Risk Factors and Outcomes of Vancomycin-Resistant Enterococcus Colonization in Patients on Peritoneal Dialysis: A Single-Center Study in Hong Kong

BACKGROUND

Vancomycin-resistant Enterococcus (VRE) colonization is common among patients with chronic kidney disease. However, data concerning VRE colonization among patients receiving peritoneal dialysis (PD) is lacking. The aim of this study is to evaluate the risk factors and various clinical outcomes for VRE colonization among PD patients.

METHODS

This is a retrospective cohort study of 166 PD patients who were hospitalized between 1 August 2013 and 31 July 2014. They were screened for VRE colonization status during a major VRE outbreak in Hong Kong in 2013 and were then categorized into 2 groups: VRE-positive and VRE-negative. The primary outcome was all-cause mortality while the secondary outcomes included VRE infection, PD-related peritonitis, and length of hospitalization.

RESULTS

Twenty-eight patients (16.9%) belonged to the VRE-positive group. Multivariate analysis showed that previous contact with VRE-positive patients (odds ratio [OR]: 417.86; 95% confidence interval [CI]: 17.21 - 10,147.26, p < 0.01), vancomycin use in previous 3 months (OR: 130.32; 95% CI: 5.35 - 3,176.30, p < 0.01), and old age (OR: 1.13; 95% CI: 1.02 - 1.24, p = 0.02) were the independent risk factors for VRE colonization. Patients in the VRE-positive group had significantly longer length of hospitalization, but there was no significant difference in all-cause mortality and peritonitis-free survival.

CONCLUSION

Vancomycin-resistant Enterococcus colonization is important among hospitalized PD patients. Cautious use of antibiotics and infection control measures are necessary to prevent VRE spreading, especially in high-risk patients.

Vancomycin-resistant enterococci colonization among dialysis patients: a meta-analysis of prevalence, risk factors, and significance

BACKGROUND

Vancomycin-resistant enterococci (VRE) have become important nosocomial pathogens causing outbreaks worldwide. Patients undergoing dialysis represent a vulnerable population due to their comorbid conditions, frequent use of antibacterial agents, and frequent contact with health care settings.

STUDY DESIGN

Systematic review and meta-analysis of cross-sectional studies of screening for VRE colonization.

SETTING & POPULATION

Patients receiving long-term dialysis treatment.

SELECTION CRITERIA FOR STUDIES

We performed a systematic literature search of PubMed and EMBASE databases to identify studies performing screening for VRE colonization among dialysis patients.

PREDICTOR

Region, recent use of vancomycin or other antibiotics, previous hospitalization.

OUTCOMES

(1) VRE colonization and (2) rate of VRE infection among colonized and noncolonized individuals. Relative effects were expressed as ORs and 95% CIs.

RESULTS

We identified 23 studies that fulfilled the inclusion criteria and provided data for 4,842 dialysis patients from 100 dialysis centers. The pooled prevalence of VRE colonization was 6.2% (95% CI, 2.8%-10.8%), with significant variability between centers. The corresponding number for North American centers was 5.2% (95% CI, 2.8%-8.2%). Recent use of any antibiotic (OR, 3.62; 95% CI, 1.22-10.75), particularly vancomycin (OR, 5.15; 95% CI, 1.56-17.02), but also use of antibiotics other than vancomycin (OR, 2.92; 95% CI, 0.99-8.55) and recent hospitalization (OR, 4.55; 95% CI, 1.93-10.74) significantly increased the possibility of a VRE-positive surveillance culture. Colonized patients had a significantly higher risk of VRE infection (OR, 21.62; 95% CI, 5.33-87.69) than their noncolonized counterparts.

LIMITATIONS

In 19 of 23 studies, a low percentage of dialysis patients (<80%) consented to participate in the screening procedure. 4 of 8 studies in which patients were followed up for more than 1 month reported VRE infections and only 5 of 23 studies provided extractable data for antibiotic consumption prior to screening.

CONCLUSIONS

VRE colonization is prevalent in dialysis centers. Previous antibiotic use, in particular vancomycin, and recent hospitalization are important predicting factors of colonization, whereas the risk of VRE infection is significantly higher for colonized patients.

Outpatient vancomycin use and vancomycin-resistant enterococcal colonization in maintenance dialysis patients

BACKGROUND

Although outpatient vancomycin is widely used as empiric therapy for dialysis-associated infections, its relationship with vancomycin-resistant enterococcal (VRE) colonization is not established.

METHODS

During a two-year prospective cohort study, rectal swabs obtained from patients at the start and finish of the study period and during interim hospitalizations were cultured for VRE.

RESULTS

Ten of 124 patients initially grew VRE. Twenty-four of the remaining patients had no follow-up cultures because of patient death (62%), transfer to another dialysis facility (17%), patient's refusal (7%), and transplantation (4%), and were thus excluded. The remaining patients (N = 90) had a median age of 54.3 years and were 92% African American and 50% male. Fifty-eight percent were treated by hemodialysis. They received 403 g of intravenous vancomycin over 157.2 patient-years of follow-up, 73% as outpatients. Sixteen of 90 patients (17.8%) became colonized with VRE, an incidence rate of one case per 9.8 patient-years of follow-up. None of the 29 patients who did not receive vancomycin developed VRE compared with 26% of those treated with vancomycin (P = 0.001). The odds ratio (95% CI) for the association of outpatient vancomycin (g per year) with VRE colonization was 1.23 (1.05, 1.44, P = 0.008). The association remained significant following adjustment in separate logistic regression analyses for relevant demographic, clinical, antimicrobial (inpatient vancomycin, oral or intravenous cephalosprins, aminoglycosides, quinalones, or antianaerobics), and hospitalization exposures. The unadjusted relative risk of death in patients growing VRE was significantly higher than in those not colonized with VRE (P = 0.005).

CONCLUSIONS

VRE colonization is a relatively common and under recognized problem among chronic dialysis patients. It is strongly and independently associated with the outpatient use of vancomycin, which should be avoided whenever possible.

Rectal colonization with vancomycin-resistant enterococci among high-risk patients in an Israeli hospital

The prevalence of rectal carriage of vancomycin-resistant enterococci (VRE) in two high-risk populations--61 patients admitted to ICU and 92 patients on renal dialysis--was studied longitudinally over a period of six months in a 650-bed general hospital. ICU patients were swabbed weekly and dialysis patients monthly. Enterococcal isolates were fully identified using the ATB identification system, and MICs were determined according to the NCCLS recommendations. Enterococci were isolated in 52 (83.6%) ICU patients and 86 (93.4%) dialysis patients. VRE were recovered at least once in 14 (27%) ICU patients and four (4.8%) dialysis patients. All VRE isolates (MIC of vancomycin > or = 256 micrograms/mL) were resistant to teicoplanin (MIC > or = 32 micrograms/mL; vanA phenotype), 87.5% were ampicillin-resistant, and 92% showed high-level resistance to gentamicin; 88% were E. faecium. The main risk factors for acquisition of VRE included duration of hospitalization in the six months preceding entry into the study and during the survey (P = 0.009 and 0.007 respectively, for ICU patients), and duration of antibiotic administration (P = 0.005, for ICU patients). The impact of vancomycin was most prominent (P = 0.005 for receipt and 0.06 for duration of administration, in ICU patients). Six of the 18 VRE carriers developed bacteraemia, six isolates being vancomycin-susceptible and one vancomycin-resistant (one patient had both). In this study, the first in Israel, a low rectal carriage rate occurred in renal dialysis patients and antibiotic use was the most important risk factor for VRE colonization.