Staphylococcus aureus (S aureus) is a type of bacterium. Like other kinds of bacteria, S aureus frequently lives on the skin and in the nose without causing health problems. Staphylococcus aureus becomes a problem when it is a source of infection in the skin, lungs, or blood. These bacteria can be spread from one person to another through casual contact or through sharing contaminated objects. Methicillin-resistantStaphylococcus aureus (MRSA) bacteria are resistant to commonly used antibiotics, the medicines used to treat bacterial infections. Because of this, MRSA infections are more difficult to treat than ordinary S aureus infections. MRSA that is acquired in a hospital is called hospital-associated MRSA (HA-MRSA). MRSA infections are now becoming more common in healthy, nonhospitalized persons. These infections can occur among young people with cuts or wounds who have close contact with each other, such as members of sports teams. This type of MRSA is called community-acquired MRSA (CA-MRSA). This Patient Page is based on one originally published in the October 17, 2007, issue of JAMA.
Leading causes of antibiotic resistance include
Bacterial mutation—bacteria that survive treatment with one antibiotic may develop resistance to the effects of that drug and similar medicines.
Unnecessary antibiotic use—for decades, antibiotics have been prescribed for colds, flu, and other viral infections that do not require or respond to antibiotics.
Antibiotics in food—antibiotics are commonly given to cattle, pigs, and chickens.
Risk factors for HA-MRSA include
Current or recent hospitalization
Residence in a long-term care facility
Invasive procedures such as urinary catheters, intra-arterial lines, or central venous lines
Recent or long-term antibiotic use
Family members or close contacts who are health care workers
Chronic renal dialysis
Risk factors for CA-MRSA include
Participation in contact sports
Sharing towels or athletic equipment
Having a weakened immune system, such as in persons with HIV/AIDS
Living in crowded or unsanitary conditions, such as prisons
Both HA-MRSA and CA-MRSA still respond to certain medications. Doctors usually treat suspected and confirmed infections with vancomycin, but resistance to vancomycin can also occur. Few other drugs are available. Current research is directed toward development of new antibiotics.
To prevent the spread of MRSA:
Ask hospital staff to wash their hands before touching you.
Wash your own hands frequently and avoid sharing personal items like razors or towels.
Follow hospitals' isolation procedures for gowns, gloves, and masks.
Wipe down shared equipment at gyms before and after using them.
Athletes should participate in sports only if any open wounds can be kept covered during participation.
Centers for Disease Control and Prevention www.cdc.gov/mrsa
Mayo Clinic Health Information www.mayoclinic.com/health/mrsa/DS00735
American Academy of Pediatrics Healthy Children www.healthychildren.org
To find this and previous JAMA Patient Pages, go to the Patient Page Index on JAMA's Web site at www.jama.com. Many are available in English and Spanish.
Sources: Centers for Disease Control and Prevention, Mayo Clinic
Topic: INFECTIOUS DISEASES
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776.
Zeller JL, Golub RM. MRSA Infections. JAMA. 2011;306(16):1818. doi:10.1001/jama.306.16.1818