Incidence, risk factors, and outcome of blood stream infections during the first 100 days post-pediatric allogeneic and autologous hematopoietic stem cell transplantations

Epidemiology, Microbiology, and Risk Factors of Bacterial Bloodstream Infections in Patients After Allogeneic Hematopoietic Stem Cell Transplantation

Purpose

To investigate the clinical characteristics, etiology, and risk factors of bacterial bloodstream infection (BSI) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. This study also aimed to provide a clinical basis for early identification of high-risk patients and optimization of empirical antimicrobial treatment.

Patients and Methods

This is a retrospective study of clinical data during agranulocytosis from 331 patients with hematological malignancies who underwent allo-HSCT at our institute between January 2016 and December 2022. The incidence, distribution and drug resistance patterns, and the risk factors of BSI were analyzed.

Results

Among the 331 HSCT patients, 250 had febrile neutropenia and 45 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 18% (45/250). A total of 48 pathogens were isolated during BSI episodes, gram-negative bacteria (GNB) accounted for 70.8% (34/48), gram-positive bacteria (GPB) for 29.2% (14/48). Multivariate analysis revealed that ≥grade 2 acute graft-versus-host disease (aGVHD) and previous BSI within 6 months before HSCT were independently associated with an increased occurrence of BSI. Coagulase-negative staphylococci (CoNS) and Escherichia coli were the most commonly isolated GPB and GNB, respectively. A total of 32 GNB were tested for drug susceptibility, the detection rate of carbapenem-resistant Enterobacteriaceae (CRE) was 12.5% (4/32), and extended-spectrum β-lactamase (ESBL) accounted for 56.3% (18/32).

Conclusion

BSIs are still a common and severe complication after allo-HSCT. In our center, BSIs in allo-HSCT patients are dominated by gram-negative bacteria and the resistance rate to carbapenem drugs is high. Risk factors for BSI during agranulocytosis were previous BSI within 6 months before HSCT and ≥grade 2 aGVHD.

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.

CTX-M, TEM, and SHV Genes in Escherichia coli, Klebsiella pneumoniae, and Enterobacter spp Isolated from Hematologic Cancer Patients with Bacteremia in Uganda

Purpose

We determined the phenotypic resistance to third-generation cephalosporins, phenotypic extended spectrum beta-lactamase (ESBL) prevalence, and genotypic prevalence of ESBL-encoding genes blaCTX-M, blaTEM, and blaSHV in Enterobacteriaceae isolated from hematologic cancer patients with febrile neutropenia and bacteremia at the Uganda Cancer Institute (UCI).

Patients and Methods

Blood cultures from hematologic cancer patients with febrile neutropenia were processed in BACTEC 9120. E. coli, K. pneumoniae, and Enterobacter spp. isolates were identified using conventional biochemical methods. Antimicrobial susceptibility tests, phenotypic ESBL characterization, and genotypic characterization of the ESBL-encoding genes blaCTX-M, blaTEM, and blaSHV were determined for pure isolates of E. coli, K. pneumoniae, and Enterobacter spp.

Results

Two hundred and two patients were included in the study. Median age of patients was 19 years (IQR: 10-30 years). Majority (N=119, 59%) were male patients. Sixty (30%) of the participants had at least one febrile episode due to Enterobacteriaceae. Eighty-three organisms were isolated with E. coli being predominant (45, 54%). Seventy-nine (95%) Enterobacteriaceae were multidrug resistant. The ESBL phenotype was detected in 54/73 (74%) of Enterobacteriaceae that were resistant to third-generation cephalosporins. A higher proportion of Enterobacteriaceae with ESBL-positive phenotype were resistant to piperacillin-tazobactam (p=0.024), gentamicin (p=0.000), ciprofloxacin (p=0.000), and cotrimoxazole (p=0.000) compared to Enterobacteriaceae, which were sensitive to third-generation cephalosporins. The organisms were more susceptible to carbapenems and chloramphenicol than resistant. ESBL-encoding genes (blaCTX-M, blaTEM, and blaSHV) were detected in 55 (75%) of the 73 Enterobacteriaceae that were resistant to third-generation cephalosporins. BlaCTX-M, was the most common ESBL-encoding gene identified with 50 (91%).

Conclusion

ESBL-producing Enterobacteriaceae are a predominant cause of bacteremia in hematologic cancer patients at UCI. The most common ESBL-encoding gene identified in the ESBL-PE was blaCTX-M. Resistance to imipenem and meropenem was low.

