Risk factors for colonization with vancomycin-resistant enterococci in a Melbourne hospital.
OBJECTIVE
To determine risk factors for colonization with vancomycin-resistant enterococci (VRE) in a hospital outbreak.


METHODS
Outbreak investigation and case-control study.


METHODS
A referral teaching hospital in Melbourne, Australia.


METHODS
Cases were inpatients colonized (with or without clinical disease) with VRE between July 26 and November 28, 1998; controls were hospitalized patients without VRE.


METHODS
Five cases of VRE were identified between July 26 and November 8, 1998, by growth of VRE from various sites. Active case finding by cultures of rectal swabs from patients surveyed in wards was commenced on July 26, after the first isolate of VRE.


RESULTS
There were 19 cases and 66 controls. All the VRE identified were vanB, and all were Enterococcus faecium. One molecular type predominated (18/19 cases). In a logistic-regression model, being on the same ward as a VRE case was the highest risk factor (odds ratio [OR], 82; 95% confidence interval [CI95], 5.7-1,176; P=.001). Having more than five antibiotics (OR, 11.9; CI95 1.1-129.6; P<.05), use of metronidazole (OR, 10.9; CI95, 1.7-69.8; P=.01), and being a medical patient (OR, 8.1; CI95, 1.4-47.6; P<.05) also were significant. Intensive care unit admission was associated with decreased risk (OR, 0.1; CI95, 0.01-0.8; P<.05).


CONCLUSIONS
Our findings are consistent with an acute hospital outbreak. Monitoring and control of antibiotic use, particularly metronidazole, may reduce VRE in our hospital. Ongoing surveillance and staff education also are necessary.
MacIntyre
C R
CR
National Centre for Immunisation Research, New Children's Hospital, Westmead, New South Wales, Australia.
Empson
M
M
Boardman
C
C
Sindhusake
D
D
Lokan
J
J
Brown
G V
GV
D016022:Case-Control Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D016984:Enterococcus faecium / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006784:Hospitals, Teaching; D006801:Humans; D008875:Middle Aged; D012307:Risk Factors; D020713:Vancomycin Resistance; D014739:Victoria / Q000453:epidemiology