1. Myers, Frank Edward III MA, CIC

Article Content

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen both inside the hospital and within the community. Many studies have shown that it increases morbidity and mortality when compared with its less drug-resistant relative-methicillin-sensitive S. aureus. The literature and guidelines are divided into two very different approaches for the best use of healthcare resources to minimize transmission of the organism. After years of debate, a national consensus on best practices is building; unfortunately, it appears to be at odds with many state legislature mandates. The good news is that these universal infection prevention strategies, when followed, may not only reduce MRSA transmission rates, but also the spread of other healthcare-associated pathogens.

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A history of resistance

Since the 1970s, cyclical increases in S. aureus infection have been noted in communities and hospitals. During the outbreak of S. aureus in North America in the 1950s and 1960s, it was firmly established as a healthcare-associated pathogen. MRSA was first identified in 1961, 2 years after methicillin was approved for treatment of S. aureus infection. MRSA infection rates continued to increase slowly but steadily in North America through the 1970s and 1980s. Regional variation in North America existed; certain areas had much higher rates of infection than others. By the late 1990s, MRSA infection reached epidemic proportions.


The MRSA epidemic of the late 1990s and early 2000s wasn't driven by an increase in healthcare transmission or sicker inpatients getting infected, but by a strain of MRSA that developed resistance to treatment-originally called community-associated MRSA. This name was discontinued after it was shown that, in some cases, the community strain and the healthcare-associated strain (albeit rarely) were both being transmitted in the community.1 The new strain became known as USA300. Despite headlines in the popular press, this strain didn't "escape" from hospitals; it developed independently in the community.2


The contact precautions conundrum

As press coverage of the outbreak gained in prominence, the search for answers became more pressing. There was a broad consensus that contact precautions for MRSA infections were necessary. This approach is still supported by the Healthcare Infection Control Practices Advisory Committee (HICPAC) guidelines, commonly known as the CDC guidelines.3 Contact precautions allow for a wide range of practice by facilities. However, questions surrounding the implementation of contact precautions still exist. This is, in part, because contact precautions have been associated with several negative outcomes. (See Table 1.)

Table 1: Contact pre... - Click to enlarge in new windowTable 1: Contact precautions review

Some studies have demonstrated that healthcare workers, including attending physicians, are half as likely to enter the rooms of (or examine) patients on contact precautions.4-6 Studies have also reported that patients in private rooms and on barrier precautions for a multidrug-resistant organism (MDRO), including MRSA, have increased anxiety and depression scores.7 A number of patients in other studies have reported significantly more preventable adverse events, greater dissatisfaction with their treatment, and less documented care than control patients who aren't in isolation.8,9 Other negative outcomes of contact precautions include the cost of personal protective equipment (PPE) and longer ED wait times.10 It's also been noted in the literature that patients on contact precautions have higher acquisition rates of other MDROs.11


According to the HICPAC guidelines, institutions are encouraged to develop their own strategies for MRSA colonized and/or infected patients. Some institutions require gowning and gloving for all staff entering the room of a patient on contact precautions for easier evaluation of staff adherence. Other institutions require gowning only when contact with the patient is expected or only in certain areas of the patient's room. This approach minimizes the costs of PPE. Ironically, in most cases, hand hygiene doesn't appear to increase in contact precaution rooms compared with noncontact precautions rooms.12


Active surveillance testing

After this point of theoretical, if not functional, agreement on the use of contact precautions for patients with MRSA, vigorous academic debate focused on other best practices, such as active surveillance testing (AST)-the screening of patients for MRSA on admittance, usually via nasal cultures. Some facilities targeted patients perceived to be at highest risk for MRSA, whereas others performed AST on all patients entering the facility. Through this method, additional patients with MRSA colonization can be identified and placed on contact precautions, which theoretically reduces MRSA transmission.


The Netherlands and other Scandinavian countries adopted this "search and destroy" approach to MRSA and had very low MRSA infection rates compared with nations that weren't using AST.13 A study of AST use in a large number of U.S. facilities was conducted and the results also indicated MRSA reduction.14 In 2003, the Society for Healthcare Epidemiology of America (SHEA) issued guidelines recommending AST for detecting MRSA.13


Some facilities embraced AST as a best practice; others pointed to deficiencies published in the literature, noting that MRSA occurred more often in settings where AST was practiced. Still others discussed the increased costs associated with the additional testing. In 1 weeks' time, two contradictory articles on AST were published in high-impact medical journals.15,16 But the preponderance of data was slowly building on one side of the argument.


