Patients with chronic renal failure who are undergoing hemodialysis are at increased risk for acquiring VRE. Hemodialysis-dependent patients are at increased risk for VRE for several reasons: they have extensive contact with healthcare system, they are often in close proximity to other VRE patients, they frequently have multiple co-morbid conditions, and they often receive repeated prolonged courses of antibiotics including vancomycin .
To our knowledge, this study is the first to define the prevalence of VRE colonization in a cohort of long-term outpatient dialysis patients in Iran. We found VRE rectal carriage in 6.2% of hemodialysis patients, a result similar to those reported in a number of previous studies that have examined VRE colonization among dialysis patients. VRE prevalence was 9.5% at the center affiliated with the university of Maryland hospital , 9% among 111 dialysis patients near New York City , 6% at the Vanderbilt University Medical Center , and 8.1% at Johns Hopkins University Hospital .
An increased risk of VRE infection and colonization has been associated with non-ambulatory status [6, 7], receipt of antibiotic , hospitalization [6, 8, 9], ICU stays , use of vancomycin [4, 6–8, 10], anemia , and leukocytosis . However, our study found only association between hospitalization and antibiotic consumption with VRE colonization. Interestingly, both patients having received antibiotics within the previous 2 months also have been hospitalized during the past year. The factor 'hospitalization during the past year' might well be a surrogate for antibiotic consumption. It can be speculated that the small number of VRE isolate limited our ability to evaluate risk factors. Furthermore, the yield of rectal swabs when compared to fresh stool samples has been demonstrated not to be high , and the use of broth enrichment might have increased the yield in VRE. Novicki et al. demonstrated in 2004  that addition of a broth enrichment step leads to the detection of significantly more VRE isolates than direct plating alone. Therefore, the used sampling technique might be a second potential limitation of our study with regards to underestimating the true prevalence as well as potential misclassification of controls.
Yet, Reisner et al.  clearly showed that use of an enrichment broth medium is required to recover VRE contaminating environmental surfaces; however, direct inoculation to selective solid medium is adequate to recover VRE in patient perianal specimens. The purpose of our study, however, was not to determine a precise estimation of the prevalence in hemodialysis patients, but to obtain enough information to calculate risk factors for VRE carriage. Furthermore, in an epidemiological sense pertaining to the risk of transmission it remains debatable how relevant a VRE carrier is, if the isolate is only detectable by means of enrichment cultures.
Because there is no commonly agreed regimen to eradicate VRE colonization, efforts to preventing VRE's spread are paramount . Current experience emphasizes continued enforcement of infection-control measures and prudent use of antibiotics. These interventions may have a beneficial impact on the rapidly rising rates of VRE among chronic hemodialysis patients. However, improving compliance with infection control measures and prudent use of antibiotics will be challenging, since generally, compliance is low.