title: Clinical epidemiology of carbapenem-intermediate or -resistant Enterobacteriaceae.
abstract: OBJECTIVE
  Despite the increasing incidence of carbapenem-intermediate or -resistant Enterobacteriaceae (CIRE), risk factors associated with CIRE infections have not been well defined. This study characterizes factors associated with CIRE among two different source populations.
  
  
  METHODS
  A case-control study was performed at a tertiary care medical centre between January 2005 and December 2009. Cases were adults with a culture-confirmed Enterobacteriaceae infection with reduced susceptibility to meropenem or ertapenem. The CIRE cases were matched 1:1 to patients from two different control series: (i) those with carbapenem-susceptible Enterobacteriaceae (CSE) infections; and (ii) inpatients residing on the same ward within 30 days of CIRE culture date. Logistic regression was used to identify variables independently associated with CIRE among each source population. Restricted multivariate analyses were performed to determine if covariates predictive of CIRE varied by infecting organism or presence of the bla(KPC) gene.
  
  
  RESULTS
  There were 102 cases of CIRE during the study period. The only covariate independently associated with CIRE in all multivariate analyses was the cumulative number of prior antibiotic exposures. Compared with CSE controls, the odds ratios (95% confidence interval) were 1.43 (1.19-1.72), 2.05 (1.70-2.47) and 2.93 (2.43-3.53) for 1, 2 and ≥ 3 antibiotic exposures, respectively. The strength of this association was comparable for the hospitalized control group and analyses stratified by organism and presence of the bla(KPC) gene.
  
  
  CONCLUSIONS
  A patient's cumulative antibiotic exposure history is likely to be more important than any one specific exposure when determining the likelihood of developing a CIRE infection.
authors.affiliation: Pharmacy Practice Department, Albany College of Pharmacy and Health Sciences, Albany, NY 12208-3492, USA.
authors.forename: Nimish
authors.initials: N
authors.lastname: Patel
authors.forename: Susan
authors.initials: S
authors.lastname: Harrington
authors.forename: Amanda
authors.initials: A
authors.lastname: Dihmess
authors.forename: Benjamin
authors.initials: B
authors.lastname: Woo
authors.forename: Rasha
authors.initials: R
authors.lastname: Masoud
authors.forename: Pearl
authors.initials: P
authors.lastname: Martis
authors.forename: Mallory
authors.initials: M
authors.lastname: Fiorenza
authors.forename: Eileen
authors.initials: E
authors.lastname: Graffunder
authors.forename: Ann
authors.initials: A
authors.lastname: Evans
authors.forename: Louise-Anne
authors.initials: LA
authors.lastname: McNutt
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Lodise
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D015780:Carbapenems / Q000494:pharmacology* / Q000627:therapeutic use*; D016022:Case-Control Studies; D004363:Drug Utilization / Q000706:statistics & numerical data; D004755:Enterobacteriaceae / Q000187:drug effects* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D000077727:Ertapenem; D005260:Female; D006801:Humans; D008297:Male; D000077731:Meropenem; D008875:Middle Aged; D012307:Risk Factors; D013845:Thienamycins / Q000494:pharmacology / Q000627:therapeutic use; D018440:beta-Lactam Resistance; D047090:beta-Lactams / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D013845:Thienamycins; D047090:beta-Lactams; D000077731:Meropenem; D000077727:Ertapenem