Characteristics of MRSA

MRSA, or methicillin-resistant Staphylococcus aureus bacteria, can cause infections that range from mild to very serious life threatening ones. Most cases of MRSA occur in hospitals or other health care situations, known as health-care associated MRSA, or HA-MRSA. However, another form of this infection has emerged outside health care facilities, known as community-associated MRSA, or CA-MRSA. MRSA differs from the average staph infection in that it is resistant to the broad spectrum antibiotics that are usually used to treat it, making serious complications more likely.

Staphylococcus Aureus, or Staph

• Staphylococcus aureus, or staph, is a common bacteria, found on the skin of approximately 20 percent of healthy people. It is one of the most frequent causes of skin infections. While most infections caused by staph are minor, it can also cause serious infections, such as surgical wound infections and pneumonia. These more serious and often life threatening forms of staph infection are treated with antibiotics. However, several strains of staph, such as MRSA, have developed a resistance to this treatment, becoming immune to the effects of several antibiotics used to treat staph infections.

Characteristics of MRSA Infection

• The most common form of MRSA is skin infections, such as cellulitis, which is an infection of the skin or the fatty tissues immediately beneath it, often emerging as small red bumps. MRSA bacteria can also cause skin infections that present as boils, abscesses, or a sty in the eye area. More serious skin infections, such as impetigo, which causes pus-filled blisters, or carbuncles, which are large pustules under the skin, can also be caused by MRSA. On occasion, MRSA bacteria from skin infections can migrate to other parts of the body, causing more-severe symptoms that can include shortness of breath, fever, joint pain, severe headaches, rash, and low blood pressure. MRSA infections are most common in health-care settings, appearing around surgical wounds or devices such as feeding tubes or catheters. Approximately 60 percent of staph infections in United States hospitals are caused by MRSA.

How MRSA is Spread

• MRSA is often spread by skin to skin contact or by contact with contaminated personal items, such as towels or clothing. MRSA bacteria can contaminate surfaces and be spread to those that touch them. HA-MRSA can be transmitted by contaminated medical supplies and equipment or be carried from one patient to another on the hands of health-care workers. CA-MRSA is most commonly contracted in areas where there is a high concentration of people, such as schools, day care facilities, prisons and dormitories.

Avoiding MRSA Infections

• The most important factor in avoiding the spread of MRSA is thorough and frequent hand washing, especially when exposed to crowded public facilities or health institutions. Since MRSA is most easily transmitted through broken skin, wounds should be covered to prevent infection. Handling of another person's wound or bandages should be avoided, as should sharing towels, bedding, clothing or other personal items. If someone in the household has an open wound, wash laundry in hot, soapy water, and, if possible, use chlorine bleach. Surfaces should be disinfected to prevent the spread of MRSA, as should toys and equipment shared in schools and daycare centers.

Diagnosis and Treatment of MRSA

• An MRSA infection can be difficult to differentiate from an ordinary staph infection, since the symptoms can be very similar. It is very important to test for MRSA in cases of possible staph infection, as treatment that could resolve ordinary staph infections can actually worsen cases of MRSA. Diagnosis is made by taking a skin sample or a sample of pus from a wound and sending it to be cultured for MRSA bacteria, which takes approximately 48 hours. Newer tests are becoming available that can detect MRSA much more quickly, often in a matter of a few hours. Treatments for MRSA infections range from draining of minor infections to treatment with nonpenicillin antibiotics, many of which are effective against MRSA.