The first outbreak of VRE in Canada was identified following the isolation of VRE from 2 dialysis patients. Active surveillance with perirectal swabs of all contacts and over 400 dialysis patients identified 41 colonized and 1 infected patient between 5/8/95 and 31/10/95; 40 (95%) were receiving dialysis and 2 were contacts. The mean age was 63 yrs (range 29-90); 30 (71%) were either bedridden or had limited activity; 20 (48%) had diarrhea; 7(17%) had fecal incontinence and 9/20 (45%) with diarrhea had stools positive for Clostridium difficile toxin. Forty (95%) had received at least 1 antibiotic, 29 (70%) had multiple (>2) antibiotics and 17 (40%) had received vancomycin (van). Surveillance cultures from hospital staff and the environment revealed VRE in 0/42 staff and 10/140 environmental sites (4 call bells, 2 bed rails, 2 toilet seats, and 2 bathroom floors). Forty-one (98%) of the clinical and all environmental isolates were a sorbitol positive, ampicillin resistant E. faecium with van MICs ranging from 4-128 µg/ml (32% with an MIC < 8 µg/ml). Polymerase chain reaction genotyping was positive for the Van B gene and pulsed-field gel electrophoresis revealed a clonal origin (<2 bands difference) for 51/52 isolates. In 32% of specimens, growth was apparent only after 48 hrs on the m-enterococcal screen plates. Despite the implementation of cohorting, contact isolation and enhanced environmental disinfection 3 patients negative on initial screening were found to be positive on repeat screening. The presence of a strain of VRE exhibiting "low level" resistance, a patient population with a relatively high burden of illness, and the high frequency of antimicrobial usage may have facilitated the rapid spread of VRE in a dialysis population. Further studies on the impact of "low level" resistance are required.

• A VRE outbreak had not previously been described in Canada

• TTH is a 1200 bed tertiary care center and a large dialysis program

• Isolation of VRE from 2 urine isolates in dialysis patients prompted investigation
  

• 0/42 hospital staff swabs positive

• Environmental Cultures (10 of 140 +ve)
  
  • call bells (4+)
    
  • toilet seats (2+)
    
  • bedrails (2+)
  • bathroom floor (2+)
    

• 41/42 clinical isolates and all environmental isolates were a sorbitol +, ampicillin resistant E. faecium
• Vancomycin MICs ranged from 4-128 mg/ml
• 31% of isolates had MICs < 8 mg/ml and in 32% growth only apparent after 48 hrs on m-enterococcal screen plates
  
• PFGE revealed a clonal origin (<2 band difference) for 51/52 isolates
• PCR genotyping was positive for the VAN B gene for all isolates
  

CONTROL MEASURES

• Colonized patients cohorted and cared for on a separate wing; BSP; extensive environmental cleaning were effective
  
• 3 patients negative on initial screening were +ve on repeat screening
  

CONCLUSIONS

• VRE patients were ill, on multiple antibiotics; often had poor hygiene with diarrhea +/- fecal incontinence

• Environmental surfaces may be easily contaminated with VRE

• Our strain posed an unusual problem with identification due to the presence of 'low-level' resistance

• A dialysis population may represent a group at increased risk for colonization and spread of VRE
  

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