Profiling of bacterial bloodstream infections in hematological and oncological patients based on a comparative survival analysis

Epidemiology and outcomes of Candida spp. bloodstream infections in cancer patients: a comparative retrospective study from a German tertiary cancer center

BACKGROUND

Bloodstream infections (BSI) due to Candida spp. significantly contribute to morbidity and mortality among cancer patients. Understanding their clinical course, risk factors, and outcomes compared to bacterial BSI is essential.

AIM

We aim to elucidate the epidemiology and risk factors associated with Candida BSI compared to bacterial BSI in cancer patients.

METHODS

We analyzed epidemiological data of Candida BSI versus bacterial BSI among cancer patients, primarily with hematological malignancies. Blood cultures were obtained upon clinical suspicion, with species identification by VITEK 2 and MALDI-TOF. Susceptibility testing utilized VITEK 2 or antibiotic gradient tests.

RESULTS

Candida BSI was associated with higher 30-day mortality compared to bacterial BSI (Hazard ratio (HR) 4.5, 95% CI 2.5-8.1, p < 0.001) occurring predominantly in patients with relapsed/refractory disease. Univariate analysis identified risk factors for Candida BSI: hypoalbuminemia (Odds ratio (OR) 9.13, 95% CI 2.7-57, p = 0.003), prior ICU/MC stay (OR 3.91, 95% CI 1.38-9.65, p = 0.005), palliative treatment (OR 3.42, 95% CI 1.52-7.4, p = 0.002), parenteral nutrition (OR 2.44, 95% CI 0.9-5.5, p = 0.039) and prior allogeneic HSCT (OR 2.28, 95% CI 0.92-5.13, p = 0.056). Risk factors identified by multivariate analysis were palliative therapy (OR 5.23, 95% CI 3.14-8.71, p = 0.001), hypoalbuminemia (OR 9.02, 95% CI 4.23-19.2, p = 0.004), and prior ICU/IMC stay (OR 4, 95% CI 2.31-6.92, p = 0.011). In patients with confirmed Candida BSI, delayed initiation of antifungal was associated with worse outcomes.

CONCLUSION

Compared to bacterial BSI events, Candida BSI are associated with significantly higher 30-day mortality, primarily affecting heavily pretreated patients with relapsed or refractory disease.

Empiric antibiotic therapy resistance and mortality in emergency department patients with bloodstream infection: a retrospective cohort study

BACKGROUND

Timely management of sepsis in the emergency department, including the use of appropriate antimicrobials, is crucial for improving patient outcomes. Inadequate empiric antimicrobial treatment is associated with potential changes in patient outcomes. We aimed to pinpoint risk factors, characterize antibiotic resistance trends, and investigate the association between antibiotic resistance and mortality among patients with bacteremia admitted to the emergency department.

METHODS

We conducted a retrospective analysis of emergency department patients admitted between 15/06/2016 and 30/09/2022. Patients with a positive blood culture receiving emergency department-initiated antibiotic therapy were included. Antibiotic administration, resistance, and survival data were collected. Descriptive statistics, survival analysis, and Cox proportional hazards models were performed.

RESULTS

Of 157,884 emergency department visits, 1,136 patients had a positive blood culture and received antibiotic therapy initiated in the emergency department. Resistance against empiric antibiotics was 14.5%. The overall 30-day and one-year mortality was 38.6% and 61.8%, respectively. In adjusted Cox models, patients with Escherichia coli or Staphylococcus aureus infection had 36% lower and 44% higher risk of death, respectively. Although resistance to emergency department-administered antibiotic therapy was not associated with overall mortality, one-year mortality of patients with Escherichia coli bacteremia was higher in those with antibiotic resistance (69.0% vs. 49.4%, p = 0.011); these patients had a 1.5-fold increased risk of death in an adjusted Cox model.

CONCLUSION

The mortality of patients with bloodstream infection is high. The association of mortality with empiric emergency department-initiated antibiotic adequacy is pathogen-dependent.

[Chinese expert consensus on diagnosis, treatment and management of critically ill patients in hematology intensive care unit (2025)]

Recently, survival rates for patients with hematological malignancies (HMs) have improved, but severe complications have also risen accordingly, and can escalate quickly. Establishing a hematology intensive care unit (HCU) is crucial for early detection and centralized monitoring of critically ill hematological patients, as well as the enhancement of diagnosis, treatment and prognosis and minimizing medical disputes. Based on the guidelines of intensive care unit and hematology department, combined with clinical operation experience of domestic HCU, this consensus is participated by several leading hematology centers in China. It outlines the necessity, configuration, admission standards, management, treatment principles, and strategies of HCU. An expert agreement on managing critically ill HCU patients was achieved. It is suggested that the blood centers with eligible critieria should actively establish HCU, aiming to further lowering the mortality rate of critically ill hematology patients.

