Although the proportion of Pseudomonas aeruginosa infections has reduced after the introduction of antibiotics with anti-pseudomonal effects, P. aeruginosa bacteremia still causes high mortality in immunocompromised patients. This study determined the clinical characteristics and outcomes of P. aeruginosa bacteremia and the antibiotic susceptibilities of strains isolated from febrile neutropenic patients. Thirty-one febrile neutropenic children and adolescents with underlying hematologic/oncologic disorders diagnosed with P. aeruginosa bacteremia between 2011 and 2016 were enrolled in the study. Their medical records were retrospectively reviewed to evaluate the demographic and clinical characteristics. Antibiotic susceptibility rates of the isolated P. aeruginosa to eight antibiotic categories (anti-pseudomonal penicillin, anti-pseudomonal penicillin and β-lactamase inhibitor combination, anti-pseudomonal cephalosporin, monobactam, carbapenem, aminoglycoside, fluoroquinolone, and colistin) were also determined. Among the investigated factors, risk factors for mortality and infections by a multidrug-resistance (MDR) strain were determined. Thirty-six episodes of P. aeruginosa bacteremia were identified. The mean age of the enrolled patients was 9.5 ± 5.4 years, and 26 (72.2%) episodes occurred in boys. Acute myeloid leukemia (41.7%) and acute lymphoblastic leukemia (33.3%) were the most common underlying disorders. The 30-day mortality was 38.9%, and 36.1% of the episodes were caused by MDR strains. The deceased patients were more likely to experience breakthrough infection (P = 0.036) and bacteremia (P = 0.005) due to MDR strains when compared with the patients who survived. The survived patients more likely received appropriate empirical antibiotic therapy (P = 0.024) and anti-pseudomonal β-lactam and aminoglycoside combination therapy (P = 0.039) compared with the deceased patients. The antibiotic susceptibility rates of the isolated P. aeruginosa strains were as follows: piperacillin/tazobactam, 67.6%; meropenem, 72.2%; and amikacin, 100%. Mortality due to P. aeruginosa bacteremia remained at 38.9% in this study, and more than one-third of the isolated strains were MDR. In this context, empirical antibiotic combination therapy to expand the antibiotic spectrum may be a strategy to reduce mortality due to P. aeruginosa bacteremia in febrile neutropenic patients.

The rate of urinary tract infections (UTIs) due to extended-spectrum β-lactamase (ESBL)-producing bacterial strains requiring carbapenem therapy has been increasing in children. This study was conducted to evaluate the effect of non-carbapenem antibiotic therapy on childhood UTIs caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae. Medical records of children diagnosed with febrile UTIs due to E. coli or K. pneumoniae between 2010 and 2014 were retrospectively reviewed. The enrolled children were divided into two groups: the ESBL group and the non-ESBL group. Clinical characteristics and therapeutic responses were compared between the two groups. A total of 211 episodes of UTI (204 caused by E. coli; seven caused by K. pneumoniae) were identified in 205 children. Twenty-two (10.4 %) episodes were categorized into the ESBL group. There was no significant difference in the type of antibiotic administered between the two groups. No carbapenems were administered; however, aminoglycosides were administered for 79.1 % of the total episodes. Although empirical antibiotics were appropriate for more episodes in the non-ESBL group compared with the ESBL group (100.0 % vs. 90.9 %, p = 0.011), there were no significant differences in the frequency of defervescence, bacterial eradication from the urine, acute pyelonephritis and vesicoureteral reflux or fever duration between the two groups. Non-carbapenem antibiotics showed favourable therapeutic effects on childhood UTIs caused by ESBL-producing strains. Aminoglycosides can be an alternative to carbapenems in such cases.

Febrile seizure (FS), which occurs in febrile children without underlying health problems, is the most common type of seizure disorder in children. The suggested pathogenesis of FS derived from several animal and human studies is multifactorial and debatable. Neuronal hyperexcitability, which develops during inflammatory responses that accompany fever, provokes seizures. However, the exact role of each inflammatory mediator (e.g., cytokines) is undefined in terms of the connection between systemic or local inflammation and the central nervous system, and the mechanisms by which cytokines increase neuronal excitability remain unclear. In contrast, the cause of fever in most children with FS is usually mild respiratory virus infection (e.g., rhinovirus, influenza virus, adenovirus, and enterovirus) rather than severe bacterial infections. In temperate regions, the major causative respiratory viruses seem to mirror seasonally prevalent respiratory viruses in the community. Therefore, vigorous efforts to identify the causative pathogen of fever may not be necessary in children with FS. Genetic factors seem to play a role in neuronal hyperexcitability, and some types of genetic variation have been identified in several genes encoding ion channels of neurons that participate in neuronal excitation. Although most children with FS have benign outcomes, some characteristics such as complex FS, febrile status epilepticus, consecutive afebrile seizures, and the presence of neurodevelopmental disabilities may require further genetic and neurologic evaluations.

Lee JH, et al. Infect Chemother. 2016 Sep;48(3):181-189. https://doi.org/10.3947/ic.2016.48.3.181

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.