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MRSA Tests

What are MRSA tests?

MRSA stands for methicillin-resistant Staphylococcus aureus. It is a type of staph bacteria. Many people have staph bacteria living on their skin or in their noses. These bacteria usually don't cause any harm. But when staph enters the body through a cut, scrape, or other open wound, it can cause a skin infection. Most staph skin infections are minor and heal on their own or after treatment with antibiotics.

MRSA bacteria are different than other staph bacteria. In a normal staph infection, antibiotics will kill the disease-causing bacteria and prevent them from growing. In a MRSA infection, the antibiotics usually used to treat staph infections don't work. The bacteria are not killed and continue to grow. When common antibiotics don't work on bacterial infections, it's known as antibiotic resistance. Antibiotic resistance makes it very difficult to treat certain bacterial infections. Every year, nearly 3 million people in the United States are infected with antibiotic-resistant bacteria, and more than 35,000 people die from the infections.

In the past, MRSA infections mostly happened to hospital patients. Now, MRSA is becoming more common in healthy people. The infection can be spread from person to person or through contact with objects that are contaminated with the bacteria. It is not spread through the air like a cold or flu virus. But you can get a MRSA infection if you share personal items such as a towel or a razor. You may also get the infection if you have close, personal contact with someone who has an infected wound. This can happen when large groups of people are close together, such as in a college dorm, locker room, or military barracks.

A MRSA test looks for the MRSA bacteria in a sample from a wound, nostril, or other body fluid. MRSA can be treated with special, powerful antibiotics. If left untreated, a MRSA infection can lead to serious illness or death.

Other names: MRSA screening, methicillin-resistant Staphylococcus aureus screening

What are they used for?

This test is most often used to find out if you have a MRSA infection. The test may also be used to see if treatment for a MRSA infection is working.

Why do I need a MRSA test?

You may need this test if you have symptoms of a MRSA infection. Symptoms depend on where the infection is located. Most MRSA infections are in the skin, but the bacteria can spread to the bloodstream, lungs, and other organs.

A MRSA infection on the skin may look like a type of rash. A MRSA rash looks like red, swollen bumps on the skin. Some people may mistake a MRSA rash for a spider bite. The infected area may also be:

  • Warm to the touch
  • Painful

Symptoms of a MRSA infection in the bloodstream or other parts of the body include:

What happens during a MRSA test?

A health care provider will take a fluid sample from your wound, nose, blood, or urine. Steps may include the following:

Wound sample:

  • A provider will use a special swab to collect a sample from the site of your wound.

Nasal swab:

  • A provider will put a special swab inside each nostril and twirl it around to collect the sample.

Blood test:

  • A provider will take a sample of blood from a vein in your arm.

Urine test:

  • You will provide a sterile sample of urine in a cup, as instructed by your health care provider.

After your test, your sample will be sent to a lab for testing. Most tests take 24-48 hours to get results. That's because it takes time to grow enough bacteria to be detected. But a new test, called the cobas vivoDx MRSA test, can deliver results much faster. The test, which is done on nasal swabs, can find MRSA bacteria in as little as five hours.

Talk to your health care provider to see if this new test would be a good choice for you.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a MRSA test.

Are there any risks to the test?

There is very little risk to having a wound sample, swab, or urine test.

You may feel a little pain when a sample is taken from a wound. A nasal swab may be slightly uncomfortable. These effects are usually mild and temporary.

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

If your results are positive, it means you have a MRSA infection. Treatment will depend on how serious the infection is. For mild skin infections, your provider may clean, drain, and cover the wound. You may also get an antibiotic to put on the wound or take by mouth. Certain antibiotics still work for some MRSA infections.

For more serious cases, you may need to go to the hospital and get treated with powerful antibiotics through an IV (intravenous line).

Learn more about laboratory tests, references ranges, and understanding results.

Is there anything else I need to know about MRSA tests?

The following steps can reduce your risk of getting a MRSA infection:

  • Wash your hands often and thoroughly, using soap and water.
  • Keep cuts and scrapes clean and covered until they are fully healed.
  • Don't share personal items such as towels and razors.

You can also take steps to reduce antibiotic-resistant infections. Antibiotic resistance happens when people don't use antibiotics in the right way. To prevent antibiotic resistance:

  • Take antibiotics as prescribed, making sure to finish the medicine even after you feel better.
  • Don't use antibiotics if you don't have a bacterial infection. Antibiotics don't work on viral infections.
  • Don't use antibiotics prescribed for someone else.
  • Don't use old or leftover antibiotics.

References

  1. Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; About Antibiotic Resistance; [cited 2020 Jan 25