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

Source: NYSDOH; Last Reviewed: October 2007


What is Staphylococcus aureus?

Staphylococcus aureus (S. aureus) is a bacteria normally found on the skin or in the nose of 20 to 30 percent of healthy individuals. When S. aureus is present without causing symptoms, it is called colonization. If symptoms are present, it is called an infection.


What is MRSA?

Methicillin-resistant Staphylococcus aureus (MRSA) is a strain of S. aureus that is resistant to methicillin, an antibiotic in the same class as penicillin, and is traditionally seen in people who have been recently hospitalized or who have been treated at a health care facility (such as treatment at a dialysis center).


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.


How can the spread of CA-MRSA be controlled?

Careful hand washing is the single most effective way to control the spread of CA-MRSA. Skin infections caused by MRSA should be covered until healed, especially to avoid spreading the infection to others. Family members and others with close contact should wash their hands frequently with soap and water. Personal items that may be contaminated (towels, razors, clothing, etc.) should not be shared.

Both the Centers for Disease Control and Prevention (CDC) and the National Collegiate Athletic Association (NCAA) have issued recommendations for preventing the spread of MRSA among athletes. These include practicing good personal hygiene, including showering after practices and competitions and not sharing personal items such as towels. Athletes who participate in sports where equipment is often collectively used are encouraged to reduce sharing as much as possible and to regularly wipe-down equipment/mats with commercial disinfectants or a 1:100 solution of diluted bleach (one tablespoon bleach in one quart water).


Where can I get further information on CA-MRSA?

On the CDC website (Centers for Disease Control and Prevention):


On the NYSDOH website (New York State Department of Health):


A similar fact sheet on general MRSA infections in health care settings is also available on the NYSDOH website.