Epidemiology of bloodstream infections and the impact of antimicrobial resistance in pediatric hematopoietic cell transplant

Bloodstream infections (BSI) pose a substantial threat to the well-being and survival of patients undergoing hematopoietic stem cell transplantation (HSCT). Risk factors for these infections vary across the different post-HSCT phases. In the pre-engraftment period, patients are particularly susceptible to infection due to prolonged neutropenia, mucosal damage, and extensive use of central venous line (CVL). In the post-engraftment phase, the emergence of graft versus host diseases further compounds the risk. The epidemiology of these infections has undergone notable changes over the years due to multifactorial reasons, including the evolution of protocols that intensify immunosuppression. In this context, the emergence of multi-drug resistance (MDR) microorganisms can be a challenge due to the elevated risk of mortality in these vulnerable patients. Unfortunately, there is a lack of comprehensive data on this topic, particularly in pediatrics. This article aims to provide a summary of the epidemiology of BSI in the different post-transplant phases and the impact of MDR pathogens. Having knowledge about the local epidemiology of BSI can be instrumental in tailoring targeted therapies, leading to improved survival rates in HSCT recipients.

Risk factors for bloodstream infection in paediatric haematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

Haematopoietic stem cell transplantation (HSCT), a standard treatment for paediatric haematological diseases, is highly associated with bloodstream infection (BSI), which may increase mortality.

AIM

To explore the risk factors for BSI in paediatric HSCT recipients.

METHODS

Three English databases and four Chinese databases were searched from inception to March 17th, 2022. Eligible studies included randomized controlled trials, cohort studies, and case-control studies that enrolled HSCT recipients aged ≤18 years and reported BSI risk factors. Two reviewers independently screened studies, extracted data, and assessed the risk of bias. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE), certainty of body of evidence was assessed.

FINDINGS

Fourteen studies involving 4602 persons were included. The incidences of BSI and associated mortality in paediatric HSCT recipients were approximately 10-50% and 5-15%, respectively. Meta-analysis of all studies revealed that previous BSI before HSCT (relative effect (RE): 2.28; 95% confidence interval (CI) 1.19-4.34, moderate certainty) and receiving an umbilical cord blood transplant (RE: 1.55; 95% CI: 1.22-1.97, moderate certainty) were probably associated with an increased risk of BSI. Meta-analysis of studies with low risk of bias reassured that previous BSI before HSCT probably increased the risk of BSI (RE: 2.28; 95% CI: 1.19-4.34, moderate certainty), and revealed that steroid use (RE: 2.72; 95% CI: 1.31-5.64, moderate certainty) was likely a risk factor whereas autologous HSCT was probably a protective factor of BSI (RE: 0.65; 95% CI: 0.45-0.94, moderate certainty).

CONCLUSION

These findings could inform the management of paediatric HSCT recipients, helping identify who may benefit from prophylactic antibiotics.

A Narrative Review of Healthcare-Associated Gram-Negative Infections Among Pediatric Patients in Middle Eastern Countries

INTRODUCTION

Gram-negative bacteria (GNB) have become prominent across healthcare and community settings due to factors including lack of effective infection control and prevention (ICP) and antimicrobial stewardship programs (ASPs), GNB developing antimicrobial resistance (AMR), and difficulty treating infections. This review summarizes available literature on healthcare-associated infections (HAIs) in Middle Eastern pediatric patients.

METHODS

Literature searches were performed with PubMed and Embase databases. Articles not reporting data on GNB, HAIs, pediatric patients, and countries of interest were excluded.

RESULTS

The searches resulted in 220 publications, of which 49 met the inclusion criteria and 1 additional study was identified manually. Among 19 studies across Egypt reporting GNB prevalence among pediatric patients, Klebsiella species/K. pneumoniae and Escherichia coli were typically the most common GNB infections; among studies reporting carbapenem resistance and multidrug resistance (MDR), rates reached 86% and 100%, respectively. Similarly, in Saudi Arabia, Klebsiella spp./K. pneumoniae and E. coli were the GNB most consistently associated with infections, and carbapenem resistance (up to 100%) and MDR (up to 75%) were frequently observed. In other Gulf Cooperation Council countries, including Kuwait, Oman, and Qatar, carbapenem resistance and MDR were also commonly reported. In Jordan and Lebanon, E. coli and Klebsiella spp./K. pneumoniae were the most common GNB isolates, and AMR rates reached 100%.

DISCUSSION

This review indicated the prevalence of GNB-causing HAIs among pediatric patients in Middle Eastern countries, with studies varying in reporting GNB and AMR. Most publications reported antimicrobial susceptibility of isolated GNB strains, with high prevalence of extended-spectrum beta-lactamase-producing K. pneumoniae and E. coli isolates. A review of ASPs highlighted the lack of data available in the region.

