CDC’s Q&A on community MRSA infections

How to prevent spread to others

The Centers for Disease Control and Prevention (CDC) provides the following answers to some of the most frequently asked questions about community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA).

Question: What is MRSA and how is it spread?

Answer: MRSA is a type of Staphylococcus aureus often referred to simply as "staph." These bacteria commonly are carried on the skin or in the noses of healthy people.

Some S. aureus are resistant to the class of antibiotics that frequently are used to treat staph such as methicillin and thus are called methicillin-resistant S. aureus (MRSA). MRSA can be spread among people who have close contact with infected people. MRSA almost always is spread by direct physical contact and not through the air.

Spread also may 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.

Question: Why does the CDC think so many cases of MRSA are being recognized across the country?

Answer: MRSA has been recognized as a problem in the health care setting for more than 20 years. The CDC believes that MRSA has been emerging in the community over the last several years.

It is difficult to determine whether there is an increase in MRSA disease in the community or an increased awareness and recognition of MRSA disease. However, it is clear that some of the recently recognized outbreaks of CA-MRSA are associated with strains that have some unique properties compared to the traditional hospital-based MRSA strains, suggesting some biologic properties (such as virulence factors) may allow the CA-MRSA strains to spread more or cause more disease; however, these hypotheses need testing and confirmation.

Question: How do I know if I got MRSA from the community or from a health care setting?

Answer: People with MRSA infections that meet all of the following criteria likely have 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:

— hospitalization;

— admission to a nursing home, skilled nursing facility, or hospice;

— dialysis;

— surgery.

• The patient has no permanent indwelling catheters or medical devices that pass through the skin into the body.

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

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

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

• 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.

• 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.

• Tell any health care providers who treat you that you have an antibiotic-resistant staph skin infection.

Question: How is MRSA diagnosed?

Answer: 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.