At a glance
- MRSA can cause severe problems in healthcare facilities.
- MRSA can be resistant to several antibiotics.
- MRSA prevention efforts can reduce infections.
Overview
CDC considers methicillin-resistant Staphylococcus aureus (MRSA) a "serious threat."1 In healthcare facilities, such as hospitals or nursing homes, MRSA can cause severe problems including:
- Bloodstream infections
- Pneumonia
- Surgical site infections
- Sepsis
- Death
CDC encourages clinicians to consider MRSA in the diagnosis of skin and soft tissue infections (SSTIs) compatible with S. aureus infections, especially those that are purulent (e.g., fluctuant or palpable fluid-filled cavity, yellow or white center, central point or "head," draining pus, or possible to aspirate pus with needle or syringe).
Risk factors
People are at higher risk for MRSA infection when they:
- Have surgery.
- Have medical devices inserted in their body.
- Use needles to inject drugs.
How it spreads
In healthcare settings, MRSA usually spreads through direct contact with an infected wound or from contaminated hands. People who carry MRSA but do not have signs of infection (i.e., people who are colonized) can spread the bacteria to others.
How common it is
Studies show that about one in three people (33%) carry S. aureus bacteria in their nose (the main site of colonization), usually without any illness. About two in every 100 people (2%) carry MRSA, although this may be higher in certain populations. Although many people carry MRSA bacteria in their nose, most do not develop serious MRSA infections.
Skin infections caused by MRSA are common in the general community.
Information about MRSA rates in U.S. hospitals is available through the National Healthcare Safety Network (NHSN).
Clinical features
Most S. aureus skin infections, including MRSA, appear as a bump or infected area on the skin that might be:
- Red.
- Swollen.
- Painful.
- Warm to the touch.
- Full of pus or other drainage.
- Accompanied by a fever.
A patient presenting with a "spider bite" should raise suspicion of an S. aureus infection, including MRSA.
SSTIs, carbuncles and abscesses are the most reported clinical manifestations.
The role of MRSA in cellulitis without abscess or purulent drainage is less clear since cultures are rarely obtained.
Prevention
Numerous studies show that MRSA prevention efforts can reduce infections.
Successful MRSA prevention requires action at the healthcare facility level, among both healthcare providers and leadership. See CDC's strategies to prevent S. aureus in acute care facilities and Society for Healthcare Epidemiology of America (SHEA)/Infectious Diseases Society of America (IDSA)/Association for Professionals in Infection Control and Epidemiology (APIC) Practice Recommendation.
Testing
Providers can test some patients to see if they carry MRSA in their nose or on their skin. This test involves rubbing a cotton-tipped swab in the patient's nostrils or on the skin.
The only way to know if MRSA is the cause of an infection is to test for the bacteria in a laboratory.
Treatment and recovery
Treatment and decolonization
The main treatment for MRSA skin infections is incisions and drainage. Antibiotics may also be required. Providers can also apply topical medicines and antiseptics to decrease the amount of S. aureus on a person's body.
Antibiotics
Culture and susceptibility testing should guide therapy and antibiotic decisions for patients with severe infections that do not respond to initial treatment attempts.
Complications
MRSA skin infections can develop into more serious infections. It is important to discuss a follow-up plan with your patients in case they develop symptoms, or if symptoms do not improve within 48 hours.
Resources and tools
Guidelines
- Outpatient management of SSTIs in the era of community-associated MRSA.
- Clinical Practice Guidelines by the IDSA for the Treatment of MRSA Infections in Adults and Children (2011)
- Infectious Diseases Society of America (IDSA)