Vancomycin-Resistant Enterococcus (VRE) Program of Research

In response to stakeholder requests for more evidence on the impacts of VRE IPAC strategies, PHO has developed a diverse VRE program of research that asks four key questions: 

Are outcomes different for VRE vs VSE (Vancomycin-Susceptible Enterococcus) bacteremia?

To answer this question, PHO conducted a systematic review. Titled "VRE and VSE Bacteremia Outcomes in the Era of Effective VRE Therapy: A Systematic Review and Meta-Analysis”, the review was published in the Journal of Infection Control and Hospital Epidemiology in October 2015. The key finding was that VRE bacteremia mortality burden is greater than that of VSE bacteremia, even following the availability of effective anti-VRE treatments (OR 1.80 [1.38, 2.35]: I2=0%).

Are VRE screening and isolation practices associated with rates of VRE+ blood cultures? 

To answer this question, PHO conducted a study to examine the VRE-positive blood culture trends in Ontario from January 2009 to June 2015 using patient safety public reporting data, in combination with the results from an annual screening and isolation practices scan conducted in 2013, 2014 and 2015. The study entitled "Rates of blood cultures positive for vancomycin-resistant Enterococcus in Ontario: a quasi-experimental study" was published in CMAJ Open in April 2017. Key findings from this study include: 

• Rates of VRE-positive blood cultures have doubled in Ontario between January 2009 and July 2015
• Discontinuation of VRE screening was associated with an increased rate of rise of VRE-positive blood cultures
• While VRE positive blood cultures have increased in both screening and non-screening hospitals over time, discontinuation of VRE screening was associated with an increased rate of rise in VRE positive blood cultures  

What are the risk factors for VRE+ blood cultures?

To answer this question, PHO in partnership with ICES in 2018 published a population-based case control study entitled, “Patient- and hospital-level predictors of vancomycin-resistant Enterococcus (VRE) bacteremia in Ontario, Canada” in the American Journal of Infection Control  that looked at a cohort of 217 VRE positive patients in Ontario from January 2009 to December 2013. Key results from this study include: 

• Forty percent of patients with VRE bacteremia died within 30 days.
• Patients with a bone marrow transplant, solid organ transplant, cancer, or who are admitted to      the intensive care unit are at highest risk of VRE bacteremia.
• Larger hospital size and teaching hospitals were independent predictors of VRE bacteremia

What are the economic impacts associated with VRE IPAC strategies?

To answer this question, PHO is conducting a systematic review on the economic impacts of infection control interventions for VRE, such as screening and isolation practices. Results from this systematic review are expected fall 2019. 

Further, in partnership with ICES PHO is conducting a population-based case cohort study of hospitalized patients with confirmed VRE bacteremia in Ontario, Canada, between January 2009 and December 2013 to evaluate the costs attributable to VRE bacteremia from the healthcare payer perspective.  Results from this study are expected winter 2019. 

PIDAC Recommendation

The Provincial Infectious Diseases Advisory Committee on Infection Prevention and Control (PIDAC-IPC) has re-assessed its evidence-based guidance for VRE control and in 2019 recommends that all acute care and chronic care hospitals as well as long-term care homes continue to perform risk-factor-based screening on admission and Contact Precautions for VRE. The findings and priorities for future research, together with the revised recommendations, are summarized in the document: Evidence Review and Revised Recommendations for the Control of Vancomycin-Resistant Enterococci in All Ontario Health Care Facilities.

For more information on the VRE program of research or for any questions related to VRE IPAC strategies, please contact ipac@oahpp.ca.