MRSA Testing

California state law requires hospitals to test some patients for a germ called methicillin-resistant Staphylococcus aureus, or MRSA. If you're admitted to the hospital at UCSF Medical Center for surgery and you're considered susceptible for MRSA infection, you will be tested for this germ.

Staphylococcus aureus, pronounced staff-ill-oh-KOK-us AW-ree-us, or "staph" are a common bacteria. MRSA is a type of staph that isn't killed by penicillin or similar antibiotics, the drugs most commonly used to treat staph infections. It is resistant to many antibiotics, making it more difficult to treat.

About one out of every three people has staph on his or her skin or in the nose without it causing any problem, and about one out of every 100 people carry MRSA without getting sick. However, in some cases staph or MRSA can cause an infection. An infection may look like any of the following:

  • Sores that look and feel like spider bites
  • Red, painful bumps under the skin
  • Swollen, hot pus-filled cut
  • Blisters filled with fluid or red skin with a honey-colored crust, usually on the face
  • Area of red, warm firm skin that's painful and gets larger, usually on the legs

Infections caused by MRSA don't look any different from infections caused by ordinary staph.

What Your Test Results Mean

If your MRSA test is positive, you are considered "colonized" with MRSA. Being colonized simply means that at the moment your nose was swabbed, MRSA was present. If the test is negative, it means you aren't colonized with MRSA.

In most cases, being colonized with MRSA doesn't make you sick and no treatment is necessary. If you have an infection, your doctor will treat it. Treatments may include draining the sores or taking antibiotics.

What to Do if You Test Positive for MRSA

Carry on with your daily life as usual and follow the simple suggestions listed below to help prevent MRSA from causing problems.

In the Hospital

  • Remind your doctors, nurses and other health care providers to clean their hands before touching you or items in the room.
  • Ask visitors to clean their hands when they enter and leave your room.

At Home

  • Clean your hands often — before you eat or prepare food, after using the bathroom and before and after changing your dressing or bandage. People who live with you should clean their hands often as well.
  • Make sure you know how to care for any wounds or intravenous (IV) "lines," such as a catheter or port, if you have them.
  • Keep wounds clean and change bandages as instructed until the wounds have healed.
  • Routinely clean the surfaces you touch frequently, such as faucets, doorknobs, remote controls, keyboards, telephones, chair and couch arms and kitchen surfaces. Use a commercial wipe or soap and water.

Staph and MRSA can spread to others through skin-to-skin contact and by touching surfaces contaminated with the bacteria, such as towels or used bandages. It's generally not spread through the air.

What to Do if You Have an Infection

Routine cleaning of your hands and environment is the best way to prevent your infection from spreading to others.

If you're given antibiotics, take all of them, even if your symptoms improve. If your infection doesn't improve within several days, call your doctor.

Your doctor or nurse can answer any other questions you have about MRSA.


Reviewed by health care specialists at UCSF Medical Center.

This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.

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