Outcomes after bloodstream infection in hospitalized pediatric hematology/oncology and stem cell transplant patients

Levofloxacin prophylaxis in pediatric oncology and hematopoietic stem cell transplantation: a literature review

Bloodstream infections (BSI) are one of the leading causes of morbidity and mortality in children and young adults receiving chemotherapy for malignancy or undergoing hematopoietic stem cell transplantation (HSCT). Antibiotic prophylaxis is commonly used to decrease the risk of BSI; however, antibiotics carry an inherent risk of complications. The aim of this manuscript is to review levofloxacin prophylaxis in pediatric oncology patients and HSCT recipients. We reviewed published literature on levofloxacin prophylaxis to prevent BSI in pediatric oncology patients and HSCT recipients. Nine manuscripts were identified. The use of levofloxacin is indicated in neutropenic children and young adults receiving intensive chemotherapy for leukemia or undergoing HSCT. These results support the efficacy of levofloxacin in pediatric patients with leukemia receiving intensive chemotherapy and should be considered in pediatric patients undergoing HSCT prior to engraftment.

Microbiota Predict Infections and Acute Graft-Versus-Host Disease After Pediatric Allogeneic Hematopoietic Stem Cell Transplantation

BACKGROUND

Despite preventive measures, infections continue to pose significant risks to pediatric allogeneic hematopoietic cell transplantation (allo-HCT) recipients. The gut microbiota has been linked to clinical outcomes following adult allo-HCT. This study evaluated whether similar disruptions or differing microbiota patterns were associated with infection risk in pediatric allo-HCT.

METHODS

In a prospective observational study, fecal samples were obtained from 74 children before conditioning and upon neutrophil recovery. Microbiome signatures identified through sequencing were examined for their associations with infections or acute graft-versus-host disease (aGVHD) in the first-year post-HCT using Cox proportional hazards analysis.

RESULTS

Microbiome disruption in adults, did not predict infection risk in pediatric allo-HCT. Unique microbiota signatures were associated with different infections or aGVHD. A ratio of strict and facultative anaerobes (eg, Lachnoclostridium, Parabacteroides) prior to conditioning predicted bacteremia risk (Cox hazard ratio [HR], 3.89). A distinct ratio of oral (eg, Rothia, Veillonella) to intestinal anaerobes (eg, Anaerobutyricum, Romboutsia) at neutrophil recovery predicted likelihood of bacterial infections (Cox HR, 1.81) and viral enterocolitis (Cox HR, 1.96).

CONCLUSIONS

Interactions between medical interventions, pediatric hosts, and microbial communities contribute to microbiota signatures that predict infections. Further multicenter study is necessary to validate the generalizability of these ratios as biomarkers.

Infections in Children with Cancer Admitted in an Oncology Reference Hospital: A Cross-sectional Study

Pediatric oncology patients are usually immunosuppressed due to factors such as the neoplasm and its treatment, making them more susceptible to infections. This article aims to determine the infection profile of pediatric oncology patients admitted to an oncology reference hospital in Natal, Rio Grande do Norte, Brazil. A retrospective and cross-sectional study was conducted, collecting data from patients hospitalized due to infection in a pediatric oncology unit exclusively for the Brazilian public health system, spanning from 2018 to 2021. A total of 168 episodes of infections were identified in 96 patients, resulting in 157 hospitalizations. Among the patients with infections, 62.4% had hematological malignancies, and out of these cases, 74.6% specifically had Acute Lymphoid Leukemia. The Escherichia coli (31.9%) was the most prevalent microorganism isolated from the samples. Multidrug-resistant microorganisms accounted for 52% of all identified microorganisms. Fluoroquinolones and beta-lactam were the most prevalent antibiotic classes in the analyzed antibiograms. Factors such as Sex, type of cancer, chemotherapy in the last 30 days, were found to be associated with the occurrence of infection (p < 0.05). Conducting epidemiological studies regarding infections in pediatric oncology is crucial to development of empirical protocols, and the implementation of strategies to better control future infections.

