by Kristin Sullivan, M.P.H.
Carbapenem-resistant Enterobacteriaceae (CRE) are a growing public health concern and the current topic of CDC’s Vital Signs campaign (http://www.cdc.gov/vitalsigns/HAI/CRE/index.html). These organisms are associated with high mortality rates and have the potential to spread widely through transmissible gene segments. Although CRE prevalence is on the rise, the opportunity still exists to prevent widespread transmission.
In the United States, the most common
mechanism of carbapenem resistance is the Klebsiella
pneumoniae carbapenemase (KPC), which was first identified in North
Carolina in 2001. Although KPC-producing
strains of CRE have been identified in our state, other unusual strains with less
common resistance mechanisms such as New Delhi metallo-β-lactamase (NDM),
Verona integrin-encoded metallo-β-lactamase (VIM), and the imipenemase (IMP)
metallo-β-lactamases have not been
reported in North Carolina. These unusual strains have been found primarily among
patients who received overnight medical treatment outside the United States.
In order to prevent the spread of KPC,
as well as to detect and prevent the emergence of unusual forms of CRE, a
coordinated, regional effort among providers, healthcare facilities and public
health is necessary.
Hospital Surveys. In order to estimate the prevalence
of CRE in our state, the North Carolina Division of Public Health (NC DPH) and
the North Carolina Statewide Program for Infection Control and Epidemiology (NC
SPICE) requested that hospital infection preventionists (IPs) and hospital
laboratories provide basic information regarding identification of and response
to CRE in their facilities. In July 2012, surveys were sent with questions
covering the time period from January 2011-June 2012. The surveys were
specifically developed to determine 1) the frequency of CRE identification in
NC, 2) current practices for detecting CRE and 3) current practices used to
prevent transmission.
Preliminary Results. Eighty-seven eligible short-stay,
acute-care hospitals were included in the survey analysis. Survey responses were received from IPs at
68/87 (78%) hospitals and from microbiology labs serving 57/87 (66%) of these hospitals.
Responses were analyzed on the state and regional level using the 6 geographic
regions defined by the North Carolina Hospital Association.
1. Frequency of CRE identification. CRE were identified in all six regions
within North Carolina during the survey period. At least one patient with CRE
infection or colonization was identified in approximately half of hospitals
completing the IP survey. CRE were
identified less frequently than once per
month in the majority of facilities. Given these findings, all regions in
North Carolina can be classified as "regions with few CRE identified"
using criteria established by CDC and outlined in the 2012 CRE Toolkit.
2.
Current
practices for detecting CRE.
Laboratories were asked to report current methods used to identify CRE, use of
interpretive criteria and future expected capabilities for CRE detection. The majority of responding laboratories
indicated the use of automated MIC systems, followed by screening using
automated susceptibility testing and the Modified Hodge Test. At the time of
the survey, fewer than 25% of laboratories reported adopting the new January
2012 breakpoints for carbapenems or cephalosporins. Approximately 40% of laboratories
not using the new breakpoints indicated that they were planning to do so within
the next year.
Less than 10% of hospitals reported
having ever conducted point prevalence surveys for CRE in high-risk units
(e.g., intensive care units or units with high antimicrobial use) or performing
active surveillance for patients with known risk factors (e.g., admission or
transfer from an area with high prevalence of CRE). Nineteen facilities (28%)
reported that they had performed a review of microbiology records to identify
previously unrecognized CRE cases.
3.
Current
practices used to prevent transmission. The most frequently reported prevention strategies used
when a CRE colonized or infected patient was identified included: placing the
patient on contact precautions (97%), placing the patient in a single-patient
room when possible (84%) and enhancing hand hygiene practices (68%). Facilities
often reported implementing more than one measure.
The inter-facility sharing of patients
colonized or infected with CRE has the potential to facilitate transmission of
CRE. Ninety-seven percent of facilities reported always or sometimes
communicating CRE status to the receiving facility when CRE-infected or
-colonized patients are transferred out of the hospital. However, only 16% of facilities
reported ever inquiring about the CRE status of incoming patients.
Conclusions. Survey results indicate that CRE are present
in all regions of North Carolina but is still identified infrequently in most
facilities. To prevent these organisms from becoming more widespread, providers,
healthcare facilities and public health entities must all recognize them as
epidemiologically important and engage in coordinated control efforts.
Baseline information from this survey
will help partners better understand the epidemiology of CRE in North Carolina
and better tailor strategies to minimize transmission. The 2012 CRE Toolkit
provides detailed guidance for the detection and prevention of CRE at the
facility and regional levels. Public health professionals, infection
preventionists and other stakeholders should familiarize themselves with this
document and ensure that appropriate measures are in place to control the
spread of CRE within and among facilities.
CRE infections can be prevented using
the guidelines outlined in the toolkit. Strict
adherence to recommended procedures will allow us to take advantage of this
unique opportunity to control the spread of this multi-drug resistant organism
before it becomes widespread in North Carolina.
For more information about CRE, please
visit the NC Healthcare-Associated Infections website at: http://epi.publichealth.nc.gov/cd/hai/providers.html.
