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North Carolina Guidelines for Control of Antibiotic Resistant Organisms, Specifically Methicillin-Resistant Staphylococcus aureus (MRSA) and Vancomycin-Resistant Enterococci (VRE)

I. INTRODUCTION

This policy outlines recommendations for control measures to prevent the spread of antibiotic-resistant organisms, specifically methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), in healthcare settings including acute care hospitals, long term care (LTC) facilities, rehabilitation facilities, psychiatric facilities, hospice, home health care, and other settings in which people colonized or infected with resistant organisms may receive care. Although these guidelines do not encompass the whole body of knowledge on the subject, MRSA and VRE are currently the most important examples and represent the larger problem of resistant organisms which requires application of the basic principles of infection control.

II. BACKGROUND

A. Methicillin-Resistant Staphylococcus aureus

In the United States and North Carolina MRSA strains have been identified as a major source of nosocomial infections and outbreaks. For three decades MRSA has presented a challenge for infection control departments of university-affiliated and community teaching hospitals attempting to control and eradicate it. Long term care facilities, rehabilitation centers and small community hospitals are seeing increasing numbers of cases. These facilities experience continuous reintroduction of resistant organisms because of the recurrent admissions of patients to these settings. MRSA accounts for 12% of all nosocomial infections in the US; resistance to methicillin increased from 2.4% in 1975 to 29% in 1991.

Staphylococcus aureus is ubiquitous. It grows readily on human skin and mucous membranes. Methicillin-resistant S. aureus is a variant of S. aureus which is resistant to all beta-lactam antibiotics (including penicillins, cephalosporins and cephamicins). They may also be resistant to aminoglycosides, erythromycin, quinolones and others. By definition, MRSA must be resistant to one of the following semi-synthetic penicillins: methicillin, oxacillin, or nafcillin. MRSA is neither more infectious nor more virulent than susceptible S. aureus; it is just more difficult to treat. MRSA infections are most effectively treated with intravenous vancomycin.

B. Vancomycin-Resistant Enterococci

A rapid increase in the incidence of infection and colonization with vancomycin-resistant enterococci (VRE) has been reported from US hospitals from 1989 through 1993 (from 0.3% to 7.9%). The increase was due mainly to the 34-fold rise, from 0.4% to 13.6%, of VRE infections in intensive-care unit (ICU) patients, although a trend was also noted in non-ICU patients. The occurrence of VRE in National Nosocomial Infections Surveillance System (NNIS) hospitals was associated with larger hospital size (200 or more beds) and university affiliation. Other hospitals have also reported increases in endemic rates and clusters of VRE colonization and infection. This increase poses several problems, including the lack of available antimicrobials for therapy, since most VRE are also resistant to multiple other drugs (e.g., aminoglycosides and ampicillin) previously used for the treatment of infections due to these organisms. In addition, there is the possibility that the vancomycin-resistant gene (VAN A gene) present in VRE may be transmitted to other gram positive organisms, such as S. aureus. Like MRSA, VRE is neither more infectious nor more virulent than susceptible enterococci, but it is a challenge because treatment options are limited to combinations of antimicrobials or experimental compounds with unproven efficacy.

III. COLONIZATION VS. INFECTION

A. Colonization is the presence, growth, and multiplication of the organism without observable clinical symptoms or immune reaction.

1.MRSA - Colonization may occur in the nares, axillae, chronic wounds or decubitus ulcer surface, perineum, around gastrostomy and tracheostomy sites, in the sputum or urine. One of the most common sites of colonization in both patients and employees is the nose (anterior nares). While personnel may become colonized with MRSA (as they may with susceptible S. aureus), they rarely develop infections.

2.Enterococci are normally found in the bowel and the female genital tract. When exposed to antibiotics for any reason, the drug-resistant bacteria may survive and multiply, resulting in an overgrowth of drug-resistant enterococci in the bowel, referred to as colonization.

B.Infection refers to invasion of bacteria into tissue with replication of the organism. Infection is characterized by isolation of the organism accompanied by clinical signs of illness such as either fever, elevated white blood count, purulence (pus), pneumonia, inflammation (warmth, redness, swelling), etc.

