EPIDEMIOLOGY OF COLONIZATION OF PATIENTS AND ENVIRONMENT WITH VANCOMYCIN-RESISTANT ENTEROCOCCI

Background Vancomycin-resistant enterococci (VRE) have emerged as noso comial pathogens during the past 5 years, but little is known about th e epidemiology of VRE. We investigated colonisation of patients and en vironmental contamination with VRE in an endemic setting to assess the importance of different sources of colonisation. Methods Between Apri l 12, and May 29, 1995, cultures from body sites (rectum, groin, arm, oropharynx, trachea, and stomach) and from environmental surfaces (bed rails, drawsheet, blood-pressure cuff, urine containers, and enteral f eed) were obtained dairy from ail newly admitted Ventilated patients i n our medical intensive-care unit (MICU). Rectal cultures were obtaine d from all nonventilated patients in the MICU. Strain types of VRE wer e determined by pulsed-field gel electrophoresis. Findings There were 97 admissions of 92 patients, of whom 38 required mechanical ventilati on. Colonisation with VRE on admission was more common in Ventilated t han in non-ventilated patients (nine [24%] vs three [6%], p<0.05). Of the nine ventilated patients colonised with VRE on admission, one acqu ired a new strain of VRE in the MICU. Of the 29 ventilated patients wh o were not colonised with VRE on admission, 12 (41%) acquired VRE in t he MICU. The median time to acquisition of VRE was 5 days (interquarti le range 3-8). Of the 13 Ventilated patients who acquired VRE, 11 (85% ) were colonised with VRE by cross-colonisation, VRE were isolated fro m 157 (12%) of 1294 environmental cultures. The rooms of 13 patients w ere contaminated with VRE, but only three (23%) of these patients subs equently acquired colonisation with VRE. Pulsed-field gel electrophore sis of 262 isolates showed 20 unique strain types of VRE. Interpretati on Frequent colonisation with VRE on MICU admission and subsequent cro ss-colonisation are important factors in the endemic spread of VRE, Pe rsistent VRE colonisation in the gastrointestinal tract and on the ski n, the presence of multiple-strain types of VRE, and environmental con tamination may all contribute to the spread of VRE.