title: Changing trends in etiology of bacteremia in patients with cancer.
abstract: The present study was conducted to determine trends in the quantitative bacterial load patterns of bacterial bloodstream infections (BSI) caused by various bacteria in patients receiving care at a comprehensive cancer center. Bacterial loads of all consecutive quantitative blood cultures performed during 1998 and 2004 were graded quantitatively. Gram-positive bacteria (GPB) were responsible for the majority of BSI episodes in both years studied: 740 of 1,055 (73%) in 1998 and 820 of 1,025 (82%) in 2004. Compared with GPB infections, a significant proportion of infections caused by Gram-negative bacteria was associated with a high bacterial load (HBL) (11 vs 28% in 1998 and 10 vs 30% in 2004; p<0.001). In 2004, BSI episodes due to non-Pseudomonas non-fermentative GNB (Stenotrophomonas maltophilia and Acinetobacter spp) were significantly associated with a HBL compared to BSI due to Pseudomonas aeruginosa (47 vs 23%; p<0.05); this was not the case in 1998. Conversely, the HBLs commonly associated with BSI due to Staphylococcus aureus (50%) and Streptococcus spp (35%) versus coagulase-negative staphylococci (13%; p<0.0001) during 1998 were not noted during 2004 (22% Staphylococcus aureus, 20% Streptococcus spp, 21% coagulase-negative staphylococci; p>0.5). The spectrum of BSI continues to change and its prognostic implications in cancer patients needs further study.
authors.affiliation: Department of Infectious Diseases, Infection Control, and Employee Health, Unit 402, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA. asafdar@mdanderson.org
authors.forename: A
authors.initials: A
authors.lastname: Safdar
authors.forename: G H
authors.initials: GH
authors.lastname: Rodriguez
authors.forename: M
authors.initials: M
authors.lastname: Balakrishnan
authors.forename: J J
authors.initials: JJ
authors.lastname: Tarrand
authors.forename: K V I
authors.initials: KV
authors.lastname: Rolston
mesh_terms: D016470:Bacteremia / Q000209:etiology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D009369:Neoplasms / Q000150:complications*; D012189:Retrospective Studies