Natural history of colonization with vancomycin-resistant Enterococcus faecium.
OBJECTIVE
To determine the incidence, duration, and genetic diversity of colonization with vancomycin-resistant Enterococcus faecium (VREF).


METHODS
Oncology unit of a 650-bed university hospital.


METHODS
Surveillance perianal swab cultures were performed on admission and weekly. The molecular relatedness of VREF isolates was determined by pulsed-field gel electrophoresis and by the hybridization pattern of the vanA resistance determinant.


RESULTS
During 8 months of surveillance, the VREF colonization rate was 16.6 patients per 1,000 patient-hospital days, which was 10.6 times greater than the VREF infection rate. Eighty-six patients with VREF colonization were identified. Colonization persisted for at least 7 weeks in the majority of patients. Of 36 colonized patients discharged from the hospital and then readmitted, an average of 2 1/2 weeks later, 22 (61%) patients still were colonized with VREF. Of the 14 patients who were VREF-negative at readmission, only three patients remained culture-negative throughout hospitalizations. PFGE demonstrated that colonization with the same VREF isolate may persist for at least 1 year, and patients may be colonized with more than one strain of VREF.


CONCLUSIONS
VREF colonization is at least 10-fold more prevalent than infection among oncology patients. Colonization often persists throughout lengthy hospitalizations and may continue for long periods following hospitalization.
Montecalvo
M A
MA
Department of Medicine, New York Medical College, Valhalla 10595, USA.
de Lencastre
H
H
Carraher
M
M
Gedris
C
C
Chung
M
M
VanHorn
K
K
Wormser
G P
GP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D016172:DNA Fingerprinting; D004352:Drug Resistance, Microbial; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control; D006801:Humans; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D009518:New York / Q000453:epidemiology; D016522:Oncology Service, Hospital; D010356:Patient Isolation; D015995:Prevalence; D014552:Urinary Tract Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology; D014640:Vancomycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D014640:Vancomycin