Infection Control Update: The Emerging Threat of CRE

Recently there has been a great deal of focus on new diseases that have not yet reached the shores of the United States. One example is Middle East respiratory syndrome coronavirus (MERS-CoV). Healthcare workers and EMS providers have been talking about this SARS-like virus, which has only been noted in a small number of countries that does not include the United States.

On the other hand, not much has been published about another infection of great significance that has reached our shores: carbapenem-resistant Enterobacteriaceae, or CRE. CRE is important because of its high level of resistance to antibiotics. The CDC has noted this is “an emerging threat to public health.” In some circles it is referred to as the new “superbug”—a superbug that is here and has received little attention in the media or in education and training programs.

What Is CRE?

Enterobacteriaceae include common organisms such as Escherichia coli (E. coli) and Klebsiella species most commonly associated with the intestinal tract. These bacteria can spread from the GI tract, causing pneumonias and serious infections of the bloodstream, urinary tract and wounds. These infections are not just associated with healthcare facilities but are often seen in community settings as well. To date the most common type of CRE in the United States is carbapenem-resistant Klebsiella pneumoniae (CRKP). CRKP appears resistant to virtually all readily available antibiotics. Thus, patients who acquire it have a high rate of morbidity and death. About 50% of patients who have CRE infection of the bloodstream die as a result of this organism.¹

Carbapenems are a group of antibiotics that are held in reserve to treat the most serious infections, including several drug-resistant infections. CRE resistance means these reserve antibiotics are ineffective.

While CRE has been detected and reported worldwide, the CDC reports the first case in the United States was identified in a medical facility in North Carolina in 2001. Now it has been reported by facilities in 41 states. Patients have been identified with the infection after receiving previous medical treatment in such countries as Greece, Italy, India, Pakistan and Vietnam. At risk for CRE are those who have invasive devices such as intravenous or urinary catheters or have been placed on ventilators.²

Research found 3% of patients in a Chicago-area ICU carried CRE. The same study noted a 30% infection rate in long-term care facilities. Many of these patients did not exhibit any signs or symptoms of infection with this organism. The first identified outbreak of CRKP was in Detroit in 2009. This outbreak involved three different healthcare facilities.

In the U.S., before this outbreak, only 16 isolates in clusters with two or fewer cases had been identified since 2009; 14 were from patients who had received medical care in South Asian regions where this organism is often seen. The case described below is the largest U.S. outbreak of NDM-producing CRE to date. NDM, or New Delhi metallo-beta-lactamase, is an enzyme that makes bacteria resistant to a large range of beta-lactam antibiotics, including those of the carbapenem group. This illustrates the risk for spread of these organisms among persons receiving medical care inside the United States.² Evidence that undetected asymptomatically colonized patients likely contributed to the size of the outbreak highlights the importance of timely active surveillance cultures when CRE is identified to direct infection-control measures and limit further transmission.

Outbreak in Colorado

On August 16, 2012, the Colorado Department of Public Health and Environment got word of two patients at an acute-care hospital in Denver with CRE, specifically Klebsiella pneumoniae, isolated from respiratory specimens during July and August. Both isolates produced NDM. A review of microbiology records identified a third patient with NDM-producing CRKP isolated from a respiratory specimen, admitted in May. Active surveillance cultures in September identified five more patients colonized with NDM-producing CRKP. An investigation was launched by the hospital and Colorado Department of Public Health and Environment to guide infection-control measures and limit transmission.

The eight patients were aged 23–75 years and had been hospitalized at one or more of 11 different units in the hospital for a median of 18 days (range: 12–83) before CRKP identification. Three were treated for CRKP infection, and five were found to be asymptomatically colonized; none died. Initial isolates were resistant to all antimicrobials except tigecycline (Tygacil), to which all were susceptible. All isolates appeared to be related. Epidemiologic tracing to determine temporal overlap of patients in hospital units indicated multiple transmission events had occurred, and three units were likely transmission sites. But acquisition of NDM-producing CRE by some patients was not explained by direct overlap and suggested that undetected asymptomatically colonized patients were involved in some transmission routes. How NDM-producing CRE was introduced to the facility is unclear.³

Transmission Control

A superbug is here, and in some studies it remains unclear how it spreads. This reinforces the importance of three aspects of prehospital care.

First, we have become a very global society, and this means determining travel history is important. This was requested for SARS, and then for bird flu and H1N1. The writing is on the wall: Patient travel history should now be a routine part of assessment.

Second, practicing standard precautions, routine post-transport cleaning and good hand hygiene is essential. For this organism and other multi-drug-resistant organisms, contact precautions also need to be in place. Knowing how an organism may be transmitted leads to establishing infection-control measures for preventing transmission. A contact precaution incorporates the use of a cover gown into prevention measures (see the sidebar for review of contact precautions). Medical and long-term care facilities should inform EMS transport agencies when patients are on isolation precautions so these precautions can be continued during transport.^4-6

Third, stay healthy. Healthy people usually don’t get CRE infections. Don’t come to work when you are not healthy, and comply with CDC work-restriction guidelines. These are in your best interests, as well as those of your coworkers and patients. Work-restriction guidelines should be part of your department’s exposure-control plan, as well as an established component of a health and wellness program.⁷

Do We Comply?