In 2008, an article appeared in the SHEA journal condemning AST as a flawed infection control response.17 The authors noted that focusing on a single organism (MRSA) prevented far fewer healthcare-associated infections (HAIs) than did broader infection prevention approaches. The article discussed targeted approaches (AST for MRSA) versus universal approaches (such as central line insertion practice checklists) that impacted all infections related to a device or procedure. For example, reducing central line-associated bloodstream infections (CLABSIs) by 12.5% is the equivalent of reducing MRSA infections by 50%. A 25% reduction in CLABSIs would be equivalent to eliminating all MRSA infections. This population-based argument suggested that a new, broader approach was needed to handle MRSA as one of a number of pathogens rather than as an independent problem causing HAIs.


One of many

At the same time, MRSA's role as the major healthcare-associated pathogen was being reexamined. In 2009, an article was published in JAMA showing that, contrary to public perception, MRSA had been in decline as a cause of CLABSIs since 2001.18 This was 2 years before any professional society suggested AST and around the same time that the CDC published its hand hygiene guidelines that supported the use of alcohol-based hand sanitizers in healthcare, a much broader approach to controlling HAIs. Recent data suggest that MRSA infections are becoming even rarer; a CDC analysis reported that invasive MRSA infections in the United States have dropped from an estimated 111,000 cases in 2005 to 82,000 in 2010.19


Recently, a three-armed study demonstrated the superiority of a universal approach to infection prevention by reducing all infections, including MRSA. The REDUCE MRSA Trial was conducted on 74 adult ICUs in 43 hospitals. In this study, participants were assigned to one of three arms.20 Arm one included AST followed by contact precautions if the patient's screening was positive for MRSA. Arm two was AST followed by contact precautions if the patient's screening was positive for MRSA, decolonization with mupirocin in the nose, and chlorhexidine gluconate (CHG) baths using a CHG cloth for 5 days. Arm three had no AST but every patient was given the decolonization regimen of mupirocin in the nose and daily CHG baths for the duration of their stay. Arm three showed a greater reduction in ICU-attributed MRSA clinical cultures and an overall reduction in ICU-attributed CLABSIs than the other two arms.


This information, combined with the increasing prevalence of Clostridium difficile and multidrug-resistant Gram-negative rods, reveals that best practice should include a push toward a universal infection control approach for dealing with all HAIs.


Universal infection prevention

Universal approaches that are best supported by the current literature can be broken into five groupings:


* bundles


* environmental cleaning


* patient hygiene


* healthcare worker hand hygiene


* antimicrobial stewardship.




Bundles have gained visibility in the last few years. A bundle is an approach of implementing a number of interventions aimed at reducing a problem, such as reducing CLABSIs. These bundles can be introduced in a fashion that will allow a practitioner to create a checklist so that he or she may check off his or her compliance with these interventions and permit others to validate compliance with the intervention, allowing for both process (compliance with bundle) and outcome measures (infections).


Now that the Centers for Medicare and Medicaid Services links reimbursement to bundles, such as the Surgical Care Improvement Project and central line insertion bundle, most institutions are very familiar with these approaches. Some institutions, however, are less familiar with the bundle designed to reduce catheter-associated urinary tract infections. This bundle focuses on removing unnecessary catheters, performing routine perioperative care, securing the catheter, maintaining a closed system, and keeping the bag off the floor and below the patient's bladder.21 Other bundles have been developed to reduce late onset CLABSIs (catheter maintenance bundles) by focusing on removing the line as soon as possible (usually by verifying daily line necessity), scrubbing the hub before accessing a line, covering the site with a dressing, and changing the dressing every 7 days or as needed.


