia.

Prognostic factors for mortality with fungal blood stream infections in patients with hematological and non-hematological malignancies

Background:

This single center retrospective analysis was undertaken to identify the incidence, clinical impact, and prognostic factors for mortality associated with fungal blood stream infections (BSI) in cancer patients.

Materials and Methods:

One hundred and twenty four patients had 169 episodes of fungal BSI. Incidence has not changed over a 10 year period but non albicans candida species are the predominant fungal isolates. Mortality with fungal BSI was significantly higher than that with other microbial agents. Risk of mortality was associated with renal dysfunction and Candida albicans as the isolate. Type of chemotherapy, patient characteristics, and neutrophil count did not influence the mortality following fungal BSI.

Conclusion:

Fungal BSI is rare and the incidence has not changed in this hospital. Mortality associated with fungal BSI is high. Risk score at the time of developing fungal BSI has prognostic potential to identify patients with higher risk of mortality associated with fungal BSI.