Vancomycin-Resistant Enterococcus Faecium in a Neonatal Intensive Care Unit — Utah, 2013

BACKGROUND: Colonization and subsequent infection with vancomycin-resistant Enterococcus faecium is associated with increased morbidity, mortality, and health care costs. In January 2013, Hospital A was notified that a patient transferred from their neonatal intensive care unit had tested positive for vancomycin-resistant Enterococcus faecium colonization. Hospital A implemented multiple rounds of active surveillance of neonatal intensive care unit patients, the first of which identified 4 additional vancomycin-resistant Enterococcus faecium-colonized infants. Control measures, including active surveillance, contact precautions, and enhanced environmental cleaning, were progressively implemented. We investigated to characterize the outbreak and assess control measure effectiveness.

METHODS: A case was defined as ≥1 clinical or surveillance culture-positive result for vancomycin-resistant Enterococcus faecium in a neonatal intensive care unit patient during January–November 2013. Environmental samples were tested in February, March, April, and July. Case-patients’ medical records were reviewed, and vancomycin-resistant Enterococcus faecium isolates were evaluated by pulsed-field gel electrophoresis.

RESULTS: We identified 47 cases (45 colonizations, 2 infections). Median patient age was 48 (range: 13–400) days. Peak incidence occurred in March (11 cases). No cases were identified after August. Median time from neonatal intensive care unit admission to positive vancomycin-resistant Enterococcus faecium culture was 30 (range 0–263) days. Only 1 of 15 case-patients cultured at admission to the unit was positive for vancomycin-resistant Enterococcus faecium. Of 29 patient isolates typed by pulsed-field gel electrophoresis, 7 belonged to pattern one and 21 to pattern two. During February–April, 21 of 125 (17%) environmental cultures were vancomycin-resistant Enterococcus faecium–positive, compared with 2 of 44 (5%) in July. All environmental isolates typed by pulsed-field gel electrophoresis matched patient isolate patterns one (3 isolates) or two (5 isolates).

CONCLUSIONS: An outbreak with 2 vancomycin-resistant Enterococcus faecium clones occurred in a neonatal intensive care unit. Implementation of control measures was able to reduce environmental contamination, halt transmission, and eventually, eliminate vancomycin-resistant Enterococcus faecium from the unit. A case-control study is under way to assess potential risk factors for guiding prevention and surveillance strategies.