An outbreak of vanA vancomycin-resistant Enterococcus faecium in a hospital with endemic vanB VRE

Infect Dis Health. 2019 May;24(2):82-91. doi: 10.1016/j.idh.2018.12.002. Epub 2019 Jan 10.

Abstract

Background: In Australia, vanB vancomycin-resistant Enterococcus faecium (VREfm) has been endemic for over 20 years, but vanA VREfm isolates have rarely been reported.

Methods: This outbreak report describes an outbreak of vanA VREfm in the intensive care unit (ICU) and cardiothoracic surgery (CTS) wards of a Melbourne hospital in 2015-2016. After the cluster was initially identified in the ICU ward, an active screening programme was implemented. VRE isolates were typed using in silico multi-locus sequence typing. In addition, to screening, enhanced environmental cleaning, chlorhexidine gluconate body washes, and standardisation of the surgical antibiotic prophylaxis regimen were implemented to control the outbreak.

Results: There were 83 new isolates of vanA VREfm recovered from patients in the ICU (n = 31) and CTS (n = 52) wards. Screening identified 78 (94%) of cases. Three patients required treatment for clinical infection with vanA VREfm during the outbreak. The outbreak was polyclonal with 5 different multilocus sequence types carrying the vanA gene (ST17, ST80, ST203, ST252 and ST1421) detected from a subset of isolates (N = 43). The ST17 isolates all carried both the vanA and vanB gene. The intervention bundle resulted in control of the outbreak after 10 months.

Conclusion: Geographically, vanA VREfm has previously been uncommon in the region and this outbreak represents a change in local epidemiology. Few VRE outbreaks have been reported in CTS patients. The infection control responses controlled the outbreak within 10-months and may help guide future management of outbreaks.

Keywords: Enterococcus faecium; Infection control; Outbreak; VRE; Vancomycin-resistant enterococci; vanA.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology*
  • Australia
  • Bacterial Typing Techniques
  • Disease Management
  • Disease Outbreaks*
  • Endemic Diseases
  • Enterococcus faecium / drug effects*
  • Enterococcus faecium / genetics
  • Female
  • Gram-Positive Bacterial Infections / diagnosis*
  • Gram-Positive Bacterial Infections / microbiology
  • Hospital Units
  • Humans
  • Infection Control
  • Intensive Care Units
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Multilocus Sequence Typing
  • Vancomycin / pharmacology*
  • Vancomycin-Resistant Enterococci / drug effects*
  • Vancomycin-Resistant Enterococci / genetics
  • Young Adult

Substances

  • Anti-Bacterial Agents
  • Vancomycin