IV. EPIDEMIOLOGY

A. Methicillin-Resistant Staphylococcus aureus

1. Mode of Transmission - MRSA is transmitted primarily by contact with a person who either has a purulent site of infection, a clinical infection of the respiratory tract or urinary tract, or is colonized with the organism. Hands of personnel appear to be the most likely mode of transmission of MRSA from patient-to-patient. Studies have demonstrated that MRSA can be present on the hands of personnel after performing such activities as wound debridement, dressing changes, tracheal suctioning, and catheter care.

2. Reservoirs - Colonized and infected patients are the major reservoir of MRSA. MRSA has been isolated from environmental surfaces including floors, sinks, and work areas, tourniquets used for blood drawing, and blood pressure cuffs. Although MRSA has been isolated from environmental surfaces (e.g., floors, medical equipment), these are not the most likely source of spread. However, environmental surfaces should be disinfected routinely to reduce the bacterial load.

3.Risk Factors - The factors that have been identified as increasing the risk that a patient will have a MRSA infection are:

a. Increased length of hospital stay

b. Multiple hospitalizations

c. Greater than 65 years old

d. Multiple invasive procedures

e. Wounds

f. Severe underlying disease

g. Administration of broad-spectrum antibiotics

Among hospitalized patients who acquire MRSA colonization, 30-60% eventually will develop a MRSA infection such as a wound infection, bacteremia, urinary tract infection, or pneumonia. However, unlike hospitalized patients, only 5-15% of residents in LTC facilities who acquire MRSA colonization subsequently will develop MRSA infections. Studies have indicated that roommate-to-roommate transmission of MRSA in LTC facilities appears to be uncommon.

B. Vancomycin-Resistant Enterococci

1. Mode of Transmission - Recent reports have demonstrated that enterococci, including VRE, can spread patient-to-patient by direct contact via transient carriage on the hands of personnel or indirectly on contaminated environmental surfaces and patient care equipment.

2.Reservoirs of VRE - Enterococci are part of the normal flora of the gastrointestinal tract and female genitourinary tracts. Most infections with these microorganisms have been attributed to the patient's endogenous flora. However, a recent study found VRE is capable of prolonged survival on hands, gloves, and environmental surfaces. E. faecalis was recovered from countertops for 5 days; the E. faecium persisted for 7 days. Thus environmental surfaces may serve as potential reservoirs for nosocomial transmission of VRE and need to be considered when formulating institutional infection control policies.

3.Risk Factors - The epidemiology of VRE has not been elucidated completely; however, certain patient populations have been found to be at increased risk for VRE infection or colonization. This includes patients who:

a. Are critically ill

b. Have severe underlying disease or immune suppression (such as ICU patients or patients in oncology or transplant wards)

c. Have had an intra-abdominal or cardio-thoracic surgical procedure

d. Have an indwelling urinary or central venous catheter

e. Have had a prolonged hospital stay

f. Have broad spectrum antimicrobial therapy

g. Have received administration of oral and, to a lesser extent intravenous (IV), vancomycin

V. CONTROL MEASURES

A. General Control Measures

1. Infection Control Plan - It is recommended that every facility develop a comprehensive, institution-specific, strategic plan to detect,prevent, and control infection and colonization with multiple- antibiotic-resistant organisms. The plan should include controls to minimize unnecessary antibiotic use in all patients and methods to insure the prudent use of vancomycin for strictly appropriate indications (see Attachment A).

2. Handwashing - Healthcare workers should be required to wash their hands for at least 10 seconds before leaving a patient room whether or not gloves were worn. The indications for handwashing are specified in the "APIC Guideline for Handwashing and Hand Antisepsis in Health Care Settings." Various antimicrobial handwashing products, including waterless alcohol-based antiseptic agents, have been strongly recommended by experts as a way to help prevent cross-transmission in acute care facilities. These products should be considered by other facilities as well. It should be noted that bland soap has been shown to be relatively ineffective in removing VRE from the hands.

3. Communication

a. It is the responsibility of the facility transferring the patient to inform a receiving facility and the ambulance squad of the patient's colonization or infection history and status prior to treatment or transfer.

b. A receiving facility that finds that a patient admitted from another institution is infected or colonized with a multiple-antibiotic-resistant organism within 48 hours of admission should inform the transferring institution.

c. It is important that healthcare workers who may have direct contact with patients on transmission-based precautions be made aware of appropriate control measures (e.g., protective garments/barriers) prior to room entry. Traditionally this has been accomplished by placing instructional cards on the patient's door and a label on the patient care record.

d. If special precautions are used for patients colonized/infected with multiple-antibiotic-resistant organisms, identifying such persons at the time of readmission to the facility can assist the admissions department and nursing personnel to implement special precautions promptly. This measure requires some indication in the patient's medical record and/or computer file, which is accessed at the time of admission. Use of a system that maintains patient confidentiality is essential.