There remains a disconnect among many healthcare providers. Many are concerned about acquiring infections from patients, yet fail to follow through on basic measures for protection. For example, during a CRKP outbreak in a hospital in 2008, surveillance noted a lack of compliance with infection control practices. Just 62% of those surveyed followed recommendations for the use of gowns and gloves; compliance with basic hand-washing was 48% even with the availability of alcohol-based hand-wash solutions.⁶ In one fire/EMS agency, 58.5% of department members said they hadn’t received any training on hand hygiene from their department.⁸ A review of articles regarding the presence of MRSA and other organisms in ambulances and on equipment suggests there is a lack of compliance with basic cleaning and disinfection after each patient transport.

This means that concern over infection risk and practices for protection are not in alignment. Departments need to conduct compliance monitoring to ensure that members follow prescribed infection-control basics. Compliance monitoring is a required component of an exposure control plan and will assist in identifying areas for education and training. Compliance should also be part of annual performance appraisals.

Drug resistance is a growing problem globally, and adherence to basic infection-prevention measures offers protection to patients as well as providers. Fire and EMS personnel need to be trained regarding the various transmission-based isolation precautions, not just standard precautions. This is especially important as we progress to community paramedicine.

APIC Tracks State Reporting of CRE Infections

The Association for Professionals in Infection Control and Epidemiology (APIC) has compiled a summary of states that have statewide reporting of the superbug carbapenem-resistant Enterobacteriaceae (CRE), one of the organisms the Centers for Disease Control and Prevention (CDC) has placed in the “urgent” category in its new report on antibiotic-resistance threats.
The APIC report summarizes how individual states are defining, tracking and reporting CRE to their state health departments.
Tracking the spread of antibiotic-resistant infections is one of the four core actions identified by the CDC to combat the serious health threat posed by antibiotic-resistant germs such as CRE.
The CDC estimates that in the United States more than two million people are sickened every year with antibiotic-resistant infections, with at least 23,000 dying as a result.
For more information, visit APIC’s Infection Prevention and You website at www.apic.org.

Microorganisms for Contact Precautions

1. Antibiotic-resistant organisms [CRE; methicillin-resistant Staphylococcus aureus (MRSA); extended-spectrum beta-lactamase (ESBL); penicillin-resistant Streptococcus pneumoniae (PRSP); multidrug-resistant Pseudomonas aeruginosa (MDRP)]

2. Scabies

3. Herpes zoster (shingles), localized

4. Diarrhea, Clostridium difficile

Maximize Your Protection

Standard Precautions

These are the measures that should be taken with all patients.

1. Wash your hands (the most important step in infection control);

2. Put on gloves before coming into contact with broken skin, mucous membranes, blood, body fluids, soiled instruments or contaminated waste materials;

3. Wash your hands again upon removal of gloves and between patients.

Contact Precautions

1. Wash your hands;

2. Put on a cover gown, then gloves.

Transporting Patients

1. Patients should perform hand hygiene and wear clean gowns;

2. For direct contact with patients, care providers should wear gowns and gloves;

3. Notify the receiving facility or EMS transport agency;

4. Clean/disinfect the areas of patient care and contact.

Before Leaving the Patient’s Room

1. Remove gloves, then gown;

2. Wash hands.

References

1. Yong D, Toleman MA, Giske CG, et al. Characterization of a new metallo-beta-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique genetic structure in Klebsiella pneumonia sequence type 14 from India. Antimicrob Agents Chemother, 2009; 53: 5,046–54.

2. Wilson ME, Chen LH. NDM-1 and the role of travel in its dissemination. Curr Infect Dis Rep, 2012; 14: 213–26.

3. CDC. Notes from the Field: Hospital Outbreak of Carbepenem-Resistant Klebsiella pneumoniae Producing New Delhi Metallo-Beta-Lactamase—Denver, Colorado, 2012. MMWR, 2013 Feb 15; 62(6): 108.

4. Siegel JD, Rhinehart E, Jackson M, Chiarello L; the Healthcare Infection Control Practices Advisory Committee. Management of Multidrug-Resistant Organisms In Healthcare Settings, 2006. CDC, www.cdc.gov/hicpac/pdf/MDRO/MDROGuideline2006.pdf.

5. CDC. Guidance for Control of Infections with Carbapenem-Resistant or Carbapenemase-Producing Enterobacteriaceae in Acute Care Facilities. MMWR, 2009 March 20; 58 (10): 256–260.

6. CDC. Guidance for Control of Carbapenem-resistant Enterobacteriaceae (CRE): 2012 CRE toolkit, https://www.cdc.gov/hai/pdfs/cre/CRE-guidance-508.pdf.

7. Shefer A, Atkinson W, Friedman C, et al. Immunization of Health-Care Personnel. MMWR, 2011 Nov 25; 60(RR07): 1–45.

8. McGuire-Wolf C, Haiduven D, Hitchcock CD. A multifaceted pilot program to promote hand hygiene at a suburban fire department. Am J Infect Control, 2012 May; 40(4): 324–7.  

Katherine West, RN, BSN, MSEd, is an infection-control consultant for Infection Control/Emerging Concepts in Manassas, VA, and a member of EMS World’s editorial advisory board.