Risk factors and outcome of Pseudomonas aeruginosa bloodstream infections (PABSI) in hematological patients: a single center retrospective cohort study

PURPOSE

Bloodstream infections caused by Pseudomonas aeruginosa (PABSI) in hematological patients are associated with high morbidity and mortality. We investigated the epidemiology, risk factors, and outcomes of PABSI at our center.

METHODS

All adult hematological patients with PABSI between January 2013 and July 2023 were included. Demographic and clinical characteristics, antimicrobial susceptibilities, antibiotic therapy, fluoroquinolone-prophylaxis, source of infection, and 30-day outcome were recorded. Descriptive statistics, tests for difference, and logistic regression models were performed.

RESULTS

Fifty patients with PABSI were identified with a median age of 58.5 years (range 24-78). 37 patients (74%) had severe neutropenia, 20 (40%) received allogeneic HSCT, and 29 (58%) had acute leukemia. A total of 34 (68%) had received timely appropriate anti-pseudomonal antibiotic therapy. The most common presumed cause of PABSI was mucositis (n = 16, 32%), followed by pneumonia (8, 16%) and skin and soft tissue infections (n = 6, 12%). Empirical combination therapy was used in 16 (32%) patients, while targeted combination therapies were used in 27 (54%) patients. P. aeruginosa detection led to treatment change in 31 (62%) cases. The overall 30-day survival rate was 78% (n = 39). Carbapenem-resistance occurred in 34% (n = 17), and multidrug-resistance (MDR) in 20% (n = 10). Prior antibiotic exposure was associated with resistance. Appropriate antibiotic therapy was associated with survival, whereas antibiotic resistance and organ infection were associated with a fatal outcome.

CONCLUSION

Prior antibiotic exposure in hematological patients is associated with resistance in PABSI, which is a major risk factor for a fatal outcome. Antibiotic stewardship efforts should be intensified and fluoroquinolone prophylaxis needs to be reconsidered.

Impact of multidrug resistance on outcomes in hematologic cancer patients with bacterial bloodstream infections

Despite the improved outcomes in patients with hematological malignancies, infections caused by multidrug-resistant organisms (MDROs) pose a new threat to these patients. We retrospectively reviewed the patients with hematological cancer and bacterial bloodstream infections (BSIs) at a tertiary hospital between 2003 and 2022 to assess the impact of MDROs on outcomes. Among 328 BSIs, 81 (24.7%) were caused by MDROs. MDRO rates increased from 10.3% (2003-2007) to 39.7% (2018-2022) (P < 0.001). The 30-day mortality rate was 25.0%, which was significantly higher in MDRO-infected patients than in non-MDRO-infected patients (48.1 vs. 17.4%; P < 0.001). The observed trend was more pronounced in patients with newly diagnosed diseases and relapsed/refractory disease but less prominent in patients in complete remission. Among MDROs, carbapenem-resistant Gram-negative bacteria exhibited the highest mortality, followed by vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and extended-spectrum β-lactamase-producing Enterobacteriaceae. Multivariate analysis identified independent risk factors for 30-day mortality as age ≥ 65 years, newly diagnosed disease, relapsed/refractory disease, MDROs, polymicrobial infection, CRP ≥ 20 mg/L, and inappropriate initial antibiotic therapy. In conclusion, MDROs contribute to adverse outcomes in patients with hematological cancer and bacterial BSIs, with effects varying based on the underlying disease status and causative pathogens. Appropriate initial antibiotic therapy may improve patient outcomes.

Hospital-acquired bloodstream infections in patients with cancer: current knowledge and future directions

Patients with cancer experience higher rates of preventable harm from hospital-acquired bloodstream infections (haBSIs) and central-line-associated bloodstream infections (CLABSIs) compared with the general hospital population. The prevention of haBSIs and CLABSIs in patients with cancer is an urgent priority, and requires standardized surveillance and reporting efforts. The application of haBSI and CLABSI definitions, classification systems and surveillance strategies for patients with cancer is complex, and there is wide variation in clinical practice. Existing systems were not designed explicitly for patients with cancer, and have different strengths and weaknesses in the cancer setting. For these reasons, epidemiological estimates of haBSIs and CLABSIs in patients with cancer also require careful interpretation. This complexity can be a barrier to identifying appropriate targets for intervention and reducing preventable harm. This review provides an overview of key concepts and challenges in haBSI surveillance and prevention specific to patients with cancer. In addition, this review summarizes the strengths and weaknesses of commonly used surveillance definitions and denominators in the setting of cancer care; existing surveillance practice; epidemiology of haBSIs and CLABSIs; prevention strategies; and current knowledge gaps. A global collaborative effort to harmonize the surveillance of hospital-acquired infections in patients with cancer would be invaluable to improve the accuracy and utility of existing data, advance efforts to prevent hospital-acquired infections, and improve patient safety.