4. Standard Precautions (Attachment B) should be practiced for contact with every patient. The term Standard Precautions is defined in "Guideline for Isolation Precautions in Hospitals," published in 1996, and is not the same as Universal Precautions.

5. Decolonization Therapy - Decolonization is the use of antibiotics to treat colonized patients for the purpose of reducing the magnitude of the reservoir.

a. Patients
(1) MRSA - Routine decolonization for MRSA is not recommended. The need for decolonization should be based on the patient's medical condition and expected outcome. Topical or systemic antibiotics, including trimethoprim-sulfamethoxazole, rifampin, ciprofloxacin, erythromycin, doxycycline, bacitracin and mupirocin have been used with variable results to eradicate colonization by MRSA. Vancomycin is not indicated for decolonization therapy, as it is ineffective for this purpose.

(2) VRE -There is no clinically proven decolonization regimen for VRE.

b. Employees
(1) MRSA - Healthcare personnel should be cultured only if epidemiologic data implicates them (e.g., by geographic location or patient care team) as a possible source of dissemination of MRSA. Identified infected personnel with hand or skin lesions should be treated. Decolonization should be considered for those employees with persistent MRSA nasal carriage (e.g., chronic sinusitis), especially if the healthcare worker had contact with patients who were subsequently found to be positive for the same strains. Intranasal mupirocin appears to be an effective agent for eradicating nasal carriage of MRSA; prolonged therapy should be discouraged.

(2) VRE - Carriers of enterococci have been rarely implicated in transmission of this organism. For facilities with continued VRE cross-transmission, see Attachment C.

6. Education
a. Personnel - Continuing education programs for healthcare workers who have direct patient contact or who are responsible for decision making regarding patient care should include a thorough review of the information presented in this guideline.

b. Patient Education - Patient education is essential to control the transmission of infections. Patients should be instructed to cover their mouths when coughing and practice good handwashing. They should not share drinks or food. Personal items such as games, books, or computers should be cleaned with an EPA-approved disinfectant before sharing with another patient. Patients on isolation and their families need additional education, including the reason for isolation, control measures, and expected duration of isolation.

7. Visitors - Visitors should be instructed that items are not to be shared between patients unless they can be appropriately cleaned. When visiting patients on Contact Precautions, visitors should be instructed regarding control measures, with special emphasis on handwashing.

8. Surveillance - Culture and susceptibility data should be reviewed routinely to detect MRSA and VRE, and a line listing of MRSA and VRE cases (infection or colonization) should be maintained. It should be noted whether cases are nosocomial, community-acquired, or transferred from another facility. This information may be used to establish a baseline or endemic rate for the facility. If continual cross-transmission occurs or an outbreak is recognized, additional surveillance techniques may be appropriate. An outbreak is defined as an excess over the expected (usual) level of a disease within a geographic area (e.g., hospital). Guidance in outbreak situations may be obtained by calling the Statewide Infection Control Program (919-966-3242).

As stated in the Centers for Disease Control and Prevention (CDC) "Guideline for Isolation Precautions in Hospitals," no guidelines can address all the needs of the many kinds of facilities serving different patient populations.

1. Acute Care Facilities ideally should follow the CDC "Guideline for Isolation Precautions in Hospitals," making modifications according to what is possible, practical and prudent.

The recommendations are intended primarily for use in the care of patients in acute-care hospitals, although some of the recommendations may be applicable for some patients receiving care in subacute-care or extended-care facilities. (See Attachment D.)

2. Long Term Care Facilities

a. Admission - Admission to licensed facilities should not be denied on the basis of colonization or infection with multiple-antibiotic-resistant organisms.

b. Activities - In general, residents colonized or infected with multiple-antibiotic-resistant organisms may use common living areas, recreational areas, and dining facilities. Patients leaving their rooms for activities should have clean, dry dressings and wear clean clothes or a clean cover gown. If necessary, their hands must be washed for them whenever they may be contaminated and before they leave their rooms for common areas. In addition to the above requirements, the VRE colonized or infected patient should be continent of stool.

c. Contact Precautions - The implementation of Contact Precautions in addition to Standard Precautions should be based upon the site and severity of infection. Other factors to consider include the resident's mental status, reliability, personal hygiene, the ability to contain wound drainage, and whether the patient who is colonized in the respiratory tract has a cough.

