Reduction of nosocomial bloodstream infections and nosocomial vancomycin-resistant Enterococcus faecium on an intensive care unit after introduction of antiseptic octenidine-based bathing

Summary

Background

Vancomycin-resistant Enterococcus faecium (VRE) is emerging in German intensive care units (ICUs). On a 32-bed surgical ICU at a university hospital, increasing numbers of nosocomial cases occurred despite enforcement of hand hygiene and environmental disinfection.

Aim

To introduce universal octenidine-based bathing in order to reduce the burden of VRE.

Methods

Between January 2012 and March 2014, patients were screened for VRE on admission and twice weekly. Active surveillance was undertaken for VRE infections and colonizations, and for bloodstream infections (BSI) with any pathogen. Intervention in this before–after study comprised of standardized octenidine-based bathing. Distinct subgroups of VRE colonizations or infections were defined and used for statistical analysis of frequency, prevalence and incidence density.

Findings

In the pre-intervention period (January 2012 to April 2013), the admission prevalence of VRE was 4/100 patients and the mean incidence density of nosocomial cases was 7.55/1000 patient-days (PD). Pulsed-field gel electrophoresis analysis revealed prevalence of three vanA and two vanB clusters. In the post-intervention period (August 2013 to March 2014), the admission prevalence of VRE was 2.41/100 patients and the mean incidence density of nosocomial cases was 2.61/1000 PD [P = 0.001 (pre- vs post-intervention)]. Thirteen nosocomial VRE infections were identified in the pre-intervention period, compared with one nosocomial VRE infection in the post-intervention period. Incidence densities of BSI pre- and post-intervention were 2.98 and 2.06/1000 PD (P = 0.15), respectively.

Conclusion

The epidemiology of emerging VRE appeared as a complex mix of admitted cases and transmissions in small clusters, challenging infection control measures. The implementation of universal octenidine-based bathing combined with a standardized washing regime led to a significant reduction in nosocomial VRE.

Introduction

In recent years, vancomycin resistance of enterococci, mainly Enterococcus faecium, has increased in clinically relevant samples from patients in Europe [1]. Additionally, vancomycin-resistant E. faecium (VRE) detection in clinical specimens has shown a spatial distribution. In 2012, the percentage of vancomycin resistance of enterococci was between 1% and 5% in Spain, between 5% and 10% in Italy and Poland, between 10% and 25% in Germany and Great Britain, and between 25% and 50% in Ireland [1]. In Germany, the Krankenhaus-Infektions-Surveillance-System detected a dramatic increase in nosocomial VRE infections with a large variation in VRE proportions of all enterococcal infections from west (North Rhine-Westphalia) to east (Saxony) [2], [3]. Cologne is sited within this belt, and the VRE proportion in blood cultures in a university hospital was 0% (0/20) and 35% (7/20) VRE/E. faecium in 2010 and 2011, respectively.

In 2011, three VRE infections emerged in a surgical intensive care unit (ICU) at the study hospital within two weeks. Therefore, infection control activities were intensified by introducing an active surveillance system for VRE, enforcing hand hygiene and additional environmental cleaning and disinfection; this system was fully implemented in December 2011. The National Reference Centre (NRC) for Staphylococci and Enterococci in Germany performed an analysis of all VRE isolates for the presence of pathogenicity markers hyl and esp and resistance genes vanA or vanB. This analysis showed primarily heterogenic epidemiology in the ICU. In 2012, VRE cases continued to increase despite all infection control measures. Therefore, in 2013, the decision was made to introduce a whole-body washing procedure for all patients.

Initial studies showed that antiseptic washing with chlorhexidine led to a reduction in VRE, and this appeared to be a promising option in the study setting [4], [5], [6]. At the time, chlorhexidine was not commercially available for antiseptic body washing in German hospitals. The alternative in Germany was octenidine, which was available as a body wash soap (Octenisan containing 0.3% octenidine), and had been in use for many years for decolonization of meticillin-resistant Staphylococcus aureus (MRSA)-positive patients. Octenidine has shown excellent activity against most relevant bacteria [6], [7], [8]. The primary aim of this intervention study was to control VRE colonizations and infections. A reduction in bloodstream infections (BSI) was included as a secondary outcome to enable comparability with other recently published studies using chlorhexidine for daily body washing [4], [9], [10].