Bloodstream Infections in Pediatric Oncology Patients: Bacterial Pathogen Distribution and Antimicrobial Susceptibility at the University Hospital Centre Zagreb, Croatia-A 5-Year Analysis

The epidemiology of bacterial pathogens causing bloodstream infections (BSIs) in pediatric hematology/oncology patients is changing and resistance to antimicrobial agents is globally spread. We retrospectively assessed demographic, clinical, and microbiologic data of BSIs during a 5-year period at a pediatric hematology/oncology unit from January 1, 2017, to December 31, 2021, at the University Hospital Centre Zagreb, Zagreb, Croatia. In 66 pediatric patients with malignancies, 93 BSI episodes were registered and 97 bacterial isolates were cultured. The Gram-positive versus Gram-negative ratio was 67 (69.1%) versus 30 (30.9%). Coagulase-negative staphylococci (48; 49.6%) were the most frequent isolates, followed by Enterobacterales (17; 17.5%) and Staphylococcus aureus (6; 6.2%). Multidrug resistance isolates included extended spectrum β-lactamase producers (n=3). Resistance rates to piperacillin/tazobactam, cefepime, and meropenem in Gram-negative isolates were 15.4%, 14.3%, and 0.0%, respectively. Gram-positive bacteria are the most common cause of BSI in our patients. Resistance rates to piperacillin/tazobactam and cefepime in Gram-negative isolates make meropenem a better choice for empirical antimicrobial treatment. As national and hospital data may differ, the surveillance of pathogen distribution and antimicrobial susceptibility in pediatric hematology/oncology wards is necessary to adjust empirical treatment accordingly.

An Emergent Change in Epidemiologic and Microbiological Characteristics of Bloodstream Infections in Adults With Febrile Neutropenia Resulting From Chemotherapy for Acute Leukemia and Lymphoma at Reference Centers in Chile, Ecuador, and Peru

Background

Febrile neutropenia is a life-threatening condition commonly observed in patients with hematologic malignancies. The aim of this article is to provide updated knowledge about bloodstream infections in febrile neutropenia episodes within the Andean region of Latin America.

Method

This retrospective study was based in 6 hospitals in Chile, Ecuador, and Peru and included adult patients with acute leukemia or lymphoma and febrile neutropenia between January 2019 and December 2020.

Results

Of the 416 febrile neutropenia episodes, 38.7% had a bloodstream infection, 86% of which were caused by gram-negative rods, with Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa being the most frequently identified bacteria. K pneumoniae isolates were more frequently resistant than E coli to cefotaxime (65% vs 39.6%), piperacillin-tazobactam (56.7% vs 27.1%), and imipenem (35% vs 2.1%) and were more frequently multidrug resistant (61.7% vs 12.5%). Among P aeruginosa, 26.7% were resistant to ceftazidime, piperacillin-tazobactam, and imipenem, and 23.3% were multidrug resistant. Overall 30-day mortality was 19.8%, being higher with vs without a bloodstream infection (26.7% vs 15.3%, P = .005). Fever duration was also significantly longer, as well as periods of neutropenia and length of hospital stay for patients with bloodstream infection. Additionally, the 30-day mortality rate was higher for episodes with inappropriate vs appropriate empirical antibiotic therapy (41.2% vs 26.6%, P = .139).

Conclusions

Considering the high rates of bacteria-resistant infection and 30-day mortality, it is imperative to establish strategies that reduce the frequency of bloodstream infections, increasing early identification of patients at higher risks of multidrug bacteria resistance, and updating existing empirical antibiotic recommendations.

Changing epidemiology, microbiology and mortality of bloodstream infections in patients with haematological malignancies before and during SARS-CoV-2 pandemic: a retrospective cohort study

OBJECTIVE

This study was to explore the changes in bacterial bloodstream infection (BSI) in patients with haematological malignancies (HMs) before and during SARS-CoV-2 pandemic.

DESIGN

Retrospective cohort study between 2018 and 2021.

SETTING

The largest haematological centre in southern China.

