Factors associated with mortality in bacteremic patients with hematologic malignancies Mario Tumbarello a, ⁎ , Teresa Spanu b , Morena Caira c , Enrico M. Trecarichi a , Luca Laurenti c , Eva Montuori a , Luana Fianchi c , Fiammetta Leone b , Giovanni Fadda b , Roberto Cauda a , Livio Pagano c a Institute of Infectious Diseases, Catholic University of the Sacred Heart, Largo A. Gemelli 8, 00168 Rome, Italy b Institute of Microbiology, Catholic University of the Sacred Heart, Largo A. Gemelli 8, 00168 Rome, Italy c Institute of Hematology, Catholic University of the Sacred Heart, Largo A. Gemelli 8, 00168 Rome, Italy Received 9 June 2008; accepted 17 February 2009 Abstract We conducted a retrospective cohort study to identify risk factors for mortality in a large cohort of hematologic patients with bacteremia. From 2000 through 2005, bacteremia was diagnosed in 217 patients with hematologic malignancies. The infections were caused only by Gram-positive organisms in 57.1% (124/217) cases and only by Gram-negative bacteria in 37.8% (82/217); the remaining 5.1% (11/217) were polymicrobial. The overall 30-day mortality rate was 20.3% (44/217). In multivariate analysis, significant predictors of mortality were prolonged neutropenia (P b 0.001), acute renal failure (P = 0.002), nosocomial bacteremia (P = 0.009), age N55 years (P = 0.007), and monomicrobial bacteremia due to antibiotic-resistant Gram-negative bacteria (P = 0.009). Reducing fatal outcomes associated with bacteremia in patients with hematologic malignancies is a challenge, and the emergence of resistance to the antimicrobials widely used in this setting is of great concern. Future infection trends must be carefully monitored and treatment guidelines adjusted accordingly. © 2009 Elsevier Inc. All rights reserved. Keywords: Bacteremia; Hematologic malignancies; Mortality; Antimicrobial resistance 1. Introduction New forms of treatment and more aggressive supportive care have recently improved the prognosis of patients with hematologic malignancies. However, this progress has been accompanied by increases in the risk of severe infections owing to the more profound immunosuppression caused by treatment, increases in the frequency of mucositis (which often reaches debilitating levels), and the extensive use of invasive diagnostic and therapeutic procedures, for example, insertion of central venous catheters (Wisplinghoff et al., 2003b). Bloodstream infections are among the most common infectious complications observed in patients with hemato- logic malignancies with a prevalence that ranges from 11% to 38% (Gaytán-Martínez et al., 2000; Klastersky, 1998; Madani, 2000; Serody, 2000). Crude mortality rates vary from 12% to 42%, and attributable mortality rates as high as 30% have emerged from some studies (Collin et al., 2001; Gaytán-Martínez et al., 2000; Klastersky, 1998; Krupova et al., 1998; Madani, 2000; Serody, 2000). The prevention and management of these infections have also improved progressively in recent years. Clinical practice guidelines published by the Infectious Diseases Society of America recommend the prompt administration of empiric broad- spectrum antibacterial therapy for the management of high- risk febrile neutropenic patients with cancer (Hughes et al., 2002; Rolston, 2004). The extended-spectrum cephalospor- ins (cefepime or ceftazidime), carbapenems (imipenem or meropenem), and the antipseudomonal penicillins (piper- acillin–tazobactam or ticarcillin–clavulanate) are the main- stay of empiric monotherapy or combination therapy for such patients (Hughes et al., 2002; Rolston, 2004). However, in many institutions (including our own), in vitro resistance Available online at www.sciencedirect.com Diagnostic Microbiology and Infectious Disease 64 (2009) 320 – 326 www.elsevier.com/locate/diagmicrobio ⁎ Corresponding author. Istituto Malattie Infettive, Università Cattolica, Largo A. Gemelli 8, 00168 Roma, Italy. Tel.: +39-06-30155373; fax: +39- 06-3054519. E-mail address: tumbarello@rm.unicatt.it (M. Tumbarello). 0732-8893/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.diagmicrobio.2009.02.008