Infections in Children with Acute Lymphoblastic Leukemia

<i>Background and Objectives:</i> Infections are the most common and potentially life-threatening complications of the treatment of children with acute lymphoblastic leukemia (ALL). The aim of this study was to determine epidemiological, clinical, and microbiological characteristics of infections in pediatric patients with ALL. <i>Materials and Methods:</i> Twenty-three children (16 males and 7 females, with a mean age of 5.9 years (range of 1.3 to 12.2 years)) with ALL, treated at the Division of Hematology, Oncology, and Clinical Genetics, Department of Pediatrics, Clinical Hospital Center Rijeka, Croatia, from 1 January 2015 to 31 December 2020, were included in the study. <i>Results:</i> One hundred and four infectious episodes (IEs) were reported (an average of 4.5 IE per patient). IEs were more frequent in the intensive phases of antileukemic treatment. Neutropenia was present in 48 IEs (46.2%) with a duration greater than 7 days in 28 IEs (58.3%). The respiratory tract was the most common infection site (48.1%). We documented 49 bacterial (47.1%), 4 viral (3.9%), 4 fungal (3.9%), and 10 mixed isolates (9.6%), while in 37 IEs (35.6%), a pathogen was not isolated. The most common causes of bacteremia were coagulase-positive staphylococci. The most frequent empirical therapy was third- and fourth-generation cephalosporins, followed by piperacillin/tazobactam. The modification of first-line antimicrobial therapy was performed in 56.9% of IEs. Granulocyte-colony stimulating factor was administered in 53.8% of IEs, and intravenous immunoglobulins were administered in 62.5% of IEs. One patient required admission to the intensive care unit. No infection-related mortality was reported. <i>Conclusions:</i> ALL patients have frequent IEs. Close monitoring, the identification of risk factors, the rapid empirical use of antibiotics in febrile neutropenia, and the timely modification of antimicrobial therapy play key roles in reducing infection-related morbidity and mortality in children with ALL.