Outbreak of vanB vancomycin-resistant Enterococcus faecium colonization in a neonatal service

Abstract

OBJECTIVE: To describe successful termination of an outbreak of vancomycin-resistant Enterococcus faecium (VREfm) colonization within a neonatal service. SETTING: Multisite neonatal intensive care unit and special care nurseries within a single health care service. PARTICIPANTS: Forty-four cases of VREfm-colonized neonatal inpatients-including 2 clinical isolates (eye swab and catheter-urine specimen) and 42 screening isolates. INTERVENTIONS: Active surveillance cultures, patient isolation, contact precautions, enhanced environment cleaning, and staff and parent education. Whole genome sequencing and multilocus sequence typing were used to characterize the outbreak and refine infection control procedures. RESULTS: Peak prevalence of VREfm colonization across all sites was 31% upon discovery of the outbreak. Subsequent to the intervention, transmission was halted within 8 weeks and no further isolates of the outbreak strain have been detected as of 12 months following outbreak cessation. Environmental swabs revealed VREfm colonization of baby-weighing scales, a baby bath, and a pharmacy refrigerator within the neonatal intensive care unit. All isolates were of a single multilocus sequence type (sequence type 796) and highly clonal at the core genome level. CONCLUSIONS: Bundled infection control interventions were effective in rapidly terminating a clonal outbreak of sequence type 796 VREfm colonization within a neonatal inpatient service. Strain-typing and active surveillance cultures were critical in guiding the management of this outbreak. The closed environment of a neonatal unit likely facilitated eradication of the patient and environment reservoirs of VREfm colonization.