Infections with viridans group streptococci in children with cancer

Retrospective Observational Assessment of the Impact of Cefepime Prophylaxis in Neutropenic Pediatric Patients With Acute Myelogenous Leukemia

BACKGROUND

The potential for cefepime prophylaxis to reduce bloodstream infections (BSIs) in pediatric patients with acute myelogenous leukemia (AML) has been incompletely characterized.

METHODS

A retrospective quasi-experimental study of patients under 21 years of age admitted with AML from 2010 through 2018 at two affiliated pediatric tertiary-care hospitals before and after the adoption of routine cefepime prophylaxis for afebrile AML patients during profound neutropenia.

RESULTS

The rate of BSIs per 1000 neutropenia days was significantly lower in the prophylaxis group than the baseline group (2.6 vs 15.5, incidence rate ratio [IRR] 0.17, 95% CI 0.09-0.32). Interrupted time-series analysis showed that a sharp reduction in BSIs coincided with the implementation of prophylaxis. Bacteremia with viridans group streptococci was frequent in the baseline group but not observed after adopting prophylaxis. Despite the increased use of cefepime, the rate of cefepime-nonsusceptible BSIs per 1000 neutropenia days decreased (1.6 vs 4.1, IRR 0.40, 95% CI 0.16-0.99). The median number of febrile neutropenia episodes per patient also decreased in the prophylaxis group, as did the proportion of patients admitted to the intensive care unit (ICU) (22/51 (43.1%) vs 26/38 (68.4%); risk difference -25.3%, 95% CI -44.4 to -2.8). A trend was observed toward an increased proportion of patients with Clostridioides difficile infection in the prophylaxis group (10/51 (19.6%) vs 3/38 (7.9%); risk difference 11.7%, 95% CI -3.4 to 29.0).

CONCLUSIONS

Cefepime prophylaxis was associated with a significant reduction in BSIs, febrile neutropenia, and ICU admission among pediatric AML patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A clinical approach to non-neutropenic fever in children with cancer

BACKGROUND

There are a limited number of studies that address non-neutropenic fever episodes in children with cancer, and no standard approach exists.

METHOD

We opt to retrospectively analyze the efficacy of the current clinical approach for management of non-neutropenic fever episodes and the associated risk factors among children with cancer at the Princess Noorah Oncology Center from May 2016 through December 2017.

RESULTS

A total of 480 non-neutropenic fever episodes were identified in 131 children, of which 62 episodes were triaged as high-risk non-neutropenic fever and 418 as low-risk non-neutropenic fever. Of those 480 non-neutropenic fever, 361 episodes (75.2%) were associated with the presence of central venous catheters. The overall failure rate of ceftriaxone mono-therapy was observed in 75.6% (11.7% in high-risk non-neutropenic fever with a mean C-reactive protein level of 21.1 (±23.2) mmol/L and 63.9% in low-risk non-neutropenic fever with a mean C-reactive protein level of 17.6 (±53.9) mmol/L). The overall bacteremia rate was 14.4%. The type of organisms isolated was mainly high-risk organisms in 59 non-neutropenic fever episodes (85.5%), OR 1.78 (95% CI: 0.45-7.04) p = 0.41. Of note, all bacteremia were associated with the presence of central venous catheter (100%). Of all the examined risk factors of outpatient treatment failure in low-risk non-neutropenic fever, only prolonged fever of more than three days were significantly associated with bacteremia OR 8.107 [95% CI: 1.744-37.691], p = 0.008. Noteworthy is that almost 43% of non-neutropenic fever episodes were associated with respiratory symptoms. This study provides a baseline for future prospective research assessing the pattern of non-neutropenic fever by focusing on associated risk factors.

Bloodstream infection by multidrug-resistant Streptococcus oralis in a leukemic patient with febrile neutropenia after hematopoietic stem cell transplantation

We reported the case of a patient with leukemia who developed febrile neutropenia after hematopoietic stem cell transplantation. Blood culture results revealed the presence of Streptococcus oralis, while antimicrobial susceptibility testing showed the resistance to penicillin and cephem. Furthermore, isolates were not susceptible to either meropenem or daptomycin but not to vancomycin. S oralis is known to belong to Streptococcus mitis group and be a causative agent of bacteremia in the neutropenic patients, but multidrug resistance of S oralis is rare. Our findings suggest that we might pay attention to the emergence of the microorganisms acquiring multidrug resistance in neutropenic patients.

