MRSA Health Article

Definition

Methicillin-resistant Staphylococcus aureus (MRSA) is an infection caused by a strain of Staphylococcus aureus (S. aureus) bacteria that is highly resistant to antibiotics.

Alternative Names

Methicillin-resistant Staphylococcus aureus; Community-acquired MRSA (CA-MRSA); Hospital-acquired MRSA (HA-MRSA)

Causes, incidence, and risk factors

S. aureus (“staph”) is a common bacteria that normally lives on the skin and sometimes in the nasal passages. MRSA refers to S. aureus strains that do not respond to the antibiotics normally used to cure staph infections.

The bacteria can cause infection when it enters the body through a cut, sore, catheter, or breathing tube. The infection can be minor and local (for example, a pimple), or more serious (involving the heart or bone).

Serious staph infections are more common in people with weak immune systems, usually patients in hospitals and long-term care facilities and those receiving kidney dialysis.

MRSA infections are grouped into two types:

Healthcare-associated MRSA (HA-MRSA) infections occur in people who are or have recently been in the hospital. Those who have been hospitalized or had surgery within the past year are at an increased risk. MRSA bacteria are responsible for a large percentage of hospital-acquired staph infections.

Community-associated MRSA (CA-MRSA) infections are ones that occur in otherwise healthy people who have not recently been in the hospital. The infections have occurred among athletes who share equipment or personal items (such as towels or razors) and children in daycare facilities. Members of the military and those who receive tattoos are also at risk. The number of CA-MRSA cases is increasing.

Symptoms

Staph skin infections normally cause a red, swollen, and painful area on the skin. Other symptoms may include:

• Skin abscess
• Drainage of pus or other fluids from the site
• Fever
• Warmth around the infected area

Symptoms of a more serious staph infection may include:

• Rash
• Shortness of breath
• Fever
• Chills
• Chest pain
• Fatigue
• Muscle aches
• Malaise (general feeling of illness)
• Headache