MRSA (Methicillin-Resistant Staphylococcus aureus)

The following information is adapted from the Maine and U.S. Centers for Disease Contro

What is Staphylococcus aureus?

Staphylococcus aureus, often referred to as "staph," are bacteria commonly carried on the skin or in the nose of healthy people. About 25% to 30% of the population carries staph in their nose or on their skin and do not know they are carrying them. They do not have any signs or symptoms of illness. This is called “colonization.” Sometimes staph bacteria can cause infection, especially pimples, boils, and other skin problems. Occasionally, staph can cause very serious illness if they get into the bloodstream, the lungs, or a wound after surgery. 

What is MRSA (methicillin-resistant Staphylococcus aureus)?

MRSA is a type of staph that is resistant to treatment with antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin, and amoxicillin. While 25% to 30% of the population is colonized with staph, approximately 2% is colonized with MRSA.

How is MRSA spread? 

Staph infections, including MRSA are spread by direct skin-to-skin contact with another person. It is also spread through contact with items that have been touched by people with staph. For example, staph can be spread by shaking hands, wrestling, sharing towels, or sharing athletic equipment. Fluid from staph infections such as boils is especially infectious. 

What are the signs and symptoms of MRSA?

Staph bacteria, including MRSA, can cause skin infections that may look like a pimple or boil and can be red, swollen, painful, or have pus or other drainage. They can also cause more serious infections such as pneumonia, bloodstream infections, or surgical wound infections.

How are MRSA infections treated?

Staph skin infections, including MRSA may heal by themselves if kept clean and dry. Sometimes staph skin infections are treated by draining the abscess or boil and may not require treatment with antibiotics. Sometimes staph infections require treatment with antibiotics. If after visiting your healthcare provider the infection is not getting better after a few days, contact them again. If other people you know or live with get the same infection tell them to go to their healthcare provider.

Is it possible for a staph or MRSA skin infection to come back after it is cured?

Yes. It is possible to have a staph or MRSA skin infection come back (recur) after it is cured. To prevent this from happening, follow your healthcare provider’s directions while you have the infection, and follow the prevention steps after the infection is gone.

What should I do if I think I have a MRSA infection?

Keep the area clean and dry. See your healthcare provider, especially if the infection is large, painful, warm to the touch, or does not heal by itself.

How will my healthcare provider know if I have a MRSA infection?

Your healthcare provider will usually take a sample of your skin infection with a swab (like a Q-tip) and send it to the laboratory to see if the infection is caused by staph. If the infection is caused by staph, a second lab test will be done to determine if the staph is MRSA. Blood or other body fluids can also be tested for staph.  

Does MRSA cause more serious infections than other staph?

MRSA does not usually cause more serious infections than other staph. However, because MRSA can’t be identified without special lab tests, it is not always identified and treated correctly when antibiotic treatment is needed.  Doctors may assume that a MRSA infection is a common staph infection and treat with antibiotics that do not kill MRSA. This potential delay in recognizing and treating MRSA infections effectively can result in prolonged illness and rare life-threatening illnesses in the blood, heart, and bones. Some MRSA, just like some staph, may produce substances that cause more severe infections.  

How can I prevent staph or MRSA skin infections?

Practice good hygiene:

  • Keep your hands clean by washing thoroughly with soap and water or using an alcohol-based hand sanitizer.
  • Keep cuts and scrapes clean and covered with a bandage until healed.
  • Avoid contact with other people’s wounds or bandages.
  • Avoid sharing personal items such as towels or razors.

How common are staph and MRSA infections?

Staph bacteria are one of the most common causes of skin infection in the United States and are a common cause of pneumonia, surgical wound infections, and bloodstream infections. The majority of MRSA infections occur among patients in hospitals or other healthcare settings. However, MRSA infections are becoming more common in the community setting or outside of hospitals and healthcare facilities. The term “community-associated” MRSA (CA-MRSA) is used to describe MRSA infections in people who have not been hospitalized or had a medical procedure (such as dialysis, surgery, catheters) within the past year.

Are certain people at increased risk for community-associated MRSA infections?

Clusters of CA-MRSA skin infections have been reported among athletes, military recruits, children, Pacific Islanders, Alaskan Natives, Native Americans, men who have sex with men, and prisoners. Factors that have been associated with the spread of MRSA skin infections include: close skin-to-skin contact, openings in the skin such as cuts or abrasions, contaminated items and surfaces, crowded living conditions, and poor hygiene.

If I have a staph, or MRSA skin infection, what can I do to prevent others from getting infected?

You can prevent spreading staph or 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. Follow your healthcare provider’s instructions on proper care of the wound. Pus from infected wounds can contain staph and MRSA, so keeping the infection covered will help prevent the spread to others. Bandages or tape can be discarded with the regular trash.
  • Clean your hands. You, your family, and others in close contact should wash their hands often with soap and warm water or use an alcohol-based hand sanitizer, especially after changing the bandage or touching the infected wound.
  • Do not share 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. Drying clothes in a hot dryer, rather than air-drying, also helps kill bacteria in clothes.
  • Avoid contact sports and other skin-to-skin contact until your infection has healed.
  • Talk to your doctor. Tell any healthcare providers who treat you that you have or had a staph or MRSA skin infection.

Where can I get more information?

For more information contact your healthcare provider or local health center.  You can also contact the Maine Center for Disease Control and Prevention by calling 1-800-821-5821 or visiting the website  The federal Centers for Disease Control and Prevention website - – is another excellent source of health information.