Staph Infection: Question and Answer

What is MRSA?

MRSA is a type of Staphylococcus aureus (S. aureus). Staphylococcus aureus, often referred to simply as "staph," are bacteria commonly carried on the skin or in the nose of healthy people. Some S. aureus are resistant to the class of antibiotics that are frequently used to treat staph such as methicillin-and thus are called methicillin-resistant S. aureus(MRSA).

Who gets MRSA?

S. aureus (staph) including MRSA can be spread among people having close contact with infected people. MRSA is almost always spread by direct physical contact and not through the air. Spread may also occur through indirect contact by touching objects (e.g., towels, sheets, wound dressings, clothes, workout areas, or sports equipment) contaminated by the infected skin of a person with staph bacteria or MRSA.

Just as S. aureus can be carried on the skin or in the nose without causing any disease, MRSA can be carried in this way also. This is known as colonization.

MRSA infections are usually mild, superficial infections of the skin that can be treated successfully with proper skin care and antibiotics. MRSA, however, can be difficult to treat and can progress to life-threatening blood or bone infections because there are fewer effective antibiotics available for treatment.

MRSA infections occur commonly among persons in hospitals and healthcare facilities. However, MRSA can cause illness in persons outside of hospitals and healthcare facilities as well. Cases of MRSA infection in the community have been associated with recent antibiotic use, sharing contaminated items, having recurrent skin diseases, and living in crowded settings. Clusters of skin infections caused by MRSA have been described among injecting drug-users; aboriginals in Canada, New Zealand and Australia; Native Americans in the United States; incarcerated persons; players of close-contact sports; men who have sex with men (MSM); and other populations. Most of the transmission in these settings appeared to be from people with active MRSA skin infections.

How do I know if I got MRSA from the community or from a healthcare setting?

Persons with MRSA infections that meet all of the following criteria likely have community-associated MRSA (CA-MRSA) infections:

  • Diagnosis of MRSA was made in the outpatient setting or by a culture positive for MRSA within 48 hours after admission to the hospital.

  • The patient has no medical history of MRSA infection or colonization.

  • The patient has no medical history in the past year of:
  • The patient has no permanent indwelling catheters or medical devices that pass through the skin into the body.

If my doctor or healthcare provider has told me that I have an MRSA skin infection, what can I do to prevent others from getting infected?

You can prevent spreading an MRSA infection to those you live with or others around you by following these steps:

  1. Keep infections, particularly those that continue to produce pus or to drain material, covered with clean, dry bandages. Follow your healthcare provider's instructions on proper care of the wound. Pus from infected wounds can contain MRSA and spread the bacteria to others.

  2. Advise your family and other close contacts to wash their hands frequently with soap and warm water, especially if they change your bandages or touch the infected wound or potentially infectious materials.

  3. Avoid sharing personal items (e.g., towels, washcloth, razor, clothing, or uniforms) that may have had contact with the infected wound and potentially infectious material. Wash linens and clothes that become soiled with hot water and laundry detergent. Drying clothes in a hot dryer, rather than air-drying, also helps kill bacteria in clothes.

  4. Tell any healthcare providers who treat you that you have an antibiotic-resistant staph skin infection.

How is MRSA diagnosed?

A sample of the infected wound (either a small biopsy of skin or pus taken with a swab) must be obtained to grow the bacteria in the microbiology laboratory. Once the staph is growing, the organism is tested to determine which antibiotics will be effective for treating the infection. A culture of skin lesions is especially useful in recurrent or persistent cases of skin infection, in cases of antibiotic failure, and in cases that present with advanced or aggressive infections.

What is the mortality rate of CA-MRSA?

CA-MRSA infections are typically limited to the skin and do not result in severe disease (such as infection of the bloodstream) or death. However, on rare occasion, CA-MRSA can cause severe illness even when treated quickly, as in the cases of four children who died from CA-MRSA (18).

Source: Centers for Disease Control and Prevention (www.cdc.gov).


Last Editorial Review: 8/22/2003