Chlorhexidine gluconate (CHG) foam improves adherence, satisfaction, and maintains central line associated infection rates compared to CHG wipes in pediatric hematology-oncology and bone marrow transplant patients

CHG-based hygiene methods are often a component of daily hygiene bundles to prevent central line-associated blood stream infections (CLABSIs) in pediatric hematology-oncology patients; however, adherence with 2% CHG wipes was inconsistent within our institution, risking infection for immunocompromised patients. A new 4% CHG foam method offers an alternative and is applied while bathing, as opposed to wipes used 1 h after bathing. An initial cohort of 24 high-risk oncology and bone marrow transplant (BMT) patients agreed to use 4% CHG foam in place of wipes, and then answered surveys to describe their experiences. Ninety-two percent preferred foam over wipes and were more likely to use the foam moving forward. CHG foam was then made available as an option to all patients in need of central line care upon admission to the hospital. Hygiene bundles in the electronic medical record were reviewed to measure baseline adherence rates. Random audits by nursing administration prospectively assessed CHG adherence. CLABSI data were collected prospectively with routine quality metric reports. Results were analyzed using run charts and u-charts, respectively. Hematology-Oncology unit adherence rates remained at a higher rate of adherence, and BMT unit adherence rates increased from an average of 55%-81.6% (p < 0.001). Primary CLABSIs remained rare events (average <1/1000 CVL days). On cost analysis, utilizing CHG foam results in an annual savings estimate of $40,000 for a 24-bed unit. In conclusion, 4% CHG foam provides a cost-effective and patient-preferred option for daily hygiene that maintains CLABSI preventative efforts.

A Novel Oncodental Collaborative Team: Integrating Expertise for Central Line-Associated Bloodstream Infection Prevention in Pediatric Oncology Patients

PURPOSE

Pediatric oncology and bone marrow transplant patients are at high risk of infection, and limitations to dental expertise among medical providers render patients vulnerable to central line-associated bloodstream infections from oral pathogens. Traditionally, oral health maintenance relied on patients and bedside nurses; however, routine methods are often suboptimal to prevent central line-associated bloodstream infection in high-risk patients. Limited overlap of medical and dental expertise, and limited dental resources in typical oncology units, prevent optimal oral care for children with cancer, requiring novel solutions to better integrate specialties.

METHODS

Here, we outline the creation of a novel Pediatric oncodental team to address oral-systemic infection prevention strategies for high-risk patients.

RESULTS

Our oncology and dental teams created a systematic approach for increasing oral surveillance and treatment in select high-risk patients. Supervised pediatric dental residents participated in scheduled oncology rounds, and a permanent oral health educator with a background in dental hygiene was also hired as a dedicated dental professional within our oncology department.

CONCLUSION

Our pediatric oncodental team aims to sustain optimal oral complication prevention strategies to reduce the risk of infection, provide education on the significance of the oral-systemic link in cancer care, and improve access and continuity of care.

Effectiveness of Quinolone Prophylaxis in Pediatric Acute Leukemia and Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-analysis

The effectiveness of quinolone prophylaxis in high-risk hematological pediatric patients is controversial. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, including studies that involved children and young adults undergoing chemotherapy for acute leukemia or hematopoietic stem cell transplantation (HSCT) who received quinolone prophylaxis compared with no prophylaxis. A meta-analysis was performed on bloodstream infections and neutropenic fever. Data regarding the impact of prophylaxis on overall survival, antibiotic exposure, antibiotic-related adverse effects, antibiotic resistance, Clostridium difficile infections, fungal infections, length of hospitalization, and costs were reviewed in the descriptive analysis. Sixteen studies were included in the qualitative analysis, and 10 of them met the criteria for quantitative analysis. Quinolone prophylaxis was effective in reducing the rate of bloodstream infections and neutropenic fever in pediatric acute leukemia compared with no prophylaxis, but it had no significant effect in HSCT recipients. Prophylaxis was associated with a higher rate of bacterial resistance to fluoroquinolones and higher antibiotic exposure.

