title: [Mortality caused by bacteremia Escherichia coli and Klebsiella spp. extended-spectrum beta-lactamase- producers: a retrospective cohort from a hospital in Lima, Peru].
abstract: OBJECTIVE
  To evaluate the factors associated to mortality caused by bacteremia due to Escherichia coli and Klebsiella spp. producers of extended-spectrum beta-lactamase (ESBL).
  
  
  METHODS
  We performed a retrospective cohort study, including 85 patients older than 16 and diagnosed with bacteremia by Escherichia coli or Klebsiella spp., hospitalized between 2006 and 2008 in Cayetano Heredia National Hospital. Cohorts were classified according to the ESBL production following blood culture results. Factors associated to gross and attributable mortality were evaluated using the Poisson regression in a multivariate model, through which adjusted relative risks (ARRs) were obtained. Mortality curves were also built.
  
  
  RESULTS
  35.3% of bacteremia cases were caused by ESBL-producing strains. The analysis of gross mortality showed a higher mortality rate in the group with ESBL producing strains (63.3%), ARR being 1.5 (CI 95%: 1.02-2.3). In the case of the attributable mortality, the proportion was also higher (63.3%), ARR being 1.9 (CI 95%: 1.2-2.9). The use of a central venous catheter was another factor associated to both gross mortality (ARR= 2.4; CI 95%: 1.2-4.8) and attributable mortality (ARR= 3.8; CI 95%: 1.6-8.8).
  
  
  CONCLUSIONS
  The production of ESBL is an independent risk factor for bacteremia mortality caused by E. coli and Klebsiella spp. Its presence should be evaluated following diagnosis consideration and initial therapy elaboration, which could in turn decrease the mortality by this cause.
authors.affiliation: Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Perú. diego.adrianzen@upch.pe
authors.forename: Diego
authors.initials: D
authors.lastname: Adrianzén
authors.forename: Angela
authors.initials: A
authors.lastname: Arbizu
authors.forename: Jimmy
authors.initials: J
authors.lastname: Ortiz
authors.forename: Frine
authors.initials: F
authors.lastname: Samalvides
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000401:mortality*; D015331:Cohort Studies; D004756:Enterobacteriaceae Infections / Q000401:mortality*; D004926:Escherichia coli / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000401:mortality*; D005260:Female; D006801:Humans; D007709:Klebsiella / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D010568:Peru / Q000453:epidemiology; D012189:Retrospective Studies; D055815:Young Adult; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D001618:beta-Lactamases