Limits of patient isolation measures to control extended-spectrum beta-lactamase–producing Enterobacteriaceae: model-based analysis of clinical data in a pediatric ward
1 Unité de Pharmacoépidémiologie et Maladies Infectieuses, Institut Pasteur, Paris, France
2 U657, Inserm, Paris, France
3 Paris 6: Univ. Pierre et Marie Curie, Cellule Pasteur UPMC, Paris, France
4 Unité d’hygiène hospitalière, Service de microbiologie, CHU Necker-Enfants Malades, Paris, France
5 Université Paris Descartes, Paris, France
6 Service de Pédiatrie générale, CHU Necker-Enfants Malades, Paris, France
7 EA 4499, Université de Versailles–Saint-Quentin-en-Yvelines, Versailles, France
8 Unité Fonctionnelle de Santé Publique, Hôpital Raymond-Poincaré, Assistance Publique–Hôpitaux de Paris, Garches, France
BMC Infectious Diseases 2013, 13:187 doi:10.1186/1471-2334-13-187Published: 24 April 2013
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.
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.
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.
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.