An outbreak of vancomycin-dependent Enterococcus faecium in a bone marrow transplant unit

Area of Science:

• Infectious Diseases
• Microbiology
• Hospital Epidemiology

Background:

• Vancomycin-resistant enterococci (VRE) outbreaks are documented.
• Vancomycin-dependent enterococci (VDE), a VRE mutant, has been found in individual patients.
• The nosocomial spread potential of VDE remained unknown.

Purpose of the Study:

• To report the first documented nosocomial cluster of VDE.
• To investigate the characteristics and management of a VDE outbreak.
• To highlight the risk of VDE transmission in healthcare settings.

Main Methods:

• Retrospective analysis of a VDE outbreak among five bone marrow transplant patients.
• Genotypic characterization of Enterococcus faecium isolates.
• Review of patient treatment, including prophylactic vancomycin exposure.
• Implementation and assessment of infection control strategies.

Main Results:

• A cluster of five bone marrow transplant patients acquired a genotypically identical, multi-antibiotic-resistant Enterococcus faecium strain.
• Vancomycin dependence was confirmed in three of the five isolates.
• All affected patients received prolonged prophylactic vancomycin treatment.
• The outbreak was successfully controlled through enhanced infection control measures.

Conclusions:

• Multi-antibiotic-resistant VDE can spread nosocomially, posing a risk to immunocompromised patients.
• Prolonged vancomycin prophylaxis may be associated with VDE acquisition.
• Vigilance and robust infection control are crucial for managing VDE outbreaks.
• Revision of prophylactic antibiotic policies is essential in preventing VDE transmission.