(1) Standard Precautions are adequate for
(a) The patient who is nasally or superficially colonized (e.g., identified from sputum culture, but without purulence) with MRSA.

(b) The VRE patient who is colonized in the gastrointestinal tract and continent of stool and capable of maintaining hygienic practices (e.g., handwashing).

(2) Indications for Contact Precautions

(a) Patients who should be placed on Contact Precautions include the following.
(i) Patients with foley catheter-associated MRSA or VRE urinary tract infection or colonization.

(ii) Patients with wounds heavily colonized or infected with MRSA or VRE.

(iii) Patients with a tracheostomy who have a colonized or infected respiratory tract and who are unable to handle secretions.

(b) When a cluster of nosocomial (institutionally acquired) infections is recognized, then Contact Precautions should be instituted for all identified cases.

(3) Room Placement for Patients on Contact Precautions

(a) Ideally, the patient on Contact Precautions should be placed in a private room.

(b) When a private room is not available, the patient may be placed in a room with a patient(s) who has the same microorganism, but no other infection or colonization with a different multiple-antibiotic-resistant organism (cohorting).

(c) If a private room is unavailable and cohorting cannot be accomplished, then the patient may be placed in a room with another patient. The best roommate for a person with MRSA or VRE is a patient who:

(i) Has intact skin

(ii) Has no invasive devices (no nasogastric tubes, tracheostomy or tracheal tube, no IV lines, no foley catheters, etc.)

(iii) Is not significantly immunocompromised (e.g., neutropenic, on oral steroids, or on chemotherapy).

(4) Gloves

(a) In addition to wearing gloves as outined under Standard Precautions, wear gloves (clean, single-use, non-sterile gloves are adequate) when providing direct patient care or handling items potentially contaminated by the patient on Contact Precautions.

(b) During the course of providing care for a patient, change gloves after having contact with infected material that may contain high concentrations of microorganisms (e.g., fecal material and wound drainage).

(c) Remove gloves before leaving the patient's environment, and wash hands immediately. After glove removal and handwashing, ensure hands do not touch potentially contaminated environmental surfaces or items in the patient's room to avoid transfer of microorganisms to other patients or environments.

(5) Gowns

(a) In addition to wearing a gown as outlined under Standard Precautions, wear a gown (a clean, non-sterile gown is adequate) for the patient on Contact Precautions when doing direct patient care or if you anticipate that your clothing will have substantial contact with the patient, environmental surfaces, or items in the patient's room, or if the patient is incontinent or has diarrhea, an ileostomy, a colostomy, or wound drainage not contained by a dressing.

(b) Remove the gown before leaving the patient's environment. After gown removal, ensure that clothing does not contact potentially contaminated environmental surfaces in order to avoid transfer of microorganisms to other patients or environments.

(6) Masks - Masks should be worn as specified in Standard Precautions.

(7) Patient-Care Equipment

(a) When possible, dedicate the use of non-critical patient care equipment (equipment which comes into contact only with intact skin) to a single patient (or cohort of patients infected or colonized with the pathogen requiring precautions) to avoid sharing between patients.

(b) Electronic thermometers used with the VRE patient should not be shared with other patients. Dedicate a thermometer for single patient use and disinfect when the patient is removed from Contact Precautions.

(c) If use of common equipment or items is unavoidable, then adequately clean and disinfect them before use for another patient.

(8) Linen and Laundry - Special handling (i.e., double bagging) of isolation linens is not recommended. (See Attachment B for further information).

(9) Isolation Room Solid Waste - Special handling (i.e., double bagging) of isolation room solid waste is not recommended. Follow your institutional policy for waste management.

(10) Dishes, Glasses, Cups, and Eating Utensils - No special precautions are needed for dishes, glasses, cups, or eating utensils. The combination of hot water and detergents used in institutional dishwashers is sufficient to decontaminate these items.

(11) Routine and Terminal Cleaning - The room and bedside equipment of patients on Contact Precautions are cleaned using the same procedures used for all patients in accordance with Standard Precautions. Multiple-antibiotic-resistant organisms are as susceptible to disinfectants as antibiotic-sensitive strains.

