Methicillin-resistant Staphylococcus aureus (MRSA)

Definition

MRSA stands for methicillin-resistant Staphylococcus aureus. MRSA is a "staph" germ (bacteria) that does not get better with the type of antibiotics that usually cure staph infections.

When this occurs, the germ is said to be resistant to the antibiotic.

Causes

Most staph germs are spread by skin-to-skin contact (touching). A doctor, nurse, other health care provider, or visitors to a hospital may have staph germs on their body that can spread to a patient.

Once the staph germ enters the body, it can spread to bones, joints, the blood, or any organ, such as the lungs, heart, or brain.

Serious staph infections are more common in people with chronic (long-term) medical problems. These include those who:

MRSA infections can also occur in healthy people who have not recently been in the hospital. Most of these MRSA infections are on the skin, or less commonly, in the lung. People who may be at risk are:

Symptoms

It is normal for healthy people to have staph on their skin. Many of us do. Most of the time, it does not cause an infection or any symptoms. This is called "colonization" or "being colonized." Someone who is colonized with MRSA can spread it to other people.

A sign of a staph skin infection is a red, swollen, and painful area on the skin. Pus or other fluids may drain from this area. It may look like a boil. These symptoms are more likely to occur if the skin has been cut or rubbed, because this gives the MRSA germ a way to "get in." Symptoms are also more likely in areas where there is more body hair, because the germ can get into hair follicles.

MRSA infection in people who are in health care facilities tend to be severe. These infections may be in the bloodstream, heart, lungs or other organs, urine, or in the area of a recent surgery. Some symptoms of these severe infections may include:

Exams and Tests

The only way to know for sure if you have a MRSA or staph infection is to see a provider.

A cotton swab is used to collect a sample from an open skin rash or skin sore. Or, a sample of blood, urine, sputum, or pus from an abscess may be collected. The sample is sent to a lab to test for staph and MRSA. If MRSA is found, it will be tested to see which antibiotic should be used to treat the infection.

Treatment

Draining the infection may be the only treatment needed for a skin MRSA infection that has not spread. A provider should do this procedure. DO NOT try to pop open or drain the infection yourself. Keep any sore or wound covered with a clean bandage.

Severe MRSA infections are becoming harder to treat. Your lab test results will tell the doctor which antibiotic will treat your infection. Your doctor will follow guidelines about which antibiotics to use, and will look at your personal health history. MRSA infections are harder to treat if they occur in:

You may need to keep taking antibiotics for a long time, even after you leave the hospital.

Be sure to follow instructions on how to care for your infection at home.

Support Groups

For more information about MRSA, see the Centers for Disease Control website: www.cdc.gov/mrsa.

Outlook (Prognosis)

How well a person does depends on how severe the infection is, and the person's overall health. Pneumonia and bloodstream infections due to MRSA are linked with high death rates.

When to Contact a Medical Professional

Call your provider if you have a wound that seems to get worse instead of healing.

Prevention

Follow these steps to avoid a staph infection and to prevent an infection from spreading:

Simple steps for athletes include:

If you have surgery planned, tell your provider if:


Review Date: 9/27/2017
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Internal review and update 11/06/2018 by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

This information should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. © 1997- 2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.