Interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in intensive care units: an interrupted time series study and cluster randomised trial

Abstract

SummaryBackgroundIntensive care units (ICUs) are high-risk areas for transmission of antimicrobial-resistant bacteria, but no controlled study has tested the effect of rapid screening and isolation of carriers on transmission in settings with best-standard precautions. We assessed interventions to reduce colonisation and transmission of antimicrobial-resistant bacteria in European ICUs.MethodsWe did this study in three phases at 13 ICUs. After a 6 month baseline period (phase 1), we did an interrupted time series study of universal chlorhexidine body-washing combined with hand hygiene improvement for 6 months (phase 2), followed by a 12–15 month cluster randomised trial (phase 3). ICUs were randomly assigned by computer generated randomisation schedule to either conventional screening (chromogenic screening for meticillin-resistant Staphylococcus aureus [MRSA] and vancomycin-resistant enterococci [VRE]) or rapid screening (PCR testing for MRSA and VRE and chromogenic screening for highly resistant Enterobacteriaceae [HRE]); with contact precautions for identified carriers. The primary outcome was acquisition of resistant bacteria per 100 patient-days at risk, for which we calculated step changes and changes in trends after the introduction of each intervention. We assessed acquisition by microbiological surveillance and analysed it with a multilevel Poisson segmented regression model. We compared screening groups with a likelihood ratio test that combined step changes and changes to trend. This study is registered with ClinicalTrials.gov, number NCT00976638.FindingsSeven ICUs were assigned to rapid screening and six to conventional screening. Mean hand hygiene compliance improved from 52% in phase 1 to 69% in phase 2, and 77% in phase 3. Median proportions of patients receiving chlorhexidine body-washing increased from 0% to 100% at the start of phase 2. For trends in acquisition of antimicrobial-resistant bacteria, weekly incidence rate ratio (IRR) was 0·976 (0·954–0·999) for phase 2 and 1·015 (0·998–1·032) for phase 3. For step changes, weekly IRR was 0·955 (0·676–1·348) for phase 2 and 0·634 (0·349–1·153) for phase 3. The decrease in trend in phase 2 was largely caused by changes in acquisition of MRSA (weekly IRR 0·925, 95% CI 0·890–0·962). Acquisition was lower in the conventional screening group than in the rapid screening group, but did not differ significantly (p=0·06).InterpretationImproved hand hygiene plus unit-wide chlorhexidine body-washing reduced acquisition of antimicrobial-resistant bacteria, particularly MRSA. In the context of a sustained high level of compliance to hand hygiene and chlorhexidine bathings, screening and isolation of carriers do not reduce acquisition rates of multidrug-resistant bacteria, whether or not screening is done with rapid testing or conventional testing.FundingEuropean Commission.

Empfehlungen zur Prävention und Kontrolle von Methicillin-resistenten Staphylococcus aureus-Stämmen (MRSA) in medizinischen und pflegerischen Einrichtungen

“…Zusätzlich sind in jüngster Zeit verschiedene Studien erschienen, die neben MRSA-spezifischen Maßnahmen universelle, erregerunabhängige Dekolonisationsmaßnahmen untersucht haben [365][366][367][368]. Dieser "horizontale" Ansatz der Infektionsprävention ist nicht patienten- [370][371][372].…”

Rates of blood cultures positive for vancomycin-resistant Enterococcus in Ontario: a quasi-experimental study

“…19,20 Active screening programs increase the identification of patients colonized with VRE and reduce the time before contact precautions are implemented. 21 However, the efficacy of contact precautions to prevent the spread of antimicrobial-resistant organisms including VRE has been questioned in 2 randomized controlled trials, 22,23 and studies investigating the impact of discontinuation of VRE screening and isolation practices have given conflicting results. [24][25][26][27] Infection control practices for VRE in Canadian institutions are increasingly heterogeneous, and there is no clear consensus on the best approach.…”

Insight Into the Complex Epidemiology of Multidrug-Resistant Enterobacteriaceae

“…In the study by Derde et al, the same technique was used for all Enterobacteriaceae species [6]. In consequence, a suboptimal sensitivity would equally impact both bacterial groups, with a moderate influence on the reproductive number.…”

“…Among ESCresistant Enterobacteriaceae cultured from colonized patients, 88.7% were phenotypically determined as ESBL-producers [6]. The epidemiology and transmissibility of organisms with plasmidic resistance support may substantially differ from chromosomic resistance mechanisms (e.g.…”