Updated information on MRSA infections
Staphylococcus aureus (yellow) is a bacterium found in the skin and mucous membranes.
While the CDC does not routinely recommend decolonization,9 this treatment may be advisable in certain circumstances. For example: (1) patients who are immunocompromised (e.g., those with leukemia, another cancer or HIV) and might develop particularly life-threatening infections; and (2) patients who live in close quarters with others, such as in mental institutions, prisons or military barracks.
Decolonization can be accomplished by washing with chlorhexidine (Hibiclens, Exidine, CIDA-STAT). Hexachlorophene (Phisohex) can also be used, but only in combination with mupirocin (Bactroban), not by itself. Mupirocin ointment placed in the nostrils twice daily for seven days will also result in decolonization.
Mupirocin nasal ointment plus bleach baths (one tablespoon of bleach in one quart of water) will achieve long-term S. aureus decolonization of the skin. Some strains of MRSA are resistant to mupirocin (mupA gene found on USA300 MRSA clones).
New nondrug therapies are also being considered for their potential to combat MRSA. These include lemongrass essential oil, which research has shown to be effective in completely inhibiting all MRSA colony growth.10 Tea tree oil also has been shown to be effective. There is clinical evidence that topical preparations may be more effective than conventional antibiotics in preventing transmission of CA-MRSA.11
Another substance being considered to combat MRSA is French clay. The clay has been found to kill several types of bacteria, and researchers recently discovered that specific minerals in the clay are toxic to MRSA.12
Not all patients with MRSA cellulitis will respond to initial treatment, and clinicians must recognize when patients need more aggressive treatment or hospitalization. Patients who meet at least two of the following criteria may need hospital treatment:
- Fever >100.4°F
- WBC count >13,000/µL
- Bands >10%
- Hand cellulitis
- Facial cellulitis
- Older than age 70 years
- Failing outpatient treatment
Another warning sign is the presence of cellulitis with no drainable pus. This raises concern of group A streptococcal infection. In this instance, clinicians should keep in mind that TMP-SMX and doxycycline, both of which are effective against MRSA, are less effective against group A streptococcus.
Therefore, treatment should also include amoxicillin, ampicillin or penicillin. Use of clindamycin should also be considered in these cases because it may be effective against both MRSA and group A streptococcus. The typical regimen for treating a co-infection should include vancomycin and clindamycin.
When treating patients with MRSA infections, health-care workers should take care to reduce the risk of spreading the organism to others. Standard precautions will help accomplish this goal.
Clinicians must be certain to wash their hands before and after examining patients, and they should wear gloves anytime they might come into contact with blood, body fluids, secretions or contaminated items. The gloves should be removed immediately after use to prevent transfer of microorganisms. Health-care workers who do not remove gloves quickly could contaminate environmental surfaces or spread the organism to other patients.
For example, if a clinician examines a patient and then touches a drawer, chart, or doorknob without removing his or her gloves, those surfaces may become contaminated, and the organism may be spread. MRSA can live on some surfaces for hours or even days.
Clinicians should wash their hands after each examination whether they wore gloves or not.
In addition to gloves, other personal protective equipment should be used to prevent the spread of MRSA. Practitioners should wear masks and eye protection to prevent body fluids and blood from spraying into mucous membranes of the provider's eyes, nose and mouth during procedures or patient-care activities. Clinicians should also wear a disposable gown, both to protect their skin and to prevent their clothing from becoming contaminated during patient care.
Any patient-care equipment that has been soiled with blood, body fluids, secretions or excretions must be handled properly to avoid transferring microorganisms to other patients and environments. The same is true for linens. Additionally, rooms used by patients with MRSA must undergo terminal cleaning.
A new disinfecting tool may be on the horizon, however. Aerosolized hydrogen peroxide has been shown to neutralize MRSA on environmental surfaces.13 Studies have demonstrated that the hydrogen peroxide is nearly 100% effective and that its disinfecting effect lasts for weeks. Aerosolized hydrogen peroxide is also cost-effective, making it a promising new infection-control measure.
In addition to environmental cleaning, clinicians may want to explore other methods for reducing MRSA transmission, including:
- Aggressively screening health-care workers for MRSA colonization
- Performing active-surveillance cultures for MRSA in at-risk patients and putting those who test positive on contact precautions.
Ultimately, managing MRSA requires a comprehensive approach that includes prevention, timely treatment and efforts to reduce transmission. The more informed clinicians are about how to undertake each of these steps, the more likely that the number of CA-MRSA cases will decline in the future.Joe Gilboy, PA-C, is a staff member in the emergency department at Hoag Hospital in Newport Beach, Calif. Gilboy has also served as an educational consultant to the physician assistant programs at Stanford University in Palo Alto, San Joaquin Valley College in Visalia and Loma Linda University in Loma Linda, all in California; and Touro University in Henderson, Nev.
- National Institute of Allergy and Infectious Diseases. Methicillin-resistant Staphylococcus aureus.
- Centers for Disease Control and Prevention. MRSA statistics.
- State of Rhode Island Department of Health. CA-MRSA.
- Centers for Disease Control and Prevention. People at Risk of Acquiring MRSA Infections.
- Sivagnanam S, Deleu D. Red man syndrome. Crit Care. 2003;7:119-120.
- Oral Zyvox shows cost savings for outpatient treatment of skin, other infections vs. vancomycin. Medical News Today. October 8, 2005.
- Suzuki M, Kazuhiro Y, Nagao MI, et al. Antimicrobial ointments and methicillin-resistant Staphylococcus aureus USA300. Emerg Infect Dis. 2011;17:1917-1920.
- Chen AE, Carroll KC, Diener-West M, et al. Randomized controlled trial of cephalexin versus clindamycin for uncomplicated pediatric skin infections. Pediatrics. 2011;127:e573-e580.
- Centers for Disease Control and Prevention. Management of Multidrug Resistant Organisms in Healthcare Settings, 2006.
- Chao S, Young G, Oberg C, Nakaoka K. Inhibition of methicillin-resistant Staphylococcus aureus (MRSA) by essential oils. Flav Frag J. 2008;23:444-449.
- Dryden MS, Dailly S, Crouch M. A randomized, controlled trial of tea tree topical preparations versus a standard topical regimen for the clearance of MRSA colonization. J Hosp Infect. 2004;56:283-286.
- French clay can kill MRSA and "flesh-eating" bacteria. ScienceDaily.Science News. October 25, 2007.
- Dryden M, Parnaby R, Dailly S, et al. Hydrogen peroxide vapour decontamination in the control of a polyclonal meticillin-resistant Staphylococcus aureus outbreak on a surgical ward. J Hosp Infect. 2008;68:190-192.
All electronic documents accessed December 5, 2011 .