After reading this article, the learner will be able to:
1. Identify skin and soft tissue infections involving MRSA.
2. State appropriate treatments for MRSA skin and soft tissue infections based on current treatment guidelines.
3. Educate patients on how MRSA skin and soft tissue infections are spread and how to prevent them.
Methicillin-resistant Staphylococcus aureus (MRSA) is a multi-drug resistant bacterium that can cause a variety of infections. Nearly everyone has heard of MRSA or knows someone who has been infected by it. In hospitals and in the community, the number of MRSA infections continues to increase. The costs associated with this infection now reach $1 billion per year,1 meaning that all providers must treat MRSA according to guidelines set forth by the Centers for Disease Control and Prevention (CDC) and Infectious Disease Society of America (IDSA).
Infections caused by MRSA can occur in the community setting (community-associated or CA-MRSA) or in the healthcare setting (healthcare-associated or HA-MRSA). Within the community, CA-MRSA often causes painful skin and soft tissue infections that may have accompanying abscesses. Within the healthcare setting, HA-MRSA can cause pneumonia or infections to areas of recent trauma and/or surgery. These infections are potentially life-threatening.2
Nearly 1 in 3 people have MRSA colonized in their nasal passages yet experience no signs or symptoms of illness. Another 2 in 100 people are carriers of MRSA, meaning that they carry the bacteria but it does not result in infections.3
The nasal passages are likely the primary reservoir for MRSA bacterium colonization,4 however, the groin, axilla and gastrointestinal tract are also common sites for colonization.5 The 2012 Active Bacterial Surveillance Report by the CDC documented 15,138 MRSA infections for every 100,000 people. This was based on results from seven major metropolitan areas.3 The following year, national incidence was closer to 16,560 per 100,000 people.6
Many skin and soft tissue infections are treated based on the assumption that the etiology is MRSA, but it is not confirmed with a wound culture. Due to the lack of wound cultures and a poor definition of CA-MRSA, it is difficult to determine a true calculation of the number of MRSA infections. This leads to underreporting.
At one point, CA-MRSA was more prevalent in certain populations, such as IV drug users, the homeless, people living in crowded situations, and people with poor hygiene and poor sanitation.7 CA-MRSA infections are becoming more prevalent in otherwise healthy adults, and experts believe this is most likely due to the more virulent makeup of CA-MRSA vs. HA-MRSA.
Infections caused by HA-MRSA are associated with increased morbidity and exert a larger burden on the healthcare system.8 A study published in 2013 found that 650 of 868 patients with hospital-onset infections died.6 Reinfection is also a challenging problem with CA-MRSA. Again, this is thought to be due in part to the colonization of MRSA in the nasal passages of people infected with CA-MRSA.4 However, other sites, such as the groin, axilla and gastrointestinal tract, are now noted to be major sites for colonization as well.5
How MRSA Spreads
Infections caused by MRSA can be spread through activities that result in skin-to-skin contact, such as wrestling or football. They can also be spread through sharing of personal items that have come in contact with infected skin, such as razors or towels. This use of those items can also result in the spread of infections to different areas of the body. Living spaces that are cramped or shared, such as military barracks, prisons, gyms and day care centers, can result in the spread of infections from person to person.
The bacterium that causes MRSA can live up to several weeks or longer on surfaces in homes and in the community. "High-touch" areas, such as shopping cart handles, toilet seats, countertops and bathtubs, are areas of concern for lingering MRSA. Use of bleach-based cleaners with help to kill the bacteria on these surfaces. Good hand and body hygiene with anti-bacterial soap and/or alcohol based hand sanitizers will help protect against MRSA infection.3
The cost of treating MRSA has increased over the past decade. In 2005, the cost of MRSA treatment was estimated at between $3.2 and $4.2 billion annually.9 However, in 2013, Lee et al1 reported the cost to third-party payers at between $478 million and $2.2 billion yearly and the cost to society at $1.4 billion to $13.8 billion.
Review of Literature
A review of literature identified guidelines for the treatment of MRSA infection. The most current were published by IDSA in 2011 and updated in 2014. Most of these guidelines, including the IDSA guidelines, recommend treatments referenced in research performed by Moran et al in 2006.10
Moran cultured nearly 500 patients treated in a San Francisco emergency department to identify what bacterium was growing in their wounds. Once the bacterium was identified, it was tested against multiple antibiotics to determine which antibiotics were most effective against each bacterium. In the cases that tested positive for MRSA, researchers determined that clindamycin, trimethoprim-sulfamethoxazole and tetracycline were the most effective at treating MRSA infections.10
Eight years later, Talan and Singer11 updated these findings. The same antibiotics identified in the Moran study were found to be most effective against MRSA, with the addition of linezolid.11 Guidelines from the CDC and IDSA are outlined and compared in the table.
Multiple other articles recommended similar treatment approaches.2,12-15 A treatment guideline by the Health Plan of Nevada suggests cleaning the wound with Hibiclens and applying an antibacterial silver dressing. For more serious infections that do not respond solely to incision and drainage, they suggested antibacterial coverage and referred to the IDSA recommendations for selecting coverage.16
The most extensive guidelines were developed by the Federal Bureau of Prisons.17 These guidelines recommend starting the treatment process by focusing on the size of the infection or abscess to determine treatment. For example, an infection site of less than 5 cm requires only conservative treatments, such as warm compresses and incision and drainage; antibiotic coverage is not indicated. However, infections or abscesses greater than 5 cm require empirical treatment with antibiotics, as outlined by IDSA.
