Clinical Analysis of Species Infections in Children and Adolescents Treated for Cancer or Undergoing Hematopoietic Cell Transplantation: A Multicenter Nationwide Study.

: , specifically , are becoming a great threat to hospitalized patients due to increasing antibiotic resistance. The aim of this study was to describe the epidemiology, clinical characteristics, antimicrobial susceptibility pattern and outcome of infections in pediatric cancer patients and hematopoietic stem cell transplant (HSCT) recipients in Poland. : A total of 125 episodes of species infections were reported in patients <18 years treated in Polish pediatric hematology and oncology centers over a period from 2012 to 2023. Infections were subdivided into oncohematological disease (OHD) group ( = 106; 84.8%) and HSCT group ( = 19; 15.2%). Each episode represented a separate infection event; therefore, a patient who was infected more than once during the course of treatment was counted for each infection episode. : is the most common species in all groups. The most common diagnoses in OHD group were acute lymphoblastic leukemia (ALL) ( = 32; 30.2%) and acute myeloid leukemia (AML) ( = 13; 12.3%). The most common underlying diseases that were indication for HSCT were hemophagocytic lymphohistiocytosis ( = 3; 15.8%) and neuroblastoma ( = 3; 15.8%). Mortality was significantly higher in the HSCT group compared to the OHD group. In the OHD group, deaths did not correlate with the type of antibiotic, with an exception for gentamicin, which correlated with higher mortality. In the HSCT group, deaths did not correlate with the type of antibiotic, except for levofloxacin that was correlated with a higher mortality rate. : infections are a great danger to immunocompromised patients. More research is needed in order to prevent and treat antibiotic-resistant bacteria.