Colonization and transmission of high-level gentamicin-resistant enterococci in a long-term care facility.
OBJECTIVE
To assess the prevalence of high-level gentamicin-resistant enterococcus (HGRE) colonization, transmission patterns, and spectrum of illness among residents of a long-term care facility.


METHODS
Monthly surveillance for HGRE colonization of wounds, rectum, and perineum over a 1-year period.


METHODS
A Veterans Affairs long-term care facility attached to an acute-care facility.


METHODS
All 341 patients in the facility during the observation period.


RESULTS
Over the 1-year period, 120 patients (35.2%) were colonized with HGRE at least once, with an overall monthly colonization rate of 20 +/- 1.5%. HGRE were isolated from rectum (12.8%), wounds (11.7%), and perineum (9.3%). Patients with the poorest functional status had the highest rate of colonization (P < 0.0005). HGRE-colonized patients were more likely to be colonized with methicillin-resistant Staphylococcus aureus (51% versus 25%; P < 0.0005). Seventy-four patients (21.7%) were colonized at admission or at the start of the study. Another 46 patients (13.5%) acquired HGRE during the study, including 36 who acquired HGRE while in the long-term care facility and 10 who were positive when transferred back from the acute-care hospital. Based on plasmid profiles, only two patients appeared to have isolates similar to those of current or previous roommates. Carriage of HGRE was transient in most cases. Only 20 patients were colonized for 4 or more months, and those patients usually carried different strains intermittently. Infections were infrequent, occurring in only 4.1% of total patients.


CONCLUSIONS
In our long-term care facility, HGRE were endemic, and new acquisition of HGRE occurred frequently. However, only two patients had evidence of acquisition from a roommate, suggesting that cross-infection from a roommate was not a major route of spread of HGRE.
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor.
C E
CE
Chenoweth
S F
SF
Bradley
M S
MS
Terpenning
L T
LT
Zarins
M A
MA
Ramsey
D R
DR
Schaberg
C A
CA
Kauffman
D015169:Colony Count, Microbial; D003428:Cross Infection / Q000382:microbiology / Q000635:transmission*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004352:Drug Resistance, Microbial; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification*; D005839:Gentamicins / Q000494:pharmacology*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000635:transmission*; D006787:Hospitals, Veterans; D006801:Humans; D008134:Long-Term Care; D008824:Michigan; D011446:Prospective Studies
D004269:DNA, Bacterial; D005839:Gentamicins