Complying with the ventilator-associated pneumonia (VAP) bundle is another way to reduce MRSA and other HAIs. The VAP bundle focuses on removing the patient from the ventilator as soon as possible (usually by encouraging daily assessment for readiness to extubate), reducing sedation for a period during the day, elevating the head of the bed between 30 degrees and 45 degrees, and performing daily CHG oral care. It should be noted that one area of the original Institute for Healthcare Improvement VAP bundle, which uses H2 blockers and proton pump inhibitors to prevent peptic ulcer disease, is controversial because it may increase the likelihood of the patient developing C. difficile.22


Environmental cleaning

Occupying a room that previously housed a patient with MRSA or another MDRO is a known risk factor for acquiring that bacteria.23 Recently, studies have shown that rooms are cleaned much less than previously thought; one study noted that at over 40 hospitals, less than half of the high-touch surfaces in a patient's room were cleaned.24 The authors also discovered that, until recently, we had no way of knowing whether something was actually clean.


The use of novel technology, such as luminescent gel or powder, has given us the ability to see if items have been wiped with sufficient friction to remove bioburden. When this technology is used, environmental cleaning markedly improves.25 It has also been shown to be an effective teaching method for environmental service staff learning how and what to clean. It's widely thought that this technology should also be used for training and evaluating nursing staff members because they're frequently assigned cleaning responsibilities for patient-care equipment. In addition, clear roles about who cleans what on a patient-care unit need to be defined and reviewed with all staff on a regular basis.


Although novel technologies, such as UV light and hydrogen peroxide plasma, have shown some promise in preventing MRSA and other HAIs, they still require a staff member to preclean a room. Additionally, the data aren't definitive regarding effectiveness, revealing that some technologies pose safety challenges and delays in room turnaround, which prolongs patients' stay in EDs where inappropriate cleaning and hand hygiene challenges are significant.


Patient hygiene

Patient hygiene is becoming an increasing focus for preventing the transmission of MRSA and other HAIs. The data to date have focused primarily, but not exclusively, on patients in the ICU and the use of CHG. As shown in the REDUCE MRSA Trial, MRSA and other HAI rates can decrease significantly when the patient is bathed daily. However, it should be noted that there are disparities in the literature; some studies have shown that CHG with bath basins fails to reduce MRSA, whereas others have shown success with CHG.26,27


Nevertheless, given the repeated studies in different acute care settings demonstrating reduction in at least some HAIs (MRSA, C. difficile, CLABSIs, surgical site infections, and vancomycin-resistant enterococci) with CHG use and the marginal adverse reactions of such an approach, there's little rationale for not implementing it.


Healthcare worker hand hygiene

Hand hygiene has been recognized as an important step toward interrupting disease transmission. Studies have also been conducted that show increasing hand hygiene has reduced MRSA transmission on a unit.28,29 Unfortunately, very little data have been produced that demonstrate the ability to gain and maintain 100% hand hygiene adherence.


However, in the past few years, new technologies have been developed that allow for reminders and evaluation of healthcare worker hand hygiene at specific times, such as upon entering and exiting a patient's room. These products, although not infallible, allow unbiased and constant evaluation of units or, in some cases, specific healthcare worker hand hygiene adherence. This technology is promising but hasn't yet gained wide usage in acute care settings.


Antimicrobial stewardship

Antimicrobial stewardship has been noted to be an effective way to control MRSA and other MDROs.30 Antimicrobial stewardship is "a set of coordinated strategies to improve the use of antimicrobial medications with the goal of enhancing patient health outcomes, reducing resistance to antibiotics, and decreasing unnecessary costs."31 In fact, the early literature supporting AST for reducing MRSA at one institution was mirrored by claims that antibiotic controls had also reduced MRSA at the same institution. Currently, The Joint Commission and several states are requiring that antibiotic stewardship be conducted by all healthcare institutions.


However, this approach is ill defined at this time and institutions with few resources, such as infectious disease pharmacists and/or infectious disease physicians, are less likely to implement this intervention than institutions that are considered resource rich. Nurses prompting physicians to be aware of negative culture results or responding to sensitivities can reduce inappropriate antibiotic or broad-spectrum antibiotic use, thus helping to reduce MRSA and other HAIs.


This way to best practices

MRSA is still a very important and dangerous hospital pathogen. The best practice for reducing MRSA is to take approaches that will reduce other healthcare-associated pathogens, not solely focusing on MRSA-specific interventions.




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