Genotyping and preemptive isolation to control an outbreak of vancomycin-resistant Enterococcus faecium

Area of Science:

• Infectious Disease Epidemiology
• Hospital Infection Control
• Microbiology

Background:

• Widespread asymptomatic carriage of vancomycin-resistant Enterococcus faecium (VRE) complicates control in European hospitals.
• A significant VRE outbreak occurred at the University Medical Center Utrecht in 2000, necessitating targeted intervention strategies.

Purpose of the Study:

• To evaluate the effectiveness of genotyping-targeted infection control measures in managing a VRE outbreak.
• To assess the impact of different infection control strategies, including surveillance, isolation, and hand hygiene, on VRE spread.

Main Methods:

• Genotyping (pulsed-field gel electrophoresis) distinguished epidemic from nonepidemic VRE strains.
• Infection control measures were retrospectively analyzed across three periods with varying interventions: active surveillance, carrier isolation, cohorting, and preemptive isolation of high-risk patients.
• Compliance with alcohol-based hand rubs was monitored and enforced throughout the study.

Main Results:

• Initially, 93% of VRE-colonized patients carried epidemic strains; detection rates of nonepidemic VRE remained low and stable across all periods.
• The relative risk of detecting epidemic VRE significantly decreased in periods II and III compared to period I, indicating successful control.
• Alcohol-based hand rub usage increased substantially (31%-275%) in outbreak wards, correlating with improved compliance.

Conclusions:

• Genotyping-guided infection control, combined with VRE carrier isolation and enhanced hand hygiene, successfully controlled nosocomial spread of epidemic VRE.
• Preemptive isolation of high-risk patients further contributed to the effective management of VRE outbreaks.
• These targeted strategies demonstrate the feasibility of controlling VRE transmission in healthcare settings.