What is Vancomycin Resistant Enterococci (VRE)?

Enterococci are bacteria that are normally found in the bowel and the female genital tract. They are normally of very low virulence and therefore they do not cause symptomatic disease in many people. They may cause urinary tract infections and other infections after contamination of the peritoneal cavity. Enteroccocal infections may also be seen in surgical wound infections, liver and intraabdominal abscesses, and foot ulcers in diabetic patients.
Sometimes after exposure to certain antibiotics, drug resistant strains of enterococci may survive and multiply – resulting in an overgrowth of drug resistant bacteria.
VRE itself refers to enterococcal species, namely Enterococcus faecalis and Enteroccocus faecium with the vanA or vanB resistant gene to the antibiotic vancomycin- it is neither more infectious or virulent than other enterococcus species.

Statistics

As stated earlier the Enterococcus species of bacteria are normally found within the gastrointestinal tract – in this form they occasional cause disease. VRE bacteria are more likely in a hospital setting, although they can occur in the community. It is hard to ascertain the true incidence of VRE, as many people are colonised with this bacteria, but it does not cause disease in a large proportion.

Risk Factors

Patients that are at a higher risk of developing colonisation or infection due to VRE include those who:

  • are critically ill (eg in intensive care units);

 

  • are immunosuppressed (eg oncology or transplant patients);
  • have had intra-abdominal or cardiothoracic procedures;
  • have a central venous catheter;
  • have a prolonged hospital stay; or
  • have had recent broad-spectrum antibiotic therapy, or who have received oral
    or intravenous vancomycin.

 
It should be noted that one of the major sources of transmission of VRE in a hospital setting is via the hands of health care workers who may acquire the organism after touching a patient and may transmit by touching another patient without washing their hands.

Progression

VRE colonisation usually precedes infection. This means that patients or healthcare workers usually acquire the bacteria without it causing disease and then transmit it to other people. The bacteria may also be significant enought to cause disease in a person who is colonised, if they are particularly vulnerable. The extent of the disease caused by the bacteria is often dependent on how ill the patient is.

How is it Diagnosed

Blood Tests to determine if there is an infection may include:
 

  • Full blood count – a raised white cell count may be indicative of infection
  • ESR/CRP – these may be raised which is indicative of infection
  • Blood Cultures – may show VRE if relevantSwabs may be taken from relevant infected sites which may isolate the bacteria.

    Treatment

    There is no real consensus on the standards of infection control for multiresistant organisms. The main factors that influence VRE management in Australian hospitals include the endemicity of the organism in the health care establishment as well as the vulnerability of the patients.
    All health facilities should have management plans for VRE. An example plan is outlined here if a patient/s is thought to have a VRE infection:
     

  • Key personell should be notified such as a an infectious disease/clinical microbiologist specialist.
  • The diagnosis should be confirmed by microscopy and culture if appropriate.
  • Contacts of the patient including friends, family members, healthcare workers and other patients should be screened.
  • Transmission risk should be minimised by placing the patient in a single room with single bathroom facilities.
  • Protective apparel such as disposable gloves, gowns and plastic aprons should be used when any visitors or staff see the patient.
  • Designated equipment should be kept for this patient use e.g. stethoscopes, thermometers. Bedding and furniture should also be considered.It should be noted that the emergence of VRE has primarily come about as a result of increased use of broadspectrum antibiotics. In order to help minimise the emergence of new multi-resistant bacteria, the use of antibiotics should be considered on a case by case basis.