National study reveals gram negative bacteremia on contemporary pediatric AML protocol.

Since bacteremia complicates childhood Acute myeloid leukemia (AML) patients, we assessed bacteremia rates in Israeli children with de-novo AML. All chemotherapy courses of patients enrolled in NOPHO-DBH-2012 AML protocol were included. Down syndrome, acute promyelocytic leukemia were excluded. Among 69 patients, seven had focal bacterial infections. Of the remaining 62, 77.4% had 1-8 bacteremias. Of 238 chemotherapy courses, 98 (41.2%) had bacteremia: 66 (67.3%) predominantly Gram-negative rods (GNR); 28 (28.6%) Gram-positive cocci. Escherichia coli; followed by Klebsiella were most common. Older age, Arab ethnicity, and presenting white blood cell count were associated with an increased risk of bacteremia in the univariable analysis, but these associations were not confirmed in the multivariable analysis. Mortality was high (9.7%), and bacteremia increased PICU utilization 7-fold half from GNR. Most isolates were sensitive to vancomycin/meropenem (94.7%), but GNR had low sensitivity to quinolones (61.8%). High mortality and morbidity of de-novo AML patients from predominantly GNR bacteremia require specific interventions but limited susceptibility to quinolones hampers prophylaxis.

Incidence, Predictors, and Outcomes of Pseudomonas aeruginosa Associated Acute Appendicitis in Children.

BACKGROUND: Pseudomonas aeruginosa (PSA) is an infectious pathogen associated with acute appendicitis; however, it is not consistently addressed by empirical antibiotic therapy, despite potential complications. OBJECTIVES: To investigate the incidence, predictors, and outcomes of PSA-associated acute appendicitis in children. METHODS: We conducted a retrospective analysis involving pediatric patients who underwent acute appendicitis surgery and had positive peritoneal cultures. Clinical, microbiological, and intraoperative data were extracted from medical records. RESULTS: Among 2523 children with acute appendicitis, 798 (31.6%) underwent peritoneal cultures, revealing 338 positive cases (42.3%), with PSA detected in 77 cases (22.8%). Children with PSA were three times more likely to exhibit high intraoperative grading ≥ 3 (93.4% vs. 76.8%, 95% confidence interval [95%CI] 1.2-8.3, P = 0.023) and nearly four times more likely to have polymicrobial cultures (88.3% vs. 62.1%, 95%CI 1.8-8.0, P < 0.001) than those without PSA in peritoneal cultures. Duration of symptoms did not predict PSA isolation (P = 0.827). Patients with PSA had longer median hospital stays (8 days, interquartile range [IQR] 7-10) than those with other pathogens (7 days, IQR 5-9) (P = 0.004). Antibiotic treatment duration, intensive care unit admission rates, readmission, and mortality were similar between the two groups (P = 0.893, 0.197, 0.760, and 0.761, respectively). CONCLUSIONS: PSA is a common pathogen in children diagnosed with acute appendicitis and positive peritoneal cultures. The likelihood of isolating PSA increases with high-grade intraoperative assessment and in the presence of multiple pathogens in peritoneal cultures, suggests antipseudomonal treatment.

Pseudomonas Bacteremia in Children: Clinical and Microbiologic Features and Risk Factors of Mortality: A Retrospective Cohort Study.

BACKGROUND: Pseudomonas bacteremia is most commonly acquired in hospital. The aim of this study was to investigate the clinical features and antibiotic susceptibility, mortality rate and risk factors of mortality in children with Pseudomonas bacteremia. METHODS: A retrospective cohort study that included children 18 years of age or younger admitted to a tertiary hospital with Pseudomonas bacteremia between 2005 and 2020. RESULTS: A total of 196 patients with Pseudomonas bacteremia were identified. The proportional rate of Pseudomonas bacteremia was 33.9/100,000 hospital days. Underlying disease was documented in 81.1% of patients, 61% had hemato-oncological disease. Pseudomonas bacteremia was healthcare related in 180 (91.8%) episodes. Multidrug-resistant (MDR) Pseudomonas accounted for 16 (8.2%) and difficult-to-treat organism to 3 (1.5%) of all isolates. Thirty-day mortality was reported in 27 (13.8%) patients, all had Pseudomonas aeruginosa . In multivariate regression analysis, the first model showed that younger age [ P = 0.038, odds ratio (OR) = 1.095, 95% confidence interval (CI): 1.005-1.192] and inappropriate empiric antibiotic treatment ( P = 0.004, OR = 3.584, 95% CI: 1.490-8.621) were significantly associated with higher mortality. The second model also showed higher morality in younger age ( P = 0.021, OR = 1.114, 95% CI: 1.016-1.221) and MDR isolates ( P = 0.001, OR = 9.725, 95% CI: 2.486-38.039). CONCLUSIONS: Significant morbidity and mortality due to Pseudomonas bacteremia, but relatively lower mortality than previously published. Although young age, MDR isolates and inappropriate antibiotic treatment have been associated with increased mortality, these factors, especially with low prevalence of MDR isolates, may reflect the baseline mortality rate in vulnerable hosts with continuous contact with healthcare facilities facing such severe infection, and more efforts should be made to emphasize infection control practices to prevent such severe infection.

Third BNT162b2 Vaccine Booster Dose against SARS-CoV-2-Induced Antibody Response among Healthcare Workers.

