title: Limits of patient isolation measures to control extended-spectrum beta-lactamase-producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward.
abstract: BACKGROUND
  Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are a growing concern in hospitals and the community. How to control the nosocomial ESBL-E transmission is a matter of debate. Contact isolation of patients has been recommended but evidence supporting it in non-outbreak settings has been inconclusive.
  
  
  METHODS
  We used stochastic transmission models to analyze retrospective observational data from a two-phase intervention in a pediatric ward, successively implementing single-room isolation and patient cohorting in an isolation ward, combined with active ESBL-E screening.
  
  
  RESULTS
  For both periods, model estimates suggested reduced transmission from isolated/cohorted patients. However, most of the incidence originated from sporadic sources (i.e. independent of cross-transmission), unaffected by the isolation measures. When sporadic sources are high, our model predicted that even substantial efforts to prevent transmission from carriers would have limited impact on ESBL-E rates.
  
  
  CONCLUSIONS
  Our results provide evidence that, considering the importance of sporadic acquisition, e.g. endogenous selection of resistant strains following antibiotic treatment, contact-isolation measures alone might not suffice to control ESBL-E. They also support the view that estimating cross-transmission extent is key to predicting the relative success of contact-isolation measures. Mathematical models could prove useful for those estimations and guide decisions concerning the most effective control strategy.
authors.affiliation: Unité de Pharmacoépidémiologie et Maladies Infectieuses, Institut Pasteur, Paris, France. domenech@pasteur.fr
authors.forename: Matthieu
authors.initials: M
authors.lastname: Domenech de Cellès
authors.forename: Jean-Ralph
authors.initials: JR
authors.lastname: Zahar
authors.forename: Véronique
authors.initials: V
authors.lastname: Abadie
authors.forename: Didier
authors.initials: D
authors.lastname: Guillemot
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D004755:Enterobacteriaceae / Q000201:enzymology* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology / Q000517:prevention & control* / Q000635:transmission; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008962:Models, Theoretical; D010356:Patient Isolation; D010372:Pediatrics; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D001618:beta-Lactamases