CONCLUSIONS

Enhanced implementation of ICP, ASPs, and AMR surveillance is necessary to better understand the widespread burden of antimicrobial-resistant GNB and to better manage GNB-associated HAIs across Middle Eastern countries.

Incidence, Risk Factors and Outcome of Bloodstream Infections in Patients After Hematopoietic Stem-Cell Transplantation: A Single Center Study

The bloodstream infections (BSIs) are among the most common infectious complications after hematopoietic stem-cell transplantation (HSCT), often associated with high mortality rates. The aim of this study was to evaluate the incidence, risk factors and outcome of BSIs in HSCT recipients from the Transplantation Center of the University Hospital in Varna, Bulgaria during the period January 2019-December 2021. The role of patient- and transplantation-related variables was studied as potential risk factors for BSIs and survival after HSCT. Seventy-four patients were included in the study. The cumulative incidence of BSIs was 35%. The mean period of BSI onset after HSCT was 8 days. The Gram-positive bacteria were more commonly isolated as causative agents (52.3%). The mortality rate 30 days after the diagnosis of BSI was 23%. Fecal colonization with multidrug-resistant (MDR) bacteria (p = 0.005) and pre-transplant BSI (p = 0.05) were associated with significantly increased risk for post-HSCT BSIs. The overall 4-month survival was 86.5%. A statistical significance was found between the type of the underlying disease (acute leukemia and lymphoma, p = 0.043), previous HSCT (p = 0.001) and 4-month survival. This study confirms that the fecal colonization with MDR bacteria before transplantation and pre-transplant BSIs are independent risk factors for the occurrence of BSI in the early period after HSCT. Pre- and posttransplant monitoring of the patient fecal colonization status with MDR organisms, could contribute considerably to the prevention and successful management of the infectious complications in patients after HSCT.

Active Screening of Intestinal Colonization of Carbapenem-Resistant Enterobacteriaceae for Subsequent Bloodstream Infection in Allogeneic Hematopoietic Stem Cell Transplantation

Purpose

To investigate the prevalence, risk factors of intestinal carbapenem-resistant Enterobacteriaceae (CRE) colonization and bloodstream infection (BSI) caused by CRE in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients.

Methods

We analyzed the clinical data of 185 patients with hematological malignancies who underwent allo-HSCT from May 2019 to December 2021. All patients received regular CRE monitoring by rectal swab during allo-HSCT, and some CRE strains were further identified for carbapenemase phenotypes. The rates, distribution and risk factors of CRE colonization, CRE-induced BSI were analyzed.

Results

CRE was detected in 44 of 185 recipients, with colonization rate of 23.8%. A total of 46 strains of CRE were isolated, including 22 Escherichia coli, 17 Klebsiella pneumoniae, three Klebsiella oxytoca, two Enterobacter hormaechei, and two other Enterobacteriaceae. Among the 19 strains identified with carbapenemase phenotypes, eight strains of E. coli produced metal β-lactamase, five K. pneumoniae produced serine carbapenemase, two K. pneumoniae produced metal β-lactamase, two K. oxytoca produced metal β-lactamase, a Citrobacter malonic acid-free produced metal β-lactamase and a Citrobacter freundii produced metal β-lactamase. In 10 patients developed with CRE-related BSI, the types and combined drug sensitivity of strains detected by rectal swab were highly consistent with blood culture. Multivariate analysis revealed that pulmonary infection, perianal infection and carbapenem application in the 3 months pre-transplant were independent risk factors for rectal CRE colonization, while rectal colonization with carbapenem-resistant K. pneumoniae (CR-KP) was an independent risk factor for CRE-induced BSI. The mortality rate within 30 days of CRE-related BSI was 50.0%, and patients receiving multi-drug therapy within 24 hours showed slightly lower mortality than that in the single-drug treatment group.

Conclusion

Allo-HSCT patients with CRE-induced BSI have poor prognosis, and CR-KP rectal colonization is an independent risk factor for CRE-related BSI. Rectal swab screening during allo-HSCT could provide early warning for later CRE-induced BSI.

Epidemiology of early infections and predictors of mortality after autologous hematopoietic stem-cell transplantation among multiple myeloma, Hodgkin, and non-Hodgkin lymphoma: the first experience from Palestine

Background

Autologous hematopoietic stem-cell transplantation (HSCT) is the standard of care in many relapsed and refractory lymphoid malignancy, neuroblastoma, and multiple myeloma (MM). This study was conducted to describe the epidemiology of early infections that occurred within the first 100 days among patients who received HSCT for MM, Hodgkin (HL), and non-Hodgkin lymphoma (NHL) in Palestine.