Microbiota dynamics in a randomized trial of gut decontamination during allogeneic hematopoietic cell transplantation

BACKGROUNDGut decontamination (GD) can decrease the incidence and severity of acute graft-versus-host disease (aGVHD) in murine models of allogeneic hematopoietic cell transplantation (HCT). In this pilot study, we examined the impact of GD on gut microbiome composition and the incidence of aGVHD in HCT patients.METHODSWe randomized 20 patients undergoing allogeneic HCT to receive (GD) or not receive (no-GD) oral vancomycin-polymyxin B from day -5 through neutrophil engraftment. We evaluated shotgun metagenomic sequencing of serial stool samples to compare the composition and diversity of the gut microbiome between study arms. We assessed clinical outcomes in the 2 arms and performed strain-specific analyses of pathogens that caused bloodstream infections (BSI).RESULTSThe 2 arms did not differ in the predefined primary outcome of Shannon diversity of the gut microbiome at 2 weeks post-HCT (genus, P = 0.8; species, P = 0.44) or aGVHD incidence (P = 0.58). Immune reconstitution of T cell and B cell subsets was similar between groups. Five patients in the no-GD arm had 8 BSI episodes versus 1 episode in the GD arm (P = 0.09). The BSI-causing pathogens were traceable to the gut in 7 of 8 BSI episodes in the no-GD arm, including Staphylococcus species.CONCLUSIONWhile GD did not differentially affect Shannon diversity or clinical outcomes, our findings suggest that GD may protect against gut-derived BSI in HCT patients by decreasing the prevalence or abundance of gut pathogens.TRIAL REGISTRATIONClinicalTrials.gov NCT02641236.FUNDINGNIH, Damon Runyon Cancer Research Foundation, V Foundation, Sloan Foundation, Emerson Collective, and Stanford Maternal & Child Health Research Institute.

Bacteremia in Children with Solid Tumors: Etiology, Antimicrobial Susceptibility, Factors Associated with Multidrug Resistance, and Mortality

This retrospective study aims to describe the etiology and resistance patterns of pathogens causing bacteremia in children with solid tumors in a tertiary pediatric hematology-oncology center in Jerusalem, Israel (2011-2019). Factors associated with multidrug-resistant (MDR) bacteremia and mortality were analyzed. A total of 228 pathogens were isolated in 126 patients; 61.0% were gram-negative rods (GNR) and 38.2% were gram-positive cocci (GPC). The most common pathogens were Klebsiella pneumoniae (19.3%), Escherichia coli (17.5%), and coagulase-negative staphylococci (16.2%). The proportion of MDR-GNR was 18.2%, while the proportion of MDR-GPC was 55.2%. In logistic regression analysis, breakthrough bacteremia on a penicillin-group antibiotic (odds ratio [OR] 5.69, [95% confidence interval 1.42-22.76], p-value = 0.014) was associated and underlying diagnosis of neuroblastoma was inversely associated (OR 0.17, [0.04-0.81], p-value = 0.026) with MDR-GNR bacteremia; while the previous hospitalizations' duration (OR 1.032/day, [1.01-1.06], p-value = 0.007) and oncologic treatment intensity (OR 2.19, [1.08-4.45, p-value = 0.03) were associated with MDR-GPC bacteremia. Shock, prolonged profound neutropenia, and pediatric intensive care unit (PICU) admission were associated with 7-day mortality; and relapsed disease, oncologic treatment intensity, prolonged profound neutropenia, and PICU admission-with 30-day mortality in the univariate analyses. Empirical antibiotic choice should be based on factors associated with MDR infections in this specific population.

Levofloxacin Versus Ciprofloxacin-Based Prophylaxis during the Pre-Engraftment Phase in Allogeneic Hematopoietic Stem Cell Transplant Pediatric Recipients: A Single-Center Retrospective Matched Analysis

