Methicillin-resistant Staphylococcus aureus (MRSA)

Page originally published 01/05/2024. Page last updated 03/04/2026.

A microscopic image of MRSA.

Staphylococcus aureus (staph) is a very common germ found on the skin or in the nose. Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph that can be resistant to several types of antibiotics. These antibiotics include those related to penicillin, including methicillin, oxacillin, penicillin and amoxicillin.

Anyone can carry MRSA or get a MRSA infection. The risk increases for people staying in a hospital or nursing home, skin-to-skin contact with others (such as in contact sports), and exposure to crowded and unhygienic places.

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Prevention

MRSA can survive on some surfaces, like towels, razors and furniture, for hours, days or even weeks. It can spread to people who touch a contaminated surface and can cause infections if it gets into a cut, scrape or open wound. Even when a surface appears clean, it can still have germs.

Ways to prevent MRSA:

An icon of a hand below a faucet and water droplets.
  • Maintain Good Hygiene
    • Clean hands often and clean your body regularly, especially after exercise.
    • Avoid sharing personal items such as towels, washcloths and razors.
An icon of a bandaid.
  •   Keep Wounds Clean
    • Keep cuts and scrapes clean and covered with bandages or dressing until healed.
      • Follow your healthcare provider's instructions about proper care of the wound. Pus from infected wounds can contain MRSA.
    • Do not pick at or pop the sore.
    • Throw away bandages and tape with the regular trash.
    • Use barriers, like a towel or clothing, between your skin and shared surfaces.
An icon of a spray bottle.
  • Keep Surfaces Clean
    • This includes:
      • Frequently used items such as computer keyboards or handheld electronic devices.
      • Surfaces that contact people's bare skin like desks, chairs, benches, gym equipment, lockers, faucets, light switches, and remote controls.
      • Any surfaces that could contact open wounds, cuts or boils.
    •  Be sure to read disinfectant labels.
    • Use disinfectants that work against MRSA.

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Transmission (Spread)

MRSA spreads in the community through contact with infected people, wounds, or things that have touched infected skin and are carrying the bacteria. Some people who carry MRSA can go on to get a MRSA infection

Most MRSA infections, however, happen in hospital or long-term care facilities. This has become known as healthcare-associated MRSA, or HA-MRSA. Hospital patients, long term care facility residents, those on dialysis, and sick and elderly people are at risk for HA-MRSA.

Community-associated MRSA or CA-MRSA occurs when pus or drainage from MRSA wounds are infectious. Contact with a wound, dirty bandage, or a surface that is contaminated by wound drainage can lead to infection. CA-MRSA causes boils, abscesses (pus-filled infections), and other soft tissue infections not linked to antibiotic use or hospitalization.

Some people are more likely to get CA-MRSA because they may get cuts on their skin or be very close to someone who is infected. This includes athletes, staff and residents of group living facilities, children in daycare, military recruits, first responders, and others. 

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Symptoms

The symptoms of an S. aureus infection, including MRSA, depend on the part of the body that is infected. Broken skin, such as scrapes or cuts, is often the site of a MRSA infection. Most S. aureus skin infections, including MRSA, appear as a bump or infected area on the skin that might be:

  • Red
  • Swollen
  • Painful
  • Warm to the touch
  • Full of pus or other drainage
  • Accompanied by a fever

If you or someone in your family experiences the signs and symptoms of MRSA infection:

  • Contact your healthcare provider, especially if the symptoms include a fever or do not improve within 48 hours.
  •  Do not pick at or pop the bump or sore.
  •  Cover the area with clean, dry bandages until you can see a healthcare provider.  
  • Clean your hands often.

A healthcare provider must send a clinical specimen to a laboratory to determine if MRSA is the cause of an infection.

MRSA infections can cause complications or serious problems in and outside of healthcare settings, including:

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Treatment

If MRSA is confirmed, your healthcare provider will determine which treatments are best for you.

  • Antibiotics
    • Healthcare providers often prescribe antibiotics to treat MRSA infections. While MRSA can be resistant to several antibiotics, meaning these drugs cannot cure the infections, there are antibiotics available to treat MRSA infections.
  • Surgery
    •  Some types of S. aureus  infections need surgery to drain infected areas.

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Resources

County of San Diego

California Department of Public Health (CDPH)

Centers for Disease Control and Prevention (CDC)

For Healthcare Professionals

For Other Groups

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Call the Epidemiology Unit at (619) 692-8499, or send an e-mail, for more information.