By Sue Barnes, RN, CIC
Healthcare-associated infections (HAIs) affect more than 2 million patients annually and cost over $4.5 billion.1 Infection prevention bundles are increasingly being used that include nasal decolonization, and evidence supporting its effectiveness is growing.2 Although mupirocin (trade names including Bactroban, Centany) is commonly used for nasal decolonization, it may be prudent to consider new nasal antiseptics with which antimicrobial resistance is not an issue [trade names including Nozin (alcohol) and 3M and Clorox (iodine).
The rapid action and convenience of these alternatives to antibiotic use may also provide a wider range of opportunities to reduce the infection risk that nasal carriage brings to the healthcare environment.
The role of nasal bacteria in HAI development and transmission and the efficacy of nasal decolonization to reduce infection has been established.3 Mupirocin is the agent used most frequently for nasal decolonization, and the most widely studied.4 However, strains of Staphylococcus aureus resistant to mupirocin continue to increase.5 Thus, in the face of widespread antimicrobial resistance, judicious use of antibiotics has never been more important. Other concerns with mupirocin include that it is slow to reach full effect, generally requiring a five-day, twice-daily application. Patient compliance with this self-application protocol is a common challenge. Furthermore, despite correct application and full course of treatment, eradication of MRSA (methicillin resistant Staphylococcus aureus) and MSSA (methicillin sensitive Staphylococcus aureus) is not complete.6 And finally, although not commonly considered, an FDA warning on the Bactroban product insert indicates that as with any antibiotic, there is a risk of developing Clostridium difficile infection (CDI).7 The newer nasal decolonizing antiseptics are not associated with these risks and concerns.8-9 These antiseptic products permit just-in-time application by healthcare providers rather than patients, fast broad spectrum effect, and little or no resistance potential.
In recent years, incorporation of nasal decolonization into strategies for prevention and control of HAIs has expanded to include the following:
- Controlling outbreaks
- Device-associated infection prevention including catheter related bloodstream infection (CRBSI), catheter associated urinary tract infection (CAUTI) and ventilator associated pneumonia (VAP)
- High-risk patient population infection prevention including ICU (intensive care units), transplant, dialysis, oncology, burn units
- Reducing contact precautions/isolation
- Reduction of MDROs in the community
- Surgical site infection (SSI) prevention
Nasal decolonization has been demonstrated to be one of a number of effective HAI prevention and control measures. The applications for nasal decolonization in healthcare will be described and the evidence supporting each will be graded using the following method borrowed from the Society for Healthcare Epidemiology of America (SHEA) Compendium.10-11
Controlling Outbreaks: Outbreaks of MRSA have been successfully controlled in a variety of healthcare settings including emergency rooms, intensive care units (ICUs), dialysis centers and surgical services. Typically, there are a number of interventions applied, one being nasal decolonization of patients and or healthcare workers, with or without screening tests. Mupirocin is the nasal decolonizing agent studied most to date, and is Food and Drug Administration (FDA)-approved to eradicate MRSA nasal colonization in both patients and healthcare workers.12 However, depending on the study, the degree to which mupirocin has been shown effective in eliminating target organisms is in the range of 50 percent to 78 percent, nowhere near “eradication.”13-14 Despite this limitation, mupirocin has been effective as one of a bundle of interventions to control outbreaks.15 Mupirocin nasal decolonization = High; Antiseptic nasal decolonization = no data.
Device-Associated HAI Prevention: Patients can contaminate their environment with their own bacterial flora which reside on skin and in the anterior nares. This is especially a concern when patients have indwelling devices which can serve as direct conduits into vascular, urinary and respiratory systems, where bacteria can cause CRBSI, CAUTI and/or VAP, resulting in significant patient suffering, morbidity, mortality risk and cost. With most studies in which nasal decolonization was reported to be successful in reducing HAI, it was paired with decolonization of skin.16 Given the growing incidence of antibiotic resistance, there has been a recent surge in study of antiseptics for nasal decolonization. A number of antiseptics and non-chemical technologies have been studied, though more and larger trials are still needed.