Infectious complications are the most common and significant cause of mortality and morbidity after allogeneic hematopoietic stem cell transplantation (HSCT). Antibacterial prophylaxis in pediatric cancer patients is a controversial issue. Our study compared the outcomes of levofloxacin versus ciprofloxacin prophylaxis in allogeneic HSCT pediatric recipients treated for hematological malignancies. A total of 120 patients received levofloxacin prophylaxis, and 60 patients received ciprofloxacin prophylaxis. Baseline characteristics such as age, gender, primary diagnosis, type of conditioning, donor type, stem cell source, and supportive care of the patients were similar, and duration of antibiotics prophylaxis was similar. Both prophylaxis regimens demonstrated the same efficacy on the risk of febrile neutropenia and severe complications such as sepsis, the same rate of overall mortality, hospital readmission, and length of hospital stay. Levofloxacin prophylaxis was associated with significantly lower cumulative antibiotic exposure. The median of Gram-positive infection-related antibiotic days was 10 days in the levofloxacin group versus 25 days in the ciprofloxacin group (p < 0.0001). The median of Gram-negative infection-related antibiotics was 10 days in the levofloxacin group compared with 20 days in the ciprofloxacin group (p < 0.0001). The number of days with body temperature ≥38 °C was significantly less in the levofloxacin group (p < 0.001).

Transplant-associated thrombotic microangiopathy: elucidating prevention strategies and identifying high-risk patients

INTRODUCTION

Hematopoietic stem cell transplantation-associated thrombotic microangiopathy (TA-TMA) is a severe complication of transplant. TA-TMA is a multifactorial disease where generalized endothelial dysfunction leads to microangiopathic hemolytic anemia, intravascular platelet activation, and formation of microthrombi leading to end-organ injury. It is essential to identify patients at risk for this complication and to implement early interventions to improve TA-TMA associated transplant outcomes.

AREAS COVERED

Recognition of TA-TMA and associated multi-organ injury, risk predictors, contributing factors, differential diagnosis and targeting complement pathway in TA-TMA by summarizing peer reviewed manuscripts.

EXPERT OPINION

TA-TMA is an important transplant complication. Diagnostic and risk criteria are established in children and young adults and risk-based targeted therapies have been proposed using complement blockers. The immediate goal is to extend this work into adult stem cell transplant recipients by implementing universal TA-TMA screening practices. This will facilitate early TA-TMA diagnosis and targeted interventions, which will further improve survival. While complement blocking therapy is effective, about one third of patients are refractory to treatment and those patients commonly die. The next hurdle for the field is identifying reasons for failure, optimizing strategies for complement modifying therapy and searching for additional targetable pathways of endothelial injury.

Simulated Pediatric Blood Cultures to Assess the Inactivation of Clinically Relevant Antimicrobial Drug Concentrations in Resin-Containing Bottles

The bacteremia level as well as the administration of antibiotics before blood collection may significantly affect the recovery of bacterial pathogens from pediatric blood cultures in BacT/Alert Virtuo or Bactec FX BC systems, which remain the common techniques to diagnose bacteremia in pediatric patients. We simulated pediatric blood cultures with low or intermediate bacteremia level to evaluate BacT/Alert PF Plus and Bactec Peds Plus blood culture bottles for resin-based inactivation of 16 antibiotic-bacterium combinations. Overall, 105/192 (54.7%) of BacT/Alert PF Plus bottles and 69/192 (36.0%) of Bactec Peds Plus bottles allowed organisms to grow when exposed to antibiotics. In particular, both BacT/Alert PF Plus and Bactec Peds Plus bottles proved to be effective with piperacillin/tazobactam and Pseudomonas aeruginosa or with oxacillin and methicillin-susceptible Staphylococcus aureus (100% growth), whereas no effectiveness was apparent with ceftriaxone and Escherichia coli, Streptococcus agalactiae, or Streptococcus pneumoniae or with cefepime and E. coli (0% growth). In some relevant instances (e.g., with vancomycin and methicillin-resistant S. aureus or Streptococcus pneumoniae), BacT/Alert PF Plus bottles were superior to Bactec Peds Plus bottles. Together, these findings underscore the potentiality of resin-containing bottles to enhance diagnosis of bacteremia in pediatric patients on antimicrobial therapy. This is particularly true with one of the evaluated BC systems and with simulated intermediate bacteremia level only.