Streptococcus mitis/oralis Causing Blood Stream Infections in Pediatric Patients

Viridans streptococci are still under investigation concerning epidemiology, pathogenesis and clinical presentations. We aimed to investigate the clinical presentations and outcomes of pediatric patients infected with Streptococcus mitis/oralis. Based on the accumulation of bloodstream infections (BSI) caused by S. mitis/oralis in 4 patients in our Hematology and Bone Marrow Transplantation Department at a particular time, a review of the medical and microbiological records of pediatric patients with positive blood cultures for S. mitis/oralis in the entire hospital was performed. In addition, a retrospective case-control study was conducted. Pulsed-field gel electrophoresis of S. mitis/oralis in 4 patients displayed unrelatedness of the strains. A total of 53 BSI (42 BSI and 11 catheter-related BSI) were analyzed. Thirty-four percent of patients with BSI caused by S. mitis/oralis had febrile neutropenia. Clinical and microbiological outcomes were favorable and infection-related mortality was not observed. Although not significant, previous antibiotic use and trimethoprim-sulfamethoxazole prophylaxis were more common in the case group. S. mitis/oralis seems likely an important agent in bacteremic children who are particularly neutropenic because of the underlying hematologic and oncologic diseases. Prompt management of infections with appropriate antimicrobials, regarding antibiotic susceptibilities of organisms, may facilitate favorable outcomes.

Viridans Group Streptococcal Infections in Children After Chemotherapy or Stem Cell Transplantation: A 10-year Review From a Tertiary Pediatric Hospital

Viridans Group Streptococci (VGS) are associated with high mortality rates in febrile neutropenia; yet there are no recent European pediatric studies to inform antimicrobial therapy. The aim of this study was to describe the characteristics, outcome, and resistance patterns of children with VGS bacteremia (VGSB) undergoing treatment of malignancy or hematopoietic stem cell transplant. Patients aged 0 to 18 years, admitted to a tertiary pediatric hemato-oncology center with VGSB, from 2003 to 2013, were included in the study. All data were collected retrospectively from medical records. A total of 54 bacteremic episodes occurred in 46 patients. The most common underlying diagnosis was relapsed acute lymphoblastic leukemia. Streptococcus mitis was the most frequent organism. A total of 30% of isolates were resistant to penicillin and 100% sensitive to vancomycin. There were 8 episodes (14.8%) of Viridans Group Streptococcal Shock Syndrome; 6 resulted in admission to intensive care and 3 of these patients died of multiorgan failure. The potentially fatal nature of VGSB is confirmed. The high risk in relapsed acute lymphoblastic leukemia is of note. Research is needed to develop risk-stratification scores that identify children at risk of Viridans Group Streptococcal Shock Syndrome to guide empirical antimicrobial therapy in febrile neutropenia.

The Role of Corticosteroids in Adult Respiratory Distress Syndrome caused by Viridans Group Streptococci Bacteremia in Neutropenic Patients

In the past decades, viridans group Streptococci (VGS) have emerged as an important cause of bacteremia in neutropenic patients with cancer. The clinical course of VGS bacteremia can be devastating including septic shock and adult respiratory distress syndrome (ARDS). It has been suggested that septicemia with VGS triggers the development of noncardiogenic pulmonary edema in patients with pre-existing damage of the lungs due to aggressive cytotoxic treatment. Thus, the preemptive administration of corticosteroid to patients diagnosed with VGS bacteremia with early onset of respiratory failure has been employed to prevent ARDS. While this management strategy has been suggested in the literature, little published data are available to validate this practice. In this study, we sought to review the benefit of early administration of corticosteroid to patients who developed symptom or early signs of respiratory failure while being neutropenic with VGS bacteremia.

Predictors and outcomes of viridans group streptococcal infections in pediatric acute myeloid leukemia: from the Canadian infections in AML research group

BACKGROUND

Viridans group streptococci (VGS) cause significant morbidity in children treated for acute myeloid leukemia (AML). Our goals were to determine the occurrence and impact of these infections in children treated for AML and to understand the factors that increase the risk of VGS infections and viridans streptococcal shock syndrome (VSSS) in this population.

METHODS

We conducted a retrospective, population-based cohort study that included children ≤18 years of age with de novo AML treated at 15 Canadian centers. We evaluated factors related to VGS infection and VSSS.

