Healthcare-associated Infections

Public Health update of Carbapenem-Resistant Enterobacteriaceae (CRE) producing metallo-beta-lactamases (NDM, VIM, IMP) in the U.S. reported to CDC

Given the importance of Enterobacteriaceae in healthcare-associated infections (HAI) and the extensive antimicrobial resistance found in these strains, all types of carbapenem-resistant Enterobacteriaceae (CRE) are an important public health problem, regardless of their mechanism of resistance or their country of origin. In addition, as Enterobacteriaceae are a normal part of human flora, the potential for community-associated CRE infections also exists. Carbapenem-resistance in Enterobacteriaceae can occur by many mechanisms, including the production of a metallo-beta-lactamase (such as NDM, VIM, and IMP) or a carbapenemase (such as Klebsiella pneumoniae carbapenemase, KPC).

CDC has been working with partners to prevent CRE infections, including those caused by KPC-producing organisms, which are the most common type of CRE in the United States. The KPC gene makes Enterobacteriaceae bacteria resistant to all beta-lactam/carbapenem antibiotics. KPC producers have been reported in about 37 states and are associated with high mortality, up to 40 percent in one report. They may be present in the other 14 states as well, but have not been reported to CDC. The presence of CRE, regardless of the enzyme that produced that resistance, reinforces the need for better antibiotic stewardship, transmission prevention, and overall HAI prevention in any healthcare setting.

The detection of new mechanisms of carbapenem resistance (ie, metallo-beta-lactamases) in the United States has raised questions about the identification and control of CRE. [See laboratory protocol for detection of KPC and NDM-1 genes.] The mechanism of carbapenem-resistance is of epidemiologic interest but is not necessary for implementation of infection prevention recommendations. Current guidance for the control of all types of epidemiologically important multidrug-resistant organisms is available in the 2006 MDRO Guideline. In addition, see specific guidance for the control of CRE. These recommendations apply regardless of the resistance mechanism.

It is important to note that CRE, unlike other drug-resistant infections such as VRSA, are not a nationally reportable or notifiable disease. Therefore, there is not a requirement to report to CDC and therefore we may not know the true number of infections caused by these organisms in the US (only those voluntarily reported to CDC).

Below is a map showing states with confirmed CRE cases caused by the KPC enzyme in yellow. A blue dot represents a confirmation of CRE caused by the NDM-1 enzyme. An orange dot represents a CRE caused by a VIM or IMP enzyme.

2011 Location of Carbapenem-Resistant Enterobacteriaceae (CRE) caused by KPC enzyme; CRE caused by other enzymes noted

Carbapenem-Resistant Enterobacteriaceae map

States with confirmed CRE cases caused by the KPC enzyme.

Alabama
Arizona
Arkansas
California (CRE caused by the NDM-1 enzyme and VIM or IMP enzyme)
Colorado
Delaware Florida
Georgia
Illinois (CRE caused by the NDM-1 enzyme)
Indiana
Iowa
Kentucky
Louisiana
Maryland (CRE caused by the NDM-1 enzyme)
Massachusetts (CRE caused by the NDM-1 enzyme)
Michigan
Minnesota
Mississippi
Missouri

Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oregon
Pennsylvania
South Carolina
Tennessee
Texas
Utah
Virginia (CRE caused by the NDM-1 enzyme)
West Virginia
Wisconsin
Wyoming