The gut microbiome in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation

The gut microbiome (GM) has been associated with different clinical outcomes in the context of allogeneic hematopoietic stem cell transplantation (HSCT). Large multicenter cohort studies in adults have found significant correlations with overall survival, relapse, and incidence of complications. Moreover, GM is already a promising target for therapeutic interventions. However, few data are available in children, a population presenting unique features and challenges. During childhood, the GM evolves rapidly with large structural fluctuations, alongside with the maturation of the immune system. Furthermore, the HSCT procedure presents significant differences in children. These considerations underline the importance of a specific focus on the pediatric setting, and the role of GM and its age-dependent trajectory in influencing the immunity reconstitution and clinical outcomes. This review provides a comprehensive overview of the available evidence in the field of GM and pediatric HSCT, highlighting age-specific issues and discussing GM-based therapeutic approaches.

Alcohol-impregnated caps and ambulatory central-line-associated bloodstream infections (CLABSIs): A randomized clinical trial

OBJECTIVE

To evaluate the effect of 70% isopropyl alcohol-impregnated central venous catheter caps on ambulatory central-line-associated bloodstream infections (CLABSIs) in pediatric hematology-oncology patients.

DESIGN

This study was a 24-month, cluster-randomized, 2 period, crossover clinical trial.

SETTING

The study was conducted in 15 pediatric healthcare institutions, including 16 pediatric hematology-oncology clinics.

PARTICIPANTS

All patients with an external central line followed at 1 of the 16 hematology-oncology clinics.

INTERVENTION

Usual ambulatory central-line care per each institution using 70% isopropyl alcohol-impregnated caps at home compared to usual ambulatory central-line care in each institution without using 70% isopropyl alcohol-impregnated caps.

RESULTS

Of the 16 participating clinics, 15 clinics completed both assignment periods. As assigned, there was no reduction in CLABSI incidence in clinics using 70% isopropyl alcohol-impregnated caps (1.23 per 1,000 days) compared with standard practices (1.38 per 1,000 days; adjusted incidence rate ratio [aIRR], 0.83; 95% CI, 0.63-1.11). In the per-protocol population, there was a reduction in positive blood culture incidence in clinics using 70% isopropyl alcohol-impregnated caps (1.51 per 1,000 days) compared with standard practices (1.88 per 1,000 days; aIRR, 0.72; 95% CI, 0.52-0.99). No adverse events were reported.

CONCLUSIONS

Isopropyl alcohol-impregnated central-line caps did not lead to a statistically significant reduction in CLABSI rates in ambulatory hematology-oncology patients. In the per-protocol analysis, there was a statistically significant decrease in positive blood cultures. Larger trials are needed to elucidate the impact of 70% isopropyl alcohol-impregnated caps in the ambulatory setting.

REGISTRATION

ClinicalTrials.gov; NCT02351258.

Improving Oral Health and Modulating the Oral Microbiome to Reduce Bloodstream Infections from Oral Organisms in Pediatric and Young Adult Hematopoietic Stem Cell Transplantation Recipients: A Randomized Controlled Trial

Bloodstream infections (BSIs) from oral organisms are a significant cause of morbidity and mortality in hematopoietic stem cell transplantation (HSCT) recipients. There are no proven strategies to decrease BSIs from oral organisms. The aim of this study was to evaluate the impact of daily xylitol wipes in improving oral health, decreasing BSI from oral organisms, and modulating the oral microbiome in pediatric HSCT recipients. This was a single-center 1:1 randomized controlled trial in pediatric HSCT recipients age >2 years. Age-matched healthy children were enrolled to compare the oral microbiome. The oral hygiene standard of care (SOC) group continued to receive the standard oral hygiene regimen. The xylitol group received daily oral xylitol wipes (with .7 g xylitol) in addition to the SOC. The intervention started from the beginning of the transplantation chemotherapy regimen and extended to 28 days following transplantation. The primary outcome was oral health at interval time points, and secondary outcomes included BSIs from oral organisms in the first 30 days following transplantation, oral microbiome abundance, and diversity and oral pathogenic organism abundance. The study was closed early due to efficacy after an interim analysis of the first 30 HSCT recipients was performed (SOC group, n = 16; xylitol group, n = 14). The xylitol group had a significantly lower rate of gingivitis at days 7, 14, and 28 following transplantation (P = .031, .0039, and .0005, respectively); oral plaque at days 7 and 14 (P = .045 and .0023, respectively); and oral ulcers >10 mm at day 14 (P = .049) compared with the SOC group. The xylitol group had no BSI from oral organisms compared with the SOC group, which had 4 (P = .04). The xylitol group had significantly lower abundance of potential BSI pathogens, such as Staphylococcus aureus (P = .036), Klebsiella pneumoniae (P = .033), and Streptococcus spp (P = .011) at the day after transplantation compared with the SOC group. Healthy children and young adults had significantly increased oral microbiome diversity compared with all HSCT recipients (P < .001). The addition of xylitol to standard oral care significantly improves oral health, decreases BSI from oral organisms, and decreases the abundance of pathogenic oral organisms in pediatric and young adult HSCT recipients.

