Infection 32 · 2004 · No. 2 © URBAN & VOGEL 65 Infection Clinical and Epidemiological Study Bloodstream Infections in Patients with Solid Tumors: Associated Factors, Microbial Spectrum and Outcome M. Anatoliotaki, V. Valatas, E. Mantadakis, H. Apostolakou, D. Mavroudis, V. Georgoulias, K.V. Rolston, D.P. Kontoyiannis, E. Galanakis, G. Samonis Abstract Background: Although patients with malignant diseases are at increased risk for bloodstream infections (BSIs), limited data are available for those with solid tumors. Patients and Methods: The etiology, clinical features and outcome of BSIs were retrospectively studied in patients with solid tumors treated at the Department of Medical Oncology at the University Hospital of Heraklion, Greece, from November 1995 through June 2000. Results: A total of 157 episodes of BSIs was identified among 137 patients over the study period. The majority of the episodes (128; 82%) occurred in non-neutropenic patients. 80 of 157 (51%) of the episodes were healthcare- associated, 35% (55 of 157) were nosocomial and 14% (22 of 157) were community acquired. A single pathogen was isolated in 86% of the episodes. A total of 184 pathogens was isolated (51% gram-negative rods, 44% gram-positive cocci, 3% anaerobes and 3% fungi), while the portal of entry was identified in 104 of 157 (66%) of the episodes. The site of the primary tumor or the metastases were the source of BSI in 39 of 104 (37.5%) of the episodes with an identified source. The overall infectious mortality was 20% and was significantly higher when the initial empirical antibiotic therapy was inappropriate (39%; p < 0.001) and in the presence of shock (63%; p < 0.001). Conclusion: BSIs in patients with solid tumors are frequently healthcare associated and in a large percentage the portal of entry can be identified. Neutropenia is not as common as in patients with hematologic malignancies. Inappropriate initial empirical antibiotic therapy and shock are clinical factors associated with worse outcomes. Infection 2004; 32: 65–71 DOI 10.1007/s15010-004-3049-5 Introduction Patients with cancer are at increased risk for bloodstream infections (BSIs), which are associated with considerable morbidity and mortality and a negative impact on the dose intensity of antineoplastic chemotherapy [1, 2, 3]. However, cancer patients do not comprise a homogeneous popula- tion, so that the predisposing factors, pathogens, clinical characteristics and outcome of BSIs may differ among cer- tain subsets of patients [4–6]. The available epidemiological data for BSIs in cancer patients are mainly derived from neutropenic patients with hematologic malignancies and bone-marrow transplant re- cipients [7–11]. In contrast, limited data on BSIs in patients with solid tumors exist [1, 12, 13]. In the current report, the authors describe the predisposing factors, clinical features, microbiological characteristics and outcome of BSIs exclu- sively in patients with solid tumors. Patients and Methods Inclusion Criteria Medical records of all patients cared for in the Department of Medical Oncology at the University Hospital of Heraklion, Crete, Greece, from November 1995 to June 2000 were retrospectively studied. Eligible cancer patients had a documented BSI defined as the isolation of a bacterial or fungal pathogen from at least one blood culture in the presence of clinical signs of infection. Our de- finition of BSI included any symptomatic bacteremia (presence of viable bacteria in the blood), in addition to sepsis and septic shock, as defined by the American College of Chest Physicians and the Society of Critical Care Medicine [14]. Sepsis was defined as a sys- temic inflammatory response associated with axillary temperature > 38 °C or < 36 °C, heart rate > 90 beats/min, respiratory rate > 20 breaths/min and a WBC count > 12,000/mm 3 or < 4,000/mm 3 or > 10% immature (band) forms in a patient with a positive blood culture. Septic shock was defined as sepsis with hypotension, de- spite adequate fluid resuscitation, along with the presence of per- fusion abnormalities, including but not limited to lactic acidosis, oliguria and mental status changes [14]. Since any given patient could have a BSI more than once, we used the term “episode of BSI” for each separate event. Patients who had major surgery and those with lymphomas were excluded. M. Anatoliotaki, V. Valatas, E. Mantadakis, H. Apostolakou, D. Mavroudis, V. Georgoulias ,E. Galanakis, G. Samonis (corresponding author) University General Hospital of Heraklion, Crete, Greece; University of Crete, Division of Medicine, P.O. Box 2208, Heraklion 71003, Crete, Greece; Phone (+30/2810) 392747, Fax: -392802, e-mail: georgsec@med.uoc.gr K.V. Rolston, D.P. Kontoyiannis Dept. of Medical Specialties, Section of Infectious Diseases, University of Texas M. D. Anderson Cancer Center, Houston, TX, USA Received: March 28, 2003 • Revision accepted: December 1, 2003