Ten-year surveillance of nosocomial bloodstream infections: trends of aetiology and antimicrobial resistance in a comprehensive cancer centre

摘要

Background:Bloodstream infections (BSIs) are one of the major life -threatening infectious conditions in cancer patients and are respon-sible for prolonge d ho spital stays, high healthcare costs and significant mortality. Several clinical trials have reported an improved survival in patients treate d with appropriate empirical broad-spectrum antibiotic therapy. Early detection of path ogens and determination of their susceptibility are e ssential fo r the optimization of treatment. Variability between hospitals is substantial and requires the individual analy-sis of local trends. The aim of this study is to assess the local epidemio lo gy of BSI in a single cancer centre over a 10 -year period.Methods:Retrospective microbiological surveillance of all febrile/infective episodes occurring in oncological and surgical patients in a high -volume cancer centre between January 1999 and December 20 08 were considered. Patients' data were collected, proce ssed and analyzed using the epidemiological resource of the Virtuoso Plus software (Metafora Informatica Srl, Milano, Italy). Spearman's rank correlation coefficient, including the two -taile d test of significance, was used to investig ate trends of incidence and rate of antibiotic resist-ance over the 10-year period.Results:A total of 13,058 blood cultures (BCs) were p erformed in 2,976 patients. BCs were positive in 2,447 tests, representing 740 infec-tive/febrile episodes: 358 (48%) in medica l oncology and 382 (52%) in surgical wards. Gram-p ositives were responsible for the majority of episodes in o ncological and surgical divisions (about 6 3% and 55%, respectively). Gram-positives were also the most common orga nism in n on-catheter-related BSIs (CRBSIs) both in medical o ncology (75%) and in surgical divisions (50%). Enterococcishowed an increased resistance to levofloxacin, from 5.6% to 25.7% (p= 0.02) and to erythromycin, from 41.7% to 61.4%, (p= 0.0 5). Similarly, co agulase nega-tive staphylococci (CoNS) developed resistance to levofloxacin and ciprofloxacin, passing from 3 3.9% to 67.4% (p= 0.01) and from 5.6% to 25.7% (p= 0.01), respectively.Conclusions:Gram-po sitives are the main pathog ens of BSIs; there is no difference in aetiology of CRBSIs between surgical and onco-logical patients. The lower incidence of gram-positive non-CRBSIs in surgical patients was probably due to gram-negative infections secondary to surgical complications