RESULTS

A total of 599 episodes of BSI occurring in 22 717 inpatients from January 2018 to December 2021 were analysed. The frequencies of the total, Gram-negative and Gram-positive BSI before and during the pandemic were 2.90% versus 2.35% (p=0.011), 2.49% versus 1.77% (p<0.001) and 0.27% versus 0.44% (p=0.027), respectively. The main isolates from Gram-negative or Gram-positive BSI and susceptibility profiles also changed. The 30-day mortality caused by BSI was lower during the pandemic (21.1% vs 14.3%, p=0.043). Multivariate analysis revealed that disease status, pulmonary infection and shock were independent predictors of 30-day mortality.

CONCLUSION

Our data showed that the incidence of total and Gram-negative organisms BSI decreased, but Gram-positive BSI incidence increased in patients with HMs during the pandemic along with the changes of main isolates and susceptibility profiles. Although the 30-day mortality due to BSI was lower during the pandemic, the new infection prevention strategy should be considered for any future pandemics.

Antimicrobial Stewardship on Patients with Neutropenia: A Narrative Review Commissioned by Microorganisms

The emergence of antibiotic resistance poses a global health threat. High-risk patients such as those with neutropenia are particularly vulnerable to opportunistic infections, sepsis, and multidrug-resistant infections, and clinical outcomes remain the primary concern. Antimicrobial stewardship (AMS) programs should mainly focus on optimizing antibiotic use, decreasing adverse effects, and improving patient outcomes. There is a limited number of published studies assessing the impact of AMS programs on patients with neutropenia, where early appropriate antibiotic choice can be the difference between life and death. This narrative review updates the current advances in strategies of AMS for bacterial infections among high-risk patients with neutropenia. Diagnosis, drug, dose, duration, and de-escalation (5D) are the core variables among AMS strategies. Altered volumes of distribution can make standard dose regimens inadequate, and developing skills towards a personalized approach represents a major advance in therapy. Intensivists should partner antibiotic stewardship programs to improve patient care. Assembling multidisciplinary teams with trained and dedicated professionals for AMS is a priority.

Prevalence of bloodstream infection pathogens in hemato-oncological patients and predictors of carbapenem-resistant gram-negative bacterial infections during febrile neutropenia

BACKGROUND

Carbapenem-Resistant Gram-Negative (CRGN) Bloodstream Infections (BSI) represent a therapeutic challenge, especially in the context of Febrile Neutropenia (FN) in cancer patients.

METHODS

We characterized pathogens causing BSI in patients aged ≥18 years who had undergone systemic chemotherapy for solid or hematological cancers between 2012 and 2021 in Porto Alegre, Brazil. Predictors of CRGN were evaluated through a case-control analysis. Each case was matched to two controls from whom CRGN were not isolated and had the same sex and year of inclusion in the study.

RESULTS

From 6094 blood cultures evaluated, 1512 (24.8%) showed positive results. Gram-negative bacteria accounted for 537 (35.5%) of the isolated bacteria, of which 93 (17.3%) were carbapenem-resistant. From 105 patients included in the case-control analysis, all cases had baseline hematological malignancies (60% acute myeloid leukemia). Variables related to CRGN BSI in Cox regression analysis were the first chemotherapy session (p<0.01), chemotherapy performed in the hospital setting (p = 0.03), intensive care unit admission (p<0.01), and CRGN isolation in the previous year (p<0.01). Patients with CRGN BSI received 75% less empirical active antibiotics and had 27.2% higher 30-day mortality rates than controls.

CONCLUSIONS

A CRGN risk-guided approach should be considered for empirical antibiotic therapy in patients with FN.

[Management of infection in immunocompromised patients]

The number of immunosuppressed patients continues to increase worldwide. The main reasons are the demographic development and improved long-term survival, also for patients under immunosuppression. A major cause of hospitalization and mortality among these patients are infections. Their management, including prevention and adequate treatment, plays a crucial role in survival and quality of life, but also with regard to economic factors.Infection management in immunocompromised patients faces new challenges today. Not only the increasing number, but also new groups of patients at risk and an increasingly aging and comorbid population pose problems for the treating physicians. While cancer medicine is no longer determined solely by radiotherapy and chemotherapy, new targeted substances are playing an increasingly important role. In addition, new targeted substances complicate adequate infection prophylaxis due to potential interactions. The worldwide increase in antibiotic-resistant pathogens complicates treatment of bacterial infections, which is associated with increased mortality, especially in the immunocompromised patient population. Further, the disruption of the microbiome shows negative antibiotic-associated effects. Hence the reasonable use of anti-infectives in prophylaxis and therapy is of great importance.There are many recommendations and guidelines for clinicians regarding the management of infections in immunocompromised patients. Overlaps of infectiology, hygiene as well as hematology and oncology sometimes lead to different recommendations. This article provides an overview of the currently existing evidence and guidelines for infection management in immunosuppressed patients.