Emergence of multidrug resistant isolates and mortality predictors in patients with solid tumors or hematological malignancies.

Introduction: Infections are an important preventable cause of death in cancer patients. The aim of this study was to clarify the epidemiologic characteristics and resistance patterns of causative isolates and mortality predictors in infections of cancer patients.

Methodology: Patients with sterile site infections were evaluated in a retrospective cohort study. Etiological agents, antimicrobial resistance patterns of the isolates, and possible risk factors for mortality were recorded. Survivors and non-survivors on day 30 after each infection onset were compared to identify the predictors of mortality.

Results: A total of 205 infection episodes of 132 patients were included in this study. Of them, 75% had hematologic malignancies and 25% had solid tumors. Febrile neutropenia was diagnosed in 61.5%. Bloodstream infections were the most frequent infection (78%). The majority of the pathogens were Enterobacteriaceae (44.3%) and nonfermentative isolates (17.6%). Multidrug-resistant (MDR) infections were responsible for 40% of the episodes. The mortality rate was 23.4%. Inadequate initial antibiotic treatment (OR = 4.04, 95% CI = 1.80-9.05, p = 0.001), prolonged neutropenia (> 7 days) before infection (OR = 3.61, 95% CI = 1.48-8.80, p = 0.005), infection due to Klebsiella species (OR = 3.75, 95% CI = 1.31-10.7, p = 0.013), and Acinetobacter baumannii (OR = 5.00, 95% CI = 1.38-18.2, p = 0.014) were independent predictors of mortality.

Conclusions: Gram-negative isolates were found to be the predominant pathogens with higher mortality rates. Local epidemiological data should be taken into account when administering empirical therapy since the inadequacy of initial antibiotherapy is associated with a poor outcome.