Background: Pediatric hematology-oncology (PHO) and bone marrow transplantation (BMT) units have high use of antimicrobials. Objectives: To survey antimicrobials used in Greek PHO and BMT units before and after an intervention involving education on the 2017 clinical practice guidelines (CPG) for the management of febrile neutropenia in children with cancer and hematopoietic stem cell transplant recipients. Methods: Antibiotic prescribing practices were prospectively recorded between June 2016 and November 2017. In December 2017, education for the CPG took place and antibiotic prescribing practices were followed for one more year. For antibiotic stewardship, days of therapy and length of therapy were calculated. Results: Five of six PHO units and the single pediatric BMT unit covering >92% of children with hematologic and oncologic diseases in Greece participated. Administration of ≥ 4 antibiotics simultaneously and of antibiotics with overlapping activity for ≥ 2 days was significantly more common in PHO units located in general compared to pediatric hospitals. Use of at least one antifungal was recorded in approximately 47% of the patients before and after the intervention. De-escalation and/or discontinuation of antibiotics on day 6 of initial treatment increased significantly from 43% to 53.5% (p=0.032). Although the number of patients requiring support in the intensive care unit for sepsis did not change, a significant drop was noted in all-cause mortality after the intervention (p=0.008). Conclusion: Our surveillance was able to accurately document the antibiotic prescribing practices of Greek PHO and BMT units. Moreover, it identified areas in immediate need for improvement in antibiotic stewardship.

Immune Thrombocytopenia (ITP) is a relatively common hematologic disorder characterized by isolated thrombocytopenia. In children it is usually associated with a history of a preceding viral infection provoked by common viruses. During the pandemic of Coronavirus Disease-19(COVID-19) few cases have been described in literature associated with previous COVID-19 infection(1,2). We describe the case of a 2-year-old boy who presented with ITP which was attributed to previous COVID-19 infection based on positive serology and hence we aspire to highlight the importance of including Severe Acute Respiratory Syndrome Coronavirus-2(SARS-CoV-2) in routine serology tests performed in children with ITP during the current pandemic.

Objective: Τo investigate the association of serum vitamin D and nasal secretion antimicrobial peptides (AMPs) levels with the severity of acute bronchiolitis. Study design: We conducted a prospective single pediatric tertiary care center cohort study of inpatients aged 0-18 months with a first episode of acute bronchiolitis from November 1st 2014 to April 30th 2017. Disease severity was determined by the length of hospitalization and supplemental hospital data. Qualitative measurements included serum 25(OH)D and nasal secretion LL-37 and β-defensin-2 levels. Correlations were examined with the Mann-Whitney and Kruskal-Wallis criteria for qualitative and the correlation coefficient Spearman’s rho for quantitative factors. Multiple linear and logarithmic regression were performed in order to adjust for confounding factors. Results: The study population consisted of 153 infants and toddlers with mean age 3.6 months (SD: +2.8). The median level of serum 25(OH)D was 51.4 nmol/L (IQR: 29.7-72.2). No association was found between serum 25(OH)D and AMPs nasal secretions levels. Serum 25(OH)D and nasal secretion β-defensin-2 levels were not associated with the severity of bronchiolitis. In contrast, LL-37 levels were inversely associated with the length of hospitalization (rho = -0.340, p = 0.001) and the need for medication use (p = 0.001) and this association remained significant after adjustment for potential confounders. Conclusion: A significant association between LL-37 nasal secretions levels with the severity of acute bronchiolitis was found in hospitalized infants and toddlers. The role of LL-37 in the pathogenesis of bronchiolitis merits further investigation.