RESULTS

Among 341 children with AML, VGS occurred in 78 (22.9%) children over the entire course of therapy and 16 had recurrent episodes. VGS infection occurred in 97 of 1277 courses of chemotherapy (7.6%). VSSS occurred in 19.6% of these episodes and included 11 patients who required intensive care services with 2 VGS infections resulting in death. In multiple regression analysis, factors independently related to VGS included treatment on a Medical Research Council-based protocol (odds ratio (OR) 2.87, 95% confidence interval (CI) 1.53-5.39; P = 0.001), cytarabine dose per gram/m² (OR 1.04, 95% CI 1.01-1.07; P = 0.002) and prolonged neutropenia (OR 1.58, 95% CI: 0.97-2.56; P = 0.06). None of the evaluated factors were predictive of VSSS.

CONCLUSIONS

VGS infections occur in 7.6% of chemotherapy courses and remain an important cause of morbidity and even mortality in children being treated for AML. Interventions to reduce VGS need to be identified.

High frequency of streptococcal bacteraemia during childhood AML therapy irrespective of dose of cytarabine

BACKGROUND

High-dose cytarabine has been associated with a high frequency of viridans group streptococcal (VGS) bacteraemia. VGS bacteraemia causes considerable morbidity and mortality. The Nordic Society of Paediatric Haematology and Oncology (NOPHO)-AML protocols use higher cumulated doses of cytarabine and more chemotherapy series (n = 6) than other protocols with the potential increased risk of severe VGS infections.

PROCEDURE

Medical records of all Danish children enrolled on the NOPHO-AML-2004 protocol between January 2004 and September 2011 (n = 45) were retrospectively reviewed and all febrile episodes were registered.

RESULTS

Following 236 courses of chemotherapy, 112 positive blood cultures were registered. VGS were found in 38% of all positive blood cultures. Infectious episodes with VGS resulted in more days of fever and intravenous antibiotic therapy compared with infections caused by other microorganisms. VGS were involved in 45% of all episodes categorized as sepsis (n = 51) and in 67% of life-threatening bloodstream infections (n = 9). Penicillin resistance was found in 40% of the VGS strains. No significant difference was observed in the proportion of VGS isolated following courses with low-dose cytarabine versus courses with high-dose cytarabine.

CONCLUSIONS

VGS were the most commonly isolated pathogens causing the most severe infections and the majority of life-threatening infections. A substantial proportion of the strains were resistant to penicillin. The high rate of VGS seemed independent of high-dose cytarabine but was more likely caused by the intensive chemotherapy treatment leading to severe mucositis and neutropenia.

Clinical characteristics and antimicrobial susceptibilities of viridans streptococcal bacteremia during febrile neutropenia in patients with hematologic malignancies: a comparison between adults and children

Background

This study was performed to compare the clinical characteristics and antibiotic susceptibilities of viridans streptococcal bacteremia (VSB) between febrile neutropenic adults and children with hematologic malignancies.

Methods

The consecutive medical records of neutropenic patients with hematologic malignancies who were admitted to the Catholic Blood and Marrow Transplantation Center between April 2009 and July 2012, and who were subsequently diagnosed with VSB were reviewed retrospectively. A comparison was made between the clinical and laboratory characteristics of adults and pediatric patients and also between patients with cefepime susceptible or not susceptible VSB.

Results

A total of 202 episodes (141 in adults, 61 in children) of VSB were identified. Among them, 26 (12.9%) cases had severe complications including four (2.0%) cases of death attributable to VSB. For antibacterial prophylaxis, most adults received ciprofloxacin (97.1%), but children more frequently received trimethoprim/sulfamethoxazole (86.9%). Oral mucositis (p = 0.005) and abdominal pain (p = 0.001) were found more frequently in adults, and cough was found more frequently in children (p = 0.004). The occurrence rates of severe complications and death attributable to VSB were not significantly different between adults and children. Susceptibility rate to cefepime was significantly higher in adults than children (85.7% vs. 66.1%, p = 0.002). However, in multivariate analysis, cefepime susceptibility had no impact on clinical outcome.

Conclusions

There was no significant difference in clinical outcome between adults and children with VSB despite a difference in cefepime susceptibility. Hence, different antibiotic treatment strategies may not be necessary.

Clinical characteristics and antibiotic susceptibility of viridans streptococcal bacteremia in children with febrile neutropenia

PURPOSE

This retrospective study was performed in order to investigate the clinical characteristics and antibiotic susceptibility of viridans streptococcal bacteremia (VSB) in febrile neutropenic children in the context of the increase in incidence and antibiotic resistance of VSB.

