Prevalence and determinants of fecal colonization with vancomycin-resistant enterococcus in hospitalized patients in the Netherlands

OBJECTIVE: To determine the prevalence and determinants of fecal carriage o f vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hema tology-oncology, and hemodialysis patients in The Netherlands. DESIGN: Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and 1998 POPULATION: All patients hospitalized on the testing days in ICUs and hemat ology-oncology wards in nine hospitals in The Netherlands were included. METHODS: Rectal swabs obtained from 1,112 patients were screened for entero cocci in a selective broth and subcultured on selective media with and with out 6 mg/L vancomycin. Resistance genotypes were determined by polymerase c hain reaction. Further characterization of VRE strains was done by pulsed-f ield gel electrophoresis (PFGE). We studied possible determinants of VRE co lonization with a logistic regression analysis model. Determinants analyzed included gender, age, and log-transformed length of prior hospital stay. RESULTS: The results showed that 614 (55%) of 1,112 patients were colonized with vancomycin-sensitive enterococci, and 15 (1.4%) of 1,112 carried VRE. No increase in VRE colonization was observed from 1995 to 1998. Eleven str ains were identified as Enterococcus faecium and four as Enterococcus faeca lis. All E faecium and one E faecalis carried the vanA gene; the other E fa ecalis strains harbored the vanB gene. PFGE revealed that three vanB VRE is olated from patients hospitalized in one single ICU were related, suggestin g nosocomial transmission. Though higher age seemed associated with VRE col onization, exclusion of patients with the nosocomial strain from the regres sion analysis decreased this relation to nonsignificant. Duration of hospit al stay was not associated with VRE colonization. CONCLUSION: VRE colonization in Dutch hospitals is an infrequent phenomenon . Although nosocomial spread occurs, most observed cases were unrelated, wh ich suggests the possibility of VRE acquisition from outside the hospital. Prolonged hospital stay, age, and gender proved unrelated to VRE colonizati on (Infect Control Hosp Epidemiol 2000;21:520-524).