Vancomycin-resistant Enterococcus.

Area of Science:

• Infectious Diseases
• Microbiology
• Epidemiology

Background:

• Reported vancomycin-resistant Enterococcus faecium (VRE) prevalence in Switzerland was low (<5%) between 2008-2010.
• University Hospital Zurich detected 17 VRE cases between December 2009 and February 2010, primarily in the cardiac surgery department.
• The outbreak resulted in four VRE infections and four patient deaths.

Purpose of the Study:

• To investigate and contain a VRE outbreak at the University Hospital Zurich.
• To identify the sources and transmission routes of VRE within the hospital.
• To evaluate the effectiveness of implemented infection control measures.

Main Methods:

• Conducted prevalence surveys with weekly rectal screening and environmental screening.
• Utilized selective enrichment culturing for VRE detection.
• Employed pulsed field gel electrophoresis (PFGE) for clonal typing and polymerase chain reaction (PCR) for resistance and virulence factor analysis.
• Implemented contact isolation, enhanced surface disinfection, and hand hygiene education for healthcare workers.

Main Results:

• PFGE identified two main VRE pulsotypes (seven patients each) and five minor pulsotypes.
• PCR analysis revealed vanB resistance genotypes in most cases, with one vanA genotype.
• The outbreak was linked to environmental contamination and poor hand hygiene compliance.
• Enhanced infection control measures led to the outbreak's termination within eight weeks.

Conclusions:

• The VRE outbreak highlights the importance of stringent infection control measures, including screening, disinfection, and hand hygiene.
• The presence of multiple VRE clones suggests a potentially higher baseline prevalence in Switzerland than previously reported.
• Continuous surveillance and rapid response are crucial for managing healthcare-associated infections.