METHODS

We conducted this study among neutropenic children with underlying hematology/oncology diseases who were diagnosed with VSB at a single institution from April 2009 to June 2012. Clinical and laboratory characteristics of the children as well as antibiotic susceptibility of the causative viridans streptococci were evaluated.

RESULTS

Fifty-seven episodes of VSB were diagnosed in 50 children. Severe complications occurred in four children (7.0%), and a death of one child (1.8%) was attributable to VSB. Acute myeloid leukemia was the most common underlying disease (70.2% of all cases), and 71.9% of all cases received chemotherapy including high-dose cytarabine. VSB occurred at a median of 13 days (range 8-21 days) after the beginning of chemotherapy, and fever lasted for a median of 4 days (range 1-21 days). The C-reactive protein level significantly increased within a week after the occurrence of VSB (p < 0.001) and the maximum C-reactive protein level showed a positive correlation with fever duration (r = 0.362, p = 0.007). Second blood cultures were done before the use of glycopeptides in 33 children, and negative results were observed in 30 children (90.9%). Susceptibilities to cefotaxime, cefepime, and vancomycin were 58.9, 69.1, and 100%, respectively.

CONCLUSIONS

Severe complications of VSB in neutropenic febrile children were rare. We suggest glycopeptide use according to the results of blood culture and antibiotic susceptibility tests based on the susceptibility to cefepime and the microbiologic response to empirical antibiotic treatment not including glycopeptides in this study.

Bacteremia in febrile nonneutropenic pediatric oncology patients

BACKGROUND

We sought to determine the risk of bacteremia in a cohort of outpatient febrile nonneutropenic pediatric oncology patients and to assess clinical characteristics that may influence decisions regarding empiric antibiotic therapy.

PROCEDURE

A single institution retrospective cohort study was performed of outpatient pediatric oncology patients presenting with fever, a central venous catheter, and an absolute neutrophil count (ANC) of >/=500/microl over a 6-year period. We also collected data regarding the presence of clinically evident infections, antibiotics prescribed, and the sensitivity of bacteria to specific antibiotics.

RESULTS

There were 29 cases of bacteremia in 459 (6.3%) febrile outpatient visits by 167 patients. Bacteremia was documented in 4.4% of patients with ports and in 16.2% of patients with external catheters. Patients with external catheters had a relative risk of bacteremia of 3.7 (95% CI: 1.8-7.4) times the risk of those with internal catheters (P < 0.0001). A documented source for fever on exam was noted in 21% of patients but in none of the patients with bacteremia (P = 0.004). Empiric treatment with ceftriaxone was administered to 92% of the patients. Of the high-risk bacteremic infections (Gram-negative organisms, Streptococcus pneumoniae, viridans group streptococcus, and Staphylococcus aureus) 94% had at least an intermediate sensitivity to ceftriaxone.

CONCLUSIONS

Bacteremia is an important issue in febrile nonneutropenic pediatric oncology patients occurring in 6% of the patient visits in this study. The overall sensitivity of high-risk bacteremia to ceftriaxone provides justification for its empiric use in outpatient febrile nonneutropenic pediatric oncology patients.

Etiology and clinical course of febrile neutropenia in children with cancer

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Infections in pediatric patients with hematologic malignancies

Despite significant advances in supportive care, infection remains second only to malignancy as a cause of death in pediatric oncology patients, and infection accounts for a large fraction of treatment-related costs. Multiple risk factors contribute to infection-related morbidity, chief among them the immunosuppressive effects of leukemia itself and of cytotoxic chemotherapy, prolonged hospitalization and antibiotic use, and loss of barrier integrity associated with mucositis and the need for indwelling central access. While viruses are the most common causes of infection, bacteria are responsible for most life-threatening complications. Gram-negative bacilli are a concern for all patients undergoing treatment, while a subset of gram-positive organisms, particularly viridans streptococci, become significant pathogens in children receiving profoundly immunosuppressive therapy. Invasive fungal infections are also a serious risk for morbidity and mortality in this population. Availability of new antimicrobial agents has made it possible to treat infectious complications more effectively, but their availability is also leading to an increased prevalence of highly resistant pathogens. Future work in pediatric oncology will need to include measures to reduce the immunosuppressive effects of anti-cancer therapy, provide targeted treatment for infections, and better identify groups of patients at high risk for infectious complications, who may benefit from antimicrobial prophylaxis or more aggressive empirical therapy.