The evaluation of healthcare-associated infections in patients with hematologic malignancies

Introduction and Aim: Healthcare-associated infections (HAIs) in patients with hematologic malignancies are a significant cause of morbidity and mortality, adversely affecting treatment outcomes. This study aimed to evaluate the types of HAIs, causative microorganisms, antimicrobial resistance profiles, and mortality-related factors in patients diagnosed with hematologic malignancies. Materials and Methods: A total of 182 adult patients diagnosed with HAIs between January 1, 2019, and October 10, 2024, at Dicle University Faculty of Medicine Hospital were retrospectively analyzed. Data were evaluated using SPSS version 27.0. Results: 48.4% of the patients were diagnosed with Acute Myeloid Leukemia (AML); the mean duration of neutropenia was 10.5 days, and the mortality rate was determined to be 35.2%. The most common types of healthcare-associated infections (HAIs) were Laboratory-Confirmed Bloodstream Infection (LC-BSI) type 1 (35.7%), Central Line-Associated Bloodstream Infection (CLABSI) (23.1%), and Mucosal Barrier Injury–Laboratory-Confirmed Bloodstream Infection (MBI-LC-BSI) type 1 (18.1%), which together accounted for 77% of all infections. The most prevalent pathogens were Escherichia coli (43.1%) and Klebsiella pneumoniae (29.9%); 81% of the pathogens were gram-negative bacteria. The most common resistance pattern was Carbapenem-Resistant Enterobacteriaceae (CRE) plus Extended-Spectrum Beta-Lactamase (ESBL) production, identified in 44.4% of isolates. Meropenem (52.2%) was the most frequently used empirical antibiotic, whereas colistin (18.6%) was the most commonly administered agent after culture results. A statistically significant association was found between the duration of neutropenia and mortality (p = 0.028); each additional day of neutropenia increased the risk of death by 4.6%. No significant relationship was found between absolute neutrophil count and mortality. Mortality rates were notably higher in cases of CLABSI and LC-BSI type 1, while patients with MBI-LC-BSI type 1 had better survival outcomes. No statistically significant association was observed between the type of malignancy and mortality. Conclusion:HAIs represent a serious infectious burden in patients with hematologic malignancies. Resistant gram-negative pathogens and prolonged neutropenia are key contributors to mortality. Strict infection control measures, culture-guided therapy, and the use of antibiotics based on local resistance patterns are essential to improve outcomes in this vulnerable patient population. Keywords: Hematologic Neoplasms, Healthcare-Associated Infections, Neutropenia, Drug Resistance, Mortality