LB-8. Evolving Epidemiology of New Delhi Metallo--Lactamase-Producing Enterobacteriaceae Reported in the United States
Session: Oral Abstract Session: Late Breaker Oral Abstracts
Saturday, October 5, 2013: 11:54 AM
Room: The Moscone Center: 102 (Gateway Ballroom)

Carbapenem-resistant Enterobacteriaceae (CRE) producing the Klebsiella pneumoniae carbapenemase (KPC) have spread widely throughout the United States; however, CRE producing other carbapenemases, such as the New Delhi metallo-β-lactamase (NDM), are more rarely reported. Patients with these organisms have frequently been exposed to healthcare outside the United States. This abstract describes the current epidemiology of the NDM-producing CRE reported to CDC


CDC receives isolates for reference confirmation of carbapenem resistance, including testing for the presence of carbapenemases. Since 2009, CDC has requested that Enterobacteriaceae suspected of metallo- β-lactamase production be submitted for confirmation. These isolates undergo phenotypic susceptibility testing for carbapenem resistance and metallo- β-lactamase production, as well as PCR for common carbapenemases. If a carbapenemase is identified, CDC works with health departments and facilities to investigate and implement infection control recommendations.

Result: As of July 1, 2013, 45 patients with 49 NDM-producing CRE have been reported to CDC from 14 states. The number reported has risen steadily each year: 2009, n=2; 2010, n=4; 2011, n=5; 2012, n=16; 2013 (through July 1), n=18. NDM-producing isolates were found among 6 different species of Enterobacteriaceae, most commonly K. pneumoniae (24/49) and Escherichia coli (21/49). The mean age of NDM patients was 60 years (range 1 to 88). The most common exposure was an overnight stay in a healthcare facility outside the United States (24/45); however, this was more commonly found in patients in 2009-2011 (10/11) than in 2012-2013 (14/34). Fifteen patients from 3 clusters in 2012-2013, likely represented transmission in U.S. healthcare facilities.


The number of NDM-producing CRE reported to CDC has increased since 2009, with a marked increase in reporting since 2012. While most cases prior to 2012 were associated with healthcare exposure outside of the United States the majority of recent cases were not, suggesting domestic transmission of NDM-producing CRE.  To prevent further emergence, aggressive infection control interventions are necessary when these organisms are identified.

Alexander Kallen, MD, MPH1, J. Kamile Rasheed, PhD1, David Lonsway, MMSc1, Tatiana Travis, BS1, Alice Guh, MD, MPH1, Brandi Limbago, PhD1 and Wendy Bamberg, MD2, (1)Division Of Healthcare Quality Promotion, Centers for Disease Control and Prevention, Atlanta, GA, (2)Colorado Dept. of Public Health and Environment, Denver, CO


A. Kallen, None

J. K. Rasheed, None

D. Lonsway, None

T. Travis, None

A. Guh, None

B. Limbago, None

<< Previous Abstract | Next Abstract

Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.