Vancomycin resistant Enterococcus in hospital patients

Investigators
A. Padiglione
R. Wolfe
D. Olden
L. Grabsch
S.Pearson
C. Franklin
D. Spelman
B. Mayall
P. Johnson
G. Hogg
M. L. Grayson

Funded by: Dept of Human Services, Victoria and the Centre for Clinical Effectiveness at Monash Medical Centre

The aim of this project was to describe the characteristics of faecal vancomycin-resistant enterococci (VRE) colonisation in high-risk patients of acute-care hospitals with high level infection control procedures in Melbourne, Australia.

This was a prospective, cohort study involving serial rectal swabs performed on patients admitted to high dependency areas (Renal, Intensive care (including general, cardiothoracic and road trauma), Haematology or Transplant units) in acute-care hospitals in metropolitan Melbourne and analysed for VRE colonisation. All hospitals had high level infection control procedures in place prior to commencement of the study. Data was collected on demographic factors and antibiotic exposure.

Faecal colonisation with VRE was detected in 1.56% of admissions (1.91% of patients): 0.45% (0.55% of patients) at admission and 0.83% (1.01% of patients) on a subsequent swab. An additional 0.28% (0.35% of patients) had a delayed first swab so that the time when colonisation occurred could not be accurately determined. VanB E. faecium was the commonest species isolated, accounting for 71% of strains. Renal units appeared to have a higher rate (rate 3.23, 95% CI 1.54 to 6.77) than the overall population (rate 1.4, 95% CI 1.0 to 2.2). Prior use of broad spectrum antibiotics with extended gram negative and anti- anaerobic activity (Imipenem, meropenem, ticarcillin/clavulante) was associated with VRE acquisition(HR 2.4, 95% CI 1.0 to 5.6, p=0.05). There was a lesser association with glycopeptide use (HR 2.1, 95%CI 1.0 to 4.5, p=0.07).

Faecal VRE colonisation continues to occur at a low level in high-risk patients in Melbourne despite infection control efforts. However there was little evidence of clonal spread, and the rate described is considerably lower than that reported from comparable hospitals in other countries. This study also supports a very low rate of VRE faecal colonisation in the general healthy community in Melbourne. Broad-spectrum antibiotics with anti-anaerobic activity may be the most significant risk factor for acquisition of vanB VRE in this low endemicity setting.

Padiglione, A. A., R. Wolfe, et al. (2003). "Risk factors for new detection of vancomycin-resistant enterococci in acute-care hospitals that employ strict infection control procedures." Antimicrobial Agents & Chemotherapy 47(8): 2492-8.