Clinical Analysis of Acinetobacter Species Infections in Children and Adolescents Treated for Cancer or Undergoing Hematopoietic Cell Transplantation – a Multicenter Nationwide Study

Background: Acinetobacter, significantly A.baumannii, are becoming a great threat to hospitalized patients due to increasing antibiotic resistance. The aim of this study was to describe the epidemiology, clinical characteristic, antimicrobial susceptibility pattern and outcome of Acinetobacter infections in pediatric cancer patients and HSCT recipients in Poland. Methods: a total of 125 episodes of Acinetobacter species infections were reported in pa-tients < 18 years treated in Polish pediatric hematology and oncology centers over a pe-riod from 2012 to 2023. Infections were subdivided into oncohematological diseases (OHD) group (n=106; 84,8%) and hematopoietic stem cell transplant (HSCT) group (n=19; 15,2%). Results: A.baumannii is the most common Acinetobacter species in all groups. The most common diagnoses of infected patients in OHD group were: ALL (n=32; 30.2%) and AML (n=13; 12.3%). The most common underlying disease that was indication for HSCT among infected patients were hemophagocytic lymphohistiocytosis (n=3; 15.8%) and neuroblastoma (n=3; 15.8%). In OHD group, deaths did not correlate with the type of antibiotic, with an exception for gentamicin, which correlates with higher mortality. In HSCT group, deaths did not correlate with the type of antibiotic, except for levofloxa-cin that was correlated with higher mortality rate. Mortality was significantly higher in the HSCT group compared to the OHD group. Conclusions: Acinetobacter infections are a great danger to immunocompromised pa-tients. More research is needed in order to prevent and treat antibiotic resistant bacteria.