Universal versus screening and targeted decolonization is proposed by some studies in order to reduce environmental contamination with pathogens including vancomycin-resistant Enterococcus (VRE).17 Antiseptic agents, as opposed to mupirocin, may be easier and more practical to implement for universal nasal decolonization. Despite limited published studies to date, nasal antiseptics are inexpensive, have a wider spectrum of bacterial efficacy than mupirocin without the resistance, pose little risk to patients, and are designed to be applied by staff vs. patients. These agents include povidone iodine (PVI) and alcohol-based products.18 Most of the decolonization studies to date have focused on eliminating Staphylococcus aureus and MRSA, though other pathogens of concern in healthcare today include multidrug-resistant Gram-negative organisms. Studies in this application category would be rated as follows: Mupirocin nasal decolonization = Moderate; Antiseptic nasal decolonization = Moderate.
High-Risk Patient Populations: Patients considered at high risk for HAIs are those with co-morbidities and/or immunosuppression including those in ICU, burn patients, oncology patients, transplant patients and those on peritoneal dialysis or hemodialysis. In these groups, skin and nasal decolonization have mostly been studied as paired interventions. Visitors, patients and healthcare workers can self-inoculate with pathogens present in the environment and subsequently be implicated in infection transmission to patients. Infections in these high-risk groups are associated with significant morbidity, patient and family suffering and costs. One NICU MRSA infection could cost as much as $27,540.19 Studies of nasal and skin decolonization in burn patients conclude that decolonization reduces Staphylococcus aureus and MRSA infection risk.20 Studies of nasal and skin decolonization in dialysis patients conclude that decolonization reduces infection risk, though repeated treatment is required.21 Evidence ratings for this category: Mupirocin nasal decolonization = Moderate, Antiseptic nasal decolonization = no data.
Reducing Contact Precautions/Isolation: Contact precautions/isolation is utilized to reduce the likelihood that the healthcare worker will transmit pathogens to other patients in the facility; however, contact isolation is costly and can impact safety and satisfaction by reducing the amount of time healthcare workers spend with patients. Additionally, approximately 80 percent of Staphylococcus aureus HAIs have been reported to be associated with self-inoculation by the patient.4 In concordance with these facts, there is growing evidence that the benefits of selective reduction of contact precaution/isolation use can be achieved without risk of increased MRSA transmission or infection by using universal skin decolonization bundled with antibiotic22 or antiseptic23 nasal decolonization. There is strong evidence that MRSA “colonization pressure” (the proportion of MRSA carriers in a facility) is a key driver of transmission rates. This would suggest universal decolonization vs. screening plus targeted decolonization might be prudent in facilities with high MRSA colonization pressure.17
Pathogens other than Staphylococcus aureus/MRSA have not been studied relative to nasal decolonization, possibly because mupirocin has limited antimicrobial activity. Since nasal antiseptics have broader spectrum efficacy they may be effective in reducing isolation and transmission of organisms other than MRSA.18 Pathogenic organisms in addition to Staph aureus and MRSA, although typically not found to colonize nasal mucosa, can transiently colonize the nose. This can lead to patient self-inoculation and/or transmission from patient to patient or healthcare worker to patient.4 Evidence ratings for this category: Mupirocin nasal decolonization = Moderate, Antiseptic nasal decolonization = no data.
Reducing MDROs in the Community: An interesting consequence of patient decolonization in hospital ICUs has been described by one study using a computational model as a “spillover effect,” resulting in a county-wide reduction in MRSA prevalence. This effect was noted within the county studied, not only in patients outside of hospitals, but also in patients in long term care facilities, in nursing homes and inside of hospitals in non-ICU nursing units as well, even at one year.24 Mupirocin nasal decolonization = Low, Antiseptic nasal decolonization patients = no data.
SSI Prevention: Until relatively recently, mupirocin was the only decolonizing agent for SSI prevention studied. This antibiotic ointment is commonly prescribed for application by the patient to the anterior nares for five days pre-operatively. Although neither patient compliance nor elimination of bacteria is reported to be 100 percent with mupirocin, it has been used successfully to reduce the rate of SSI especially in high-risk procedures including orthopedic and cardiac.25 More recently, PVI and alcohol-based nasal antiseptics have been introduced as alternatives to mupirocin due to concerns with mupirocin resistance, transference to of resistance, limited bacterial coverage, patient compliance and provider and patient and satisfaction.6-7