The frequency, epidemiology and risk factors of bloodstream infections in febrile neutropenic patients with hematologic malignancies

Bacteremia is considered as the most significant cause of mortality and morbidity in febrile neutropenic patients. The epidemiology and risk factors might differ among institutions and over the time period. The aim of this study is to evaluate the frequency, epidemiology and factors predictive of bacteremia in neutropenic patients in Gazi University Faculty of Medicine Hematology and Hematopoietic Stem Cell Transplantation (HSCT) clinics between November 2007 and November 2008.177 febrile neutropenic episodes of 115 patients with hematological malignancies were included in this study. Cases were defined as patients with bloodstream infection and controls were the patients without bloodstream infections. We evaluated the cases and controls for the risk factors, complications and mortality rates. Microorganisms isolated from blood samples and their susceptibility patterns were also analysed.The prevalence of bacteremia was 61%, 42,6% of them were catheter related and mortality rate was 12,4%. Bloodstream infections are more common in the patients with uncontrolled underlying disease and long term severe neutropenia.Duration of severe neutropenia (neutrophile count <100/ mm3), underlying hematologic malignancy, stem cell transplantation, relapsing or refractory disease, presence of central venous catheter and presence of mucositis were significant predictive factors for bacteremia. Presence of central venous catheter and relapsing or refractory disease were independent risk factors. The incidence of hypotension and intensive care necessity were higher in cases. Candidemia and gram negative bacteremia were significantly associated with higher mortality rates.Gram-positive microorganisms were the most common isolates ( 76,8%) with the predominance of coagulase negative staphylococci (63,6%) with methicillin resistance rate of 64%. For S.aureus isolates meticillin resistance rate was 25%.The most frequent gram-negative pathogen was E.coli with extremely high quinolon resistance rate of 82,1% and the resistance rate of 3.-4. generation cephalosporins was 50%.In conclusion, monitorization for the epidemiology of bacteremia and prediction of significant factors associated with bacteremia in febrile neutropenic patients are considered to be important for the choice of initial antibiotic therapy.Key words: Febrile neutropenia, bloodstream infection, risk factors.