These guidelines are unique because they target the prison population. They state that monitoring for new infections in both prisoners and employees is important and that even small infections should receive treatment promptly. The guidelines identify the following risk factors: recent admission to the hospital; previous skin or soft tissue infection; indwelling catheters; IV drug use; and/or complaint of a "spider or insect bite."
The Federal Bureau of Prisons document also describes infection prevention measures. Education on how infections can be spread (i.e., sharing personal items), prevention of infection transmission (i.e., hand and body hygiene), and the need to seek treatment for suspected infections is important.
The use of good hand hygiene and universal precautions is important for providers to remember as well. Decolonization of those who are colonized or suspected to be colonized can also be used as a preventive measure. Colonized people should shower using chlorhexdine gluconate 4% for 5 days. Another method is to apply 2% mupirocin to the nasal passage for up to 10 days; however, it does not have strong supporting evidence.17
A National Campaign
The CDC and the Healthcare Infection Control Practices Advisory Committee have identified seven strategies to reduce the burden of hospital-acquired infections with multidrug-resistant organisms as part of the Campaign to Reduce Antimicrobial Resistance in Healthcare Settings.18 These strategies are:
prudent use of antimicrobial agents
surveillance of multidrug-resistant organism (MDROs) through clinical cultures and monitoring and follow-up of culture results
infection control precautions including standard and contact precautions
environmental measures to ensure reduction of contaminates on medical equipment and frequently touched surfaces
decolonization of colonized patients.
The Joint Commission has also established National Patient Safety Goals and a national quality improvement incentive to urge hospitals to follow appropriate guidelines to reduce the burden of MDRO hospital-acquired infections and ensure patient health and safety.19
Given the growing prevalence and costly problem of CA-MRSA infections, nurses and other providers need to be well versed in the prevention and treatment strategies identified in national guidelines.
1. Lee BY, et al. The economic burden of community-associated methcillin-resistant Staphylococcus aureus (CA-MRSA). Clin Microbiol Inf. 2013;19(6):528-536.
2. Liu C, et al. Clinical practice guidelines by the Infectious Disease Society of America for the treatment of methicillin-resistant staphylococcus aureus infections in adults and children. Clin Infect Dis. 2011;52(3):1-38.
3. Centers for Disease Control and Prevention. 2014. Active Bacterial Core Surveillance Report, Emerging Infections Program Network, Methicillin-resistant Staphylococcus Aureus, 2014. http://www.cdc.gov/abcs/reports-findings/survreports/mrsa14.html
4. Miller MB, et al. Prevalence and risk factor analysis for methicillin-resistant Staphylococcus aureus nasal colonization in children attending child care centers. J Clin Microbiol. 2011;49(3):1041-1047.
5. Gordon RJ, Lowy FD. Pathogenesis of methicillin-resistant staphylococcus aureus infection. Clin Infect Dis. 2008;46(Suppl 5):350-359.
6. Dante R, et al. National burden of invasive methiclillin-resistant Staphylococcus aureus infections. JAMA Intern Med. 2013;173(2):1970-1978.
7. Charlebois ED, et al. Population-based community prevalence of methicillin-resistant staphylococcus aureus in the urban poor of San Francisco. Clin Infect Dis. 2002;34(4):425-433.
8. Boucher HW, Corey GR. Epidemiology of methicillin-resistant staphylococcus aureus. Clin Infect Dis. 2008;46(Suppl 5):S344-S349.
9. Goetghebeur M, et al. Methicillin-resistant staphylococcus aureus: A public health issue with economic consequences. Canad J Infect Dis Med Microbiol. 2007;18(1):27-34.
10. Moran GJ, et al. Methicillin-resistant S aureus infections among patients in the emergency department. N Engl J Med. 2006;355(7):666-674.
11. Singer A. Management of skin abscesses in the era of methicillin-resistant Staphlyococcus aureus. N Engl J Med. 2014;370(11):1039-1047.
12. Lambert M. IDSA guidelines on the treatment of MRSA infections in adults and children. Am Fam Physician. 2011; 84(4):455.
13. Bartlett JG. Treating MRSA skin and soft tissue infections-new guidelines. Medscape. 2011. http://www.medscape.com/viewarticle/741303
14. Infection Control Today. Physicians issue new treatment guidelines for skin abscesses caused by MRSA. Infection Control Today. March 12, 2014. http://www.infectioncontroltoday.com/news/2014/03/physicians-issue-new-treatment-guidelines-for-skin-abscesses-caused-by-mrsa.aspx
15. Science Daily. New treatment discovered to cure MRSA infection. Science Daily. Nov. 13, 2013. https://www.sciencedaily.com/releases/2013/11/131113144109.htm
16. Health Plan of Nevada. MRSA treatment guidelines. http://www.readbag.com/healthplanofnevada-documents-provider-files-clinical-guidelines-mrsa-guideline-2005-07
17. Federal Bureau of Prisons. Management of methicillin-resistant staphylococcus aureus (MRSA) infections. http://www.bop.gov/resources/pdfs/mrsa.pdf
18. Centers for Disease Control and Prevention. Management of MDROs in healthcare settings. http://www.cdc.gov/hicpac/mdro/mdro_1.html
19. The Joint Commission. National patient safety goals. https://www.jointcommission.org/hap_2016_npsgs/
Vashti Miller is a nurse practitioner and investigator at Columbus Regional Research Institute in Columbus, Ga.