Carbapenem-resistant Klebsiella pneumoniae producing New Delhi metallo-ß-lactamase at an acute care hospital, Colorado, 2012.

OBJECTIVE: To investigate an outbreak of New Delhi metallo-ß-lactamase (NDM)-producing carbapenem-resistant Enterobacteriaceae (CRE) and determine interventions to interrupt transmission. DESIGN, SETTING, AND PATIENTS: Epidemiologic investigation of an outbreak of NDM-producing CRE among patients at a Colorado acute care hospital. METHODS: Case patients had NDM-producing CRE isolated from clinical or rectal surveillance cultures (SCs) collected during the period January 1, 2012, through October 20, 2012. Case patients were identified through microbiology records and 6 rounds of SCs in hospital units where they had resided. CRE isolates were tested by real-time polymerase chain reaction for blaNDM. Medical records were reviewed for epidemiologic links; relatedness of isolates was evaluated by pulsed-field gel electrophoresis (PFGE) and whole genome sequencing (WGS). Infection control (IC) was assessed through staff interviews and direct observations. RESULTS: Two patients were initially identified with NDM-producing CRE during July-August 2012. A third case patient, admitted in May, was identified through microbiology records review. SC identified 5 additional case patients. Patients had resided in 11 different units before identification. All isolates were highly related by PFGE. WGS suggested 3 clusters of CRE. Combining WGS with epidemiology identified 4 units as likely transmission sites. NDM-producing CRE positivity in certain patients was not explained by direct epidemiologic overlap, which suggests that undetected colonized patients were involved in transmission. CONCLUSIONS: A 4-month outbreak of NDM-producing CRE occurred at a single hospital, highlighting the risk for spread of these organisms. Combined WGS and epidemiologic data suggested transmission primarily occurred on 4 units. Timely SC, combined with targeted IC measures, were likely responsible for controlling transmission.

Carbapenem-resistant Enterobacteriaceae rectal screening during an outbreak of New Delhi metallo-ß-lactamase-producing Klebsiella pneumoniae at an acute care hospital.

We describe the results of carbapenem-resistant Enterobacteriaceae (CRE) screening as part of an outbreak investigation of New Delhi metallo-ß-lactamase-producing CRE at a tertiary care university teaching hospital. The manual method for CRE screening was useful for detecting patients with asymptomatic CRE carriage but was time-consuming and costly.