Recommendations for the successful control of a large outbreak of vancomycin-resistant Enterococcus faecium in a non-endemic hospital setting

Abstract

BACKGROUND: A large outbreak of three epidemic vancomycin-resistant Enterococcus faecium (VRE) clones affected the study hospital for almost two years. AIM: To describe the strategy to successfully control this outbreak and eradicate VRE from the study hospital. METHODS: Infection control interventions started after detection of VRE in three patients. Hospital-wide surveillance was started after ongoing transmission despite isolation precautions, cleaning and contact tracing. Hygiene education and discipline were enhanced. Despite these interventions, additional measures were required to control the outbreak, such as ward disinfection with hydrogen peroxide vapour and the introduction of a VRE quarantine ward. Ultimately, ciprofloxacin prophylaxis for haematological patients on chemotherapy was abandoned. FINDINGS: Over a 22-month period, 242 VRE carriers were identified. Of these, 128 (53%) patients were detected by hospital-wide surveillance alone. Three epidemic clones were detected: ST494-vanA (N = 160), ST78-vanA (N = 23) and ST117-vanB (N = 32). In total, 5614 possible contacts were identified. VRE transmission occurred on 13 out of 23 wards. VRE was cultured from clinical specimens in 22 patients (seven with bacteraemia). Since January 2014, no further transmission of these VRE clones has been observed. CONCLUSION: Infection control measures according to international guidelines were insufficient to expose the outbreak to its full extent and control it. Its full extent only became apparent after sustained hospital-wide screening. Successful control of this hospital-wide VRE outbreak was feasible, but required great effort. Final containment and eradication of the epidemic clones was achieved by environmental decontamination with hydrogen peroxide vapour, strict isolation precautions, a VRE quarantine ward and antimicrobial stewardship.