Quantifying Hospital-Acquired Carriage of Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae Among Patients in Dutch Hospitals

Abstract

BACKGROUND Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are emerging worldwide. Contact precautions are recommended for known ESBL-E carriers to control the spread of ESBL-E within hospitals. OBJECTIVE This study quantified the acquisition of ESBL-E rectal carriage among patients in Dutch hospitals, given the application of contact precautions. METHODS Data were used from 2 cluster-randomized studies on isolation strategies for ESBL-E: (1) the SoM study, performed in 14 Dutch hospitals from 2011 through 2014 and (2) the R-GNOSIS study, for which data were limited to those collected in a Dutch hospital in 2014. Perianal cultures were obtained, either during ward-based prevalence surveys (SoM), or at admission and twice weekly thereafter (R-GNOSIS). In both studies, contact precautions were applied to all known ESBL-E carriers. Estimates for acquisition of ESBL-E were based on the results of admission and discharge cultures from patients hospitalized for more than 2 days (both studies) and a Markov chain Monte Carlo (MCMC) model, applied to all patients hospitalized (R-GNOSIS). RESULTS The absolute risk of acquisition of ESBL-E rectal carriage ranged from 2.4% to 2.9% with an ESBL-E acquisition rate of 2.8 to 3.8 acquisitions per 1,000 patient days. In addition, 28% of acquisitions were attributable to patient-dependent transmission, and the per-admission reproduction number was 0.06. CONCLUSIONS The low ESBL-E acquisition rate in this study demonstrates that it is possible to control the nosocomial transmission of ESBL in a low-endemic, non-ICU setting where Escherichia coli is the most prevalent ESBL-E and standard and contact precautions are applied for known ESBL-E carriers.