Methicillin-Resistant Staphylococcus Aureus (MRSA)

The Centers for Disease Control and Prevention (CDC) receives numerous inquiries about methicillin-resistant Staphylococcus aureus (MRSA). This pamphlet answers some of the most frequently asked questions.

What is a staph infection? What is MRSA?
"Staph," or staphylococcus, is a type of bacteria that naturally exist in the environment, including on people's skin. If the bacteria enter under the skin through a cut or scrape, the staph bacteria may cause skin infections that look like pimples or boils. Infections caused by staph may be red, swollen, painful, or have pus or other drainage. Most staph infections are minor and can be treated without antibiotics. Some staph infections resist treatment to a class of antibiotics and are known as Methicillin-Resistant Staphylococcus Aureus or MRSA. This makes these infections harder to treat because it is resistant to the antibiotic most commonly used. There are, however, a couple of other antibiotics to which the bacteria are susceptible and can be used to treat the infection.

Who is at risk for MRSA infection?
People who are generally healthy are not at high risk for MRSA infections. If they get a staph infection, they can usually fight it off. Staph infections, including MRSA infections, occur most frequently among people in hospitals and health-care facilities who have weakened immune systems. MRSA infections are becoming more common in the community, but are still rare.

How long can an infected person carry MRSA?
Some people can carry MRSA for days to many months, even after their infection has been treated.

How are MRSA infections diagnosed?
MRSA infections can be diagnosed when a doctor obtains a sample or specimen from the site of infection and submits it to a laboratory. The laboratory places the specimen on a special "culture" plate containing nutrients, incubates the plate in a warmer and then identifies the bacteria. The final step is for the laboratory to conduct tests using various antibiotics to determine if the bacteria are resistant (able to withstand or tolerate) or sensitive (susceptible to killing) to select antibiotics.

What is the treatment for MRSA?
Although MRSA cannot be effectively treated with antibiotics such as methicillin, nafcillin, cephalosporin or penicillin, it can usually be treated with an antibiotic called vancomycin. Recently, however, a few strains of Staphylococcus aureus have even developed some degree of resistance to vancomycin. The vancomycin-resistant strains may be more difficult to treat. Newer antibiotics are being developed to address this problem.

How can the spread of MRSA be controlled?
Careful hand washing is the single most effective way to control the spread of MRSA. Health care workers should wash their hands after contact with each patient. If the patient is known to have an MRSA infection at Roswell Park Cancer Institute the following occurs:

  • A sign indicating Contact Isolation will be placed the door.
  • Health care workers who enter the room and care for you will wear gloves and a gown. If you are coughing and MRSA is isolated in your respiratory tract, additional precautions may include a mask and goggles.
  • It is important for everyone entering and leaving your room to wash or sanitize their hands.
  • Patients must also wash their hands to avoid spreading the bacteria to others.

Community-Associated Methicillin-Resistant Staphylococcus Aureus (CA-MRSA)

What is CA-MRSA?
Community-associated MRSA infections (CA- MRSA) are MRSA infections in healthy people who have not been hospitalized or had a medical procedure (such as dialysis or surgery) within the past year.

Who gets CA-MRSA?
Anyone can get CA-MRSA, however, outbreaks have been seen among athletes, prisoners, military recruits, daycare attendees, injection drug users and other groups of people who live in crowded settings and/or routinely share contaminated items. Poor hygiene practices, such as lack of hand washing, may spread the bacteria easily.

What are the symptoms associated with CA-MRSA infection?
CA-MRSA infections typically begin as skin infections. They first appear as reddened areas on the skin, or can resemble pimples that develop into skin abscesses or boils causing fever, pus, swelling, or pain.

How are CA-MRSA infections treated?
CA-MRSA skin infections can be treated by draining any abscesses or boils and providing localized care. Antibiotics can be given if necessary. When left untreated, CA-MRSA infections can progress to serious complications. Visit your health care provider if you think you might have a MRSA infection.

How do I know if I got MRSA from the community or from a health care setting?
Most MRSA infections are found in people who are or have recently been hospitalized. CA-MRSA is usually diagnosed when the patient has an MRSA infection and has not had surgery, dialysis, nor been admitted to a hospital or other health care facilities in the past year. CA-MRSA can also be diagnosed when a person has a MRSA infection that began too soon after admission to be acquired in the hospital.

How is it transmitted?
CA-MRSA is spread in the same way as an MRSA infection, mainly through person-to- person contact or contact with a contaminated item such as a towel, clothing or athletic equipment. Bacteria that exist normally on the skin cause CA-MRSA and so it is possible to infect a pre-existing cut not protected by a dressing or other bandage.

If I have MRSA or a CA-MRSA skin infection, what can I do to prevent others from getting infected when I go home?
You can prevent spreading MRSA skin infections to others by following these steps:

  • Cover your wound. Keep wounds that are draining or have pus covered with clean, dry bandages until healed. Follow your health care provider's instructions on proper care of the wound. Pus from infected wounds can contain staph, including MRSA, so keeping the infection covered will help prevent the spread to others. Bandages and tape can be discarded with the regular trash.
  • Clean your hands. You, your family, and others in close contact should wash their hands frequently with soap and water or use an alcohol-based hand sanitizer, especially after changing the bandage or touching the infected wound.
  • Do not share personal items. Avoid sharing personal items, such as towels, washcloths, razors, clothing, or uniforms, that may have had contact with the infected wound or bandage. Wash sheets, towels, and clothes that become soiled with water and laundry detergent. Use a dryer to dry clothes completely.
  • Talk to your doctor. Tell any health care providers who treat you that you have or had a staph or MRSA skin infection.

I have MRSA and I’ll be going home soon. What should I do to prevent my family from getting MRSA?
If you are infected or colonized with MRSA, you should take the following precautions to prevent spreading MRSA to your family and others:

  • Follow good hygiene practices, as described above.
  • Tell any nurses or doctors who treat you that you have MRSA.

Can my children get MRSA by being around a person with MRSA?
Healthy people, including children, are at very little risk of getting infected with MRSA.