Published: 18 Jun 2025

ICD9: 041.12      ICD10: B95.62      ICD11: MG51.00

MRSA (Methicillin-Resistant Staphylococcus aureus) infection is an infection caused by a type of staph bacteria that's become resistant to many of the antibiotics used to treat ordinary staph infections.
Essentially, it's a strain of staph that's developed the ability to withstand certain commonly used antibiotics.

Here's a more detailed breakdown:

Key Aspects of MRSA Infection:

Staphylococcus aureus (Staph): Staph bacteria are common microbes that often live harmlessly on the skin or in the nose of about one-third of the population. Most of the time, they don't cause any problems.

Antibiotic Resistance: MRSA has evolved to become resistant to beta-lactam antibiotics. These include methicillin (hence the name), as well as penicillin, amoxicillin, and cephalosporins. This resistance makes MRSA infections more difficult to treat.

How it Spreads:
Direct Contact: Most commonly spread through direct contact with an infected wound or contaminated object, or from person to person. This includes touching a person with MRSA, sharing towels, razors, or athletic equipment.
Indirect Contact: Can also spread through contact with contaminated surfaces, like doorknobs, gym equipment, or medical equipment.
Healthcare Settings: MRSA is more common in hospitals and other healthcare facilities, where people often have weakened immune systems and are more likely to have wounds or invasive devices (e.g., catheters).

Types of MRSA:
Healthcare-Associated MRSA (HA-MRSA): This type occurs in hospitals and other healthcare settings. It is often associated with more serious infections and can be resistant to more antibiotics. People at risk for HA-MRSA are those who have weakened immune systems, are undergoing surgery, have catheters or other invasive devices, or have been hospitalized recently.
Community-Associated MRSA (CA-MRSA): This type occurs in the community, among otherwise healthy individuals. It often presents as skin infections, such as boils or abscesses. Risk factors for CA-MRSA include close contact with infected individuals, participation in contact sports, sharing personal items, and living in crowded conditions.

Symptoms: The symptoms of MRSA infection vary depending on the location and severity of the infection. Common symptoms include:
Skin Infections: Boils, abscesses, pimples, or other skin sores that are red, swollen, painful, and filled with pus. These infections can quickly become deep and serious.
More Serious Infections: In severe cases, MRSA can cause infections in the bloodstream (bacteremia), lungs (pneumonia), heart (endocarditis), bones (osteomyelitis), or other organs. These infections can be life-threatening. Symptoms will vary based on the organ system involved.

Diagnosis:
Culture: The most common way to diagnose MRSA is to take a sample from the infected site (e.g., wound, nasal swab) and culture it in a lab. The culture will determine if MRSA is present and which antibiotics it is susceptible to.
PCR (Polymerase Chain Reaction): Rapid PCR tests can detect MRSA DNA in a sample, providing quicker results than traditional cultures.

Treatment:
Antibiotics: MRSA infections are treated with specific antibiotics that the bacteria is susceptible to, as determined by lab testing. Common antibiotics used to treat MRSA include vancomycin, daptomycin, linezolid, clindamycin, and others. The choice of antibiotic depends on the severity and location of the infection, as well as the patient's overall health.
Drainage of Abscesses: Skin infections may require drainage of pus-filled abscesses.
Incision and Debridement: In severe cases, surgery to remove infected tissue may be necessary.

Prevention:
Good Hygiene: Frequent handwashing with soap and water or using an alcohol-based hand sanitizer is crucial.
Keep Wounds Covered: Cover cuts and scrapes with clean, dry bandages until they are healed.
Avoid Sharing Personal Items: Do not share towels, razors, clothing, or athletic equipment.
Clean Surfaces: Regularly clean and disinfect frequently touched surfaces, especially in gyms and other public areas.
Shower After Exercise: Shower immediately after participating in sports or using gym equipment.
Judicious Use of Antibiotics: Avoid using antibiotics unless necessary, as overuse can contribute to antibiotic resistance.
Hospital Measures: Hospitals and healthcare facilities implement strict infection control measures, such as hand hygiene protocols, isolation of infected patients, and careful cleaning and disinfection of equipment and surfaces.

In summary, MRSA infection is a potentially serious condition caused by a resistant staph bacteria. Good hygiene, prompt treatment of skin infections, and responsible antibiotic use are important for prevention and management.

Important Note: This information is for general knowledge and should not be considered medical advice. If you suspect you have a MRSA infection, see a doctor immediately for diagnosis and treatment. Early detection and appropriate treatment are essential for preventing serious complications.