This study assessed humoral response to the third BNT162b2 dose among healthcare workers (HCW). This prospective cohort study of HCW tested for anti-spike antibodies (LIAISON SARS-CoV-2 S1/S2 IgG assay) at 1, 3, 6, 9, and 12 months after receiving the second BNT162b2 vaccine dose (tests 1, 2, 3, 4, and 5, respectively). A third (booster) vaccination dose was introduced before test 4. Linear regression model was used to determine the humoral response following vaccine doses. For each serology test, changes in log-transformed antibody concentrations over time, adjusted for age, sex, underlying diseases, steroid treatment, and smoking were described using the general linear mix model. Serology tests were performed at 3, 6, 9, and 12 months after the second vaccine dose in 1113, 1058, 986, and 939 participants, respectively. The third dose was received by 964 participants before the 9-month tests, 797 of whom participated in the 9- and 12-month serology tests. A significant inverse correlation was noted between time from third dose and antibody concentrations (Spearman correlation −0.395; p < 0.001). Age (p < 0.0001; CI 95% −0.005−−0.004), heart disease (p < 0.0001; CI 95% −0.177−−0.052), immunodeficiency (p < 0.0001; CI 95% 0.251−−0.106), and smoking (p < 0.0001; CI 95% −0.122−−0.040) were significantly associated with decreased antibody concentrations. Female sex (p = 0.03; CI 95% 0.013−0.066) was associated with increased antibody concentrations. The third booster dose had a better effect on immunogenicity, with higher antibody concentrations among tested HCW. Heart disease, smoking, and other known risk factors were associated with decreased antibody concentrations.

NonTuberculous Mycobacteria Blood Stream Infection in Pediatric and Adult Patients: 15 Years Surveillance.

BACKGROUND: Nontuberculous Mycobacteria (NTM) are rare causes of bloodstream infection (BSI). This study addresses the management and prognosis of NTM BSI and the differences between adult and pediatric patients. METHODS: We retrospectively reviewed the medical charts of patients at any age with NTM BSI, from January 1, 2005, to June 30, 2020. Data on demographics, underlying conditions, clinical manifestations, NTM species, antibiotic treatments and outcomes were retrieved. RESULTS: Positive blood cultures for NTM were detected in 43 patients, 30 children and 13 adults. Median age: 10.37 years (IQR 6.692-39.864). Thirty-seven (86%) patients had an active malignant disease. Fever was the chief sign in 23 (53.5%) patients and pulmonary manifestations in 14 (32.6%). Rapidly growing NTM comprised 39 (90.7%) of the isolates. Central venous catheter (CVC) was documented in 39 (90.7%) cases, 31 (79.5%) of which were removed as part of treatment. Antibiotic treatment directed against NTM was documented in 26 (60.5%) patients. CVC was removed in 7/17 patients who were not treated with antibiotics. Relapse occurred in 3 cases; no 30-days mortality was reported. Children and adults had similar clinical characteristics. However, children had a higher rate of CVC at the time of bacteremia and a higher chance to receive treatment. CONCLUSION: NTM BSI was seen mainly in oncologic patients with CVC. Children and adults had a similar disease course and outcome. Relapse was rare and NTM-related mortality was not reported.

The epidemiology of Staphylococcus aureus bacteraemia in Israeli children: Community- vs hospital-acquired or healthcare related infections.

AIM: Incidences of Staphylococcus aureus bacteraemia (SAB) in Israeli children are unknown. The characteristics of SAB in children have not been evaluated. METHODS: SAB from children aged ≤18 years old, admitted to a tertiary hospital in Israel during 2002-2015, were included. The proportional rate of SAB was calculated per 1000 admissions. SAB were classified as community acquired (CA), hospital acquired (HA) and healthcare related (HCR). Patients' characteristics, antibiotic susceptibility and outcomes were assessed in each group. RESULTS: The rate of SAB was stable, 1.48 per 1000 admissions. HA, CA and HCR-SAB comprised 53%, 25% and 22%, respectively. Only 27/185 (14.6%) were caused by methicillin-resistant S aureus (MRSA): 22%, 6% and 5% of HA, CA and HCR-SAB, respectively. Central venous catheter, recent surgery, immunodeficiency and age <6 years were the main risk factors for HA and HCR-SAB (adjusted OR: 68.9, 7.5, 5.8 and 5.5, respectively). Treatment duration for CA was >21 days: and for HA and HCR, 14-20 days. All-cause in-hospital mortality and 30-day mortality were documented in 10 (5%) and 3 (2%) episodes, respectively. CONCLUSION: The rate of SAB; the proportions of CA, HA and HCR-SAB; and the proportion of MRSA was stable over the years. MRSA was mainly in HA-SAB. Thirty-day mortality was rare.

Q Fever Osteoarticular Infection in Children.

Q fever osteoarticular infection in children is an underestimated disease. We report 3 cases of Q fever osteomyelitis in children and review all cases reported in the literature through March 2018. A high index of suspicion is encouraged in cases of an unusual manifestation, prolonged course, relapsing symptoms, nonresolving or slowly resolving osteomyelitis, culture-negative osteomyelitis, or bone histopathology demonstrating granulomatous changes. Urban residence or lack of direct exposure to animals does not rule out infection. Diagnosis usually requires use of newer diagnostic modalities. Optimal antimicrobial therapy has not been well established; some case-patients may improve spontaneously or during treatment with a ß-lactam. The etiology of treatment failure and relapse is not well understood, and tools for follow-up are lacking. Clinicians should be aware of these infections in children to guide optimal treatment, including choice of antimicrobial drugs, duration of therapy, and methods of monitoring response to treatment..

Kingella Kingae Chest Mass Mimicking a Tumor in an 11-Month-Old Baby.

Kingella kingae has been recognized as a common etiology of pediatric osteoarticular infections, especially among children younger than 5 years of age. In recent years, there have been reported cases of unusual manifestations. We report a rare case of a chest mass mimicking a tumor in an 11-month-old baby.