Incidence, Risk Factors, and Outcomes of Patients Who Develop Mucosal Barrier Injury-Laboratory Confirmed Bloodstream Infections in the First 100 Days After Allogeneic Hematopoietic Stem Cell Transplant

IMPORTANCE

Patients undergoing hematopoietic stem cell transplant (HSCT) are at risk for bloodstream infection (BSI) secondary to translocation of bacteria through the injured mucosa, termed mucosal barrier injury-laboratory confirmed bloodstream infection (MBI-LCBI), in addition to BSI secondary to indwelling catheters and infection at other sites (BSI-other).

OBJECTIVE

To determine the incidence, timing, risk factors, and outcomes of patients who develop MBI-LCBI in the first 100 days after HSCT.

DESIGN, SETTING, AND PARTICIPANTS

A case-cohort retrospective analysis was performed using data from the Center for International Blood and Marrow Transplant Research database on 16 875 consecutive pediatric and adult patients receiving a first allogeneic HSCT from January 1, 2009, to December 31, 2016. Patients were classified into 4 categories: MBI-LCBI (1481 [8.8%]), MBI-LCBI and BSI-other (698 [4.1%]), BSI-other only (2928 [17.4%]), and controls with no BSI (11 768 [69.7%]). Statistical analysis was performed from April 5 to July 17, 2018.

MAIN OUTCOMES AND MEASURES

Demographic characteristics and outcomes, including overall survival, chronic graft-vs-host disease, and transplant-related mortality (only for patients with malignant disease), were compared among groups.

RESULTS

Of the 16 875 patients in the study (9737 [57.7%] male; median [range] age, 47 [0.04-82] years) 13 686 (81.1%) underwent HSCT for a malignant neoplasm, and 3189 (18.9%) underwent HSCT for a nonmalignant condition. The cumulative incidence of MBI-LCBI was 13% (99% CI, 12%-13%) by day 100, and the cumulative incidence of BSI-other was 21% (99% CI, 21%-22%) by day 100. Median (range) time from transplant to first MBI-LCBI was 8 (<1 to 98) days vs 29 (<1 to 100) days for BSI-other. Multivariable analysis revealed an increased risk of MBI-LCBI with poor Karnofsky/Lansky performance status (hazard ratio [HR], 1.21 [99% CI, 1.04-1.41]), cord blood grafts (HR, 2.89 [99% CI, 1.97-4.24]), myeloablative conditioning (HR, 1.46 [99% CI, 1.19-1.78]), and posttransplant cyclophosphamide graft-vs-host disease prophylaxis (HR, 1.85 [99% CI, 1.38-2.48]). One-year mortality was significantly higher for patients with MBI-LCBI (HR, 1.81 [99% CI, 1.56-2.12]), BSI-other (HR, 1.81 [99% CI, 1.60-2.06]), and MBI-LCBI plus BSI-other (HR, 2.65 [99% CI, 2.17-3.24]) compared with controls. Infection was more commonly reported as a cause of death for patients with MBI-LCBI (139 of 740 [18.8%]), BSI (251 of 1537 [16.3%]), and MBI-LCBI plus BSI (94 of 435 [21.6%]) than for controls (566 of 4740 [11.9%]).

CONCLUSIONS AND RELEVANCE

In this cohort study, MBI-LCBI, in addition to any BSIs, were associated with significant morbidity and mortality after HSCT. Further investigation into risk reduction should be a clinical and scientific priority in this patient population.