Controlling outbreak of vancomycin-resistant Enterococcus faecium among infants caused by an endemic strain in adult inpatients.
BACKGROUND
Vancomycin-resistant Enterococcus faecium (VREfm) is commonly associated with hospital outbreaks and has been found to be associated with increased morbidity, mortality, length of stay, and health care costs.


METHODS
We sought to investigate and control an outbreak of VREfm in the neonatal intensive care unit (NICU) of a public academic hospital with a level III NICU. The index case was an infant in the NICU incidentally identified with urinary colonization with VREfm. Aggressive control measures were initiated promptly. Investigation included active surveillance cultures in infants, parents of colonized infants, and birth mothers of newborn admitted to NICU; molecular strain typing of available isolates of VREfm including adult inpatients; and medical record review.


RESULTS
After identification of index case, 13 additional infants were identified with VREfm colonization. Age at culture was 6 to 87 days; birth weight was 1,070 to 2,834 g. VREfm isolated from majority of infants (12/14 [85.7%]), the birth mother of a pair of colonized twins, and a pulse oximeter device used in adult inpatients belonged to a single strain. Outbreak control measures were successful in the NICU. The outbreak-causing strain was found to be endemic among adult inpatients. Adult patients with the outbreak-causing strain of VREfm were more likely to have received previous therapy with meropenem (Mann-Whitney 2-tailed P value = .038). VRE colonization was identified in 0.3% (1/310) of birth mothers with newborn admitted to NICU.


CONCLUSIONS
An endemic strain of VREfm among adult inpatients was responsible for a subsequently controlled outbreak in the NICU.
Department of Infection Prevention, Parkland Health and Hospital System, 5323 Harry HinesBoulevard, Dallas, TX 75390-9113, USA.
Tobias
T
Pusch
Dale
D
Kemp
Sylvia
S
Trevino
Thomas
T
Button
Pablo
P
Sanchez
Rita
R
Gander
Pranavi
P
Sreeramoju
D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D019353:Endemic Diseases; D016984:Enterococcus faecium / Q000187:drug effects* / Q000302:isolation & purification; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017053:Infection Control / Q000379:methods; D007297:Inpatients; D007363:Intensive Care Units, Neonatal; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D020713:Vancomycin Resistance; D055815:Young Adult