(12) Termination of Precautions

(a) MRSA - A patient with MRSA may be taken off Contact Precautions after two cultures taken 24 hours apart are found to be negative for MRSA. These cultures should be taken from each previously infected or colonized site and from the anterior nares. These cultures should be taken at least 48-72 hours after antibiotics used for treatment have been discontinued.

(b) VRE - For the VRE patient, Contact Precautions may be discontinued when three successive negative cultures (stool cultures and initial site of infection/colonization) obtained at least one week apart are reported. These cultures should be taken at least 48-72 hours after antibiotics used for treatment have been discontinued.

In addition to Standard Precautions (Attachment B), healthcare personnel providing care in the home should follow the recommended practices for Contact Precautions as described by the CDC for acute care facilities. (See Attachment D, paragraphs B, C, and E.) Specifically, home healthcare workers should focus on preventing cross-transmission via the clinical bag, clothing, and equipment which is carried to and from the home by the healthcare professional. Alternatively, the clinical bag may be left in the vehicle and only the disposable items used for the patient be carried into the home. Reusable equipment must be cleaned either in the patient's home or bagged prior to returning to the clinician's vehicle or facility for disinfection. Hands should be washed before leaving the home.

Standard Precautions should be used for all patients. Waiting areas should be screened for patients with productive coughs, draining wounds or other signs and symptoms of infection. Patients exhibiting such symptoms should be removed from the waiting area to an exam room as soon as possible. Once a patient has been identified with a multiple-antibiotic-resistant organism, subsequent visits to the office/clinic should be managed carefully. Any surfaces which may have had contact with the patient (e.g., blood pressure cuffs, examination table, stethoscopes) should be cleaned with an EPA-registered disinfectant prior to use for another patient. (See Attachment D, Paragraphs B and C for information about the proper use of gloves and gowns.) For guidelines on handling linen and laundry and isolation room solid waste, see Attachment B, Section G - Linen.

In addition to Standard Precautions, follow the Long Term Care recommendations in this guideline. Students identified with multiple-antibiotic-resistant organisms should be instructed regarding how to prevent contamination of school materials that are to be reused by others (e.g., cover cough, wash hands prior to using school materials). Shared items such as books and computer keyboards must be cleaned with an EPA-registered disinfectant prior to use by another individual. When possible, these items should be assigned to the student who is on Contact Precautions as long as the person requires the items, and then cleaned and disinfected prior to reuse by another student.

Admission should not be denied on the basis of colonization with multiple-antibiotic-resistant organisms. These patients are usually ambulatory and not bed-bound. Since these patients require minimal assistance with activities of daily living and have few invasive devices (e.g., foley catheters), additional precautions beyond Standard Precautions are unnecessary unless a cluster of facility-acquired infections is recognized. Handwashing education should be emphasized in employee and staff education. Consult the Statewide Infection Control Program (919-966-3242) if a cluster is recognized.

This patient population is generally not immunocompromised; thus, the risk of colonization with multiple-antibiotic-resistant organisms progressing to infection is less than for patients in acute care facilities. These patients are unique in that they are learning to manage their own care (e.g., wound, foley). Handwashing and the use of barrier techniques should be included in patient education. In addition to Standard Precautions, the Long Term Care recommendations in this guideline should be followed. Consult the Statewide Infection Control Program (919-966-3242) if a cluster is recognized.

These patients typically have no underlying medical conditions increasing their risk of infection. These facilities are unique in that the patients are encouraged to join in group activities, and they may eat in a common dining room. All these activities are important for their treatment regimen. To isolate or cohort ambulatory patients with MRSA would be contrary to the philosophy and policy of most of these facilities. However, patients with underlying medical conditions should be evaluated on a case by case basis for the risk of contaminating their environment if infected with MRSA or VRE. Those patients who cannot comply may need to be transferred. Consult the Statewide Infection Control Program (919-966-3242) if a cluster is recognized.

The patients colonized or infected with multiple-antibiotic-resistant organisms require no special control measures beyond regularly cleaning all surfaces contaminated by secretions or touched by hands . Family members should inform healthcare facilities or providers of the patients' prior colonization or infection with multiple-antibiotic-resistant organisms.Family members should perform handwashing with an antibacterial soap for a minimum of 10 seconds after direct contact with the patient or any items the patient has touched, before preparing food and before eating. The patient and caregiver should wash hands after using the toilet.

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