Methods

This study was conducted in a retrospective cohort design in the only autologous HSCT in Palestine in the period between 2014 and 2021. The medical records of the patients were reviewed to identify and collect demographic, clinical, and microbiological data on bacterial, viral, fungal, and parasitic infections as diagnosed by cultures, polymerase chain reaction, and fluorescent antibody testing.

Results

A total of 145 patients were included in this study (median age = 44.0 [28.0, 53.5] years). Of those, 8 (5.5%) were younger than 18 years, 69 (47.6%) had MM, 53 (36.6%) had HL, and 23 (15.9%) had NHL. The source of fever had no focus in the majority of the cases 82 (56.6%), 12 (8.3%) had bloodstream infections, 8 (5.5%) had colitis, and 7.6 (5.0%) had pneumonia. Patients from whom gram-negative bacteria were isolated stayed in the hospital for longer duration compared to the other patients (median = 21.0 [19.0, 25.0] vs. 18.0 [15.0, 22.0] days, p-value = 0.043, respectively). The cumulative incidence of death in the first 100 days after infusion of stem cells was 3.4%. The cumulative incidence of death in the first 100 days post-transplantation was higher for patients with NHL compared to those with HL and MM (p-value = 0.017). Gram-negative and fungal infections were strong predictors of mortality.

Conclusion

Bacterial gram-positive and gram-negative infections were the most common early infections among patients who underwent autologous HSCT for hematological malignancies (HM) in the only center in Palestine. The findings of this study are informative to healthcare providers and planners of care for patients who are scheduled to receive autologous HSCT for HM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07709-4.

American Society of Transplantation and Cellular Therapy Series, 1: Enterobacterales Infection Prevention and Management after Hematopoietic Cell Transplantation

The Practice Guidelines Committee of the American Society of Transplantation and Cellular Therapy partnered with its Transplant Infectious Disease Special Interest Group to update its 2009 compendium-style infectious diseases guidelines for hematopoietic cell transplantation (HCT). A completely fresh approach was taken, with the goal of better serving clinical providers by publishing each stand-alone topic in the infectious diseases series in a concise format of frequently asked questions (FAQs), tables, and figures [1]. Adult and pediatric infectious diseases and HCT content experts developed and then answered FAQs, and then finalized topics with harmonized recommendations that were made by assigning a strength of recommendation ranging from A to E paired with a level of supporting evidence graded I to III. The first topic in the series focuses on potentially life-threatening infections in HCT caused by Enterobacterales, relevant infection risk factors, and practical considerations regarding prevention and treatment of these infections in the setting of emerging multidrug resistance.

Clinical Analysis of Bloodstream Infections During Agranulocytosis After Allogeneic Hematopoietic Stem Cell Transplantation

Purpose

To explore the epidemiological characteristics and risk factors of bloodstream infections (BSI) in patients who develop agranulocytosis fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study also provides a basis for the clinical treatment of BSI.

Methods

A retrospective analysis of 397 allo-HSCT patients in the Department of Hematology of our hospital was conducted from January 2013 to December 2017 to analyze the incidence of BSI, the distribution and types of pathogenic bacteria, and drug resistance rates. We also determined whether various parameters are risk factors to BSI, including the patient age, gender, disease type, transplantation method, stem cell source, pre-treatment with anti-thymocyte globulin (ATG), and agranulocytosis time.

Results

Among the 397 allo-HSCT patients, 294 had a fever during the period of agranulocytosis, and 52 cases were found to have BSI. The incidence of BSI in patients with agranulocytosis fever was 17.7% (52/294). Among the 60 pathogens detected, 43 (71.67%), 10 (16.67%), and 7 (11.67%) were Gram negative strains, Gram positive strains, and fungi, respectively. The most common bacteria were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The detection rate of extended-spectrum β-lactamase (ESBL) was 40.0%, and carbapenem-resistant Enterobacteriaceae (CRE) accounted for 17.9%. Single-factor and multi-factor analyses showed that pre-treatment with ATG, agranulocytosis time (≥21 days), and stem cell source were risk factors for BSI.

Conclusion

We found that in our hospital, BSIs in allo-HSCT patients are mainly caused by Gram-negative bacteria, and the resistance rate to carbapenem drugs is high. Pre-treatment with ATG, agranulocytosis time (≥21 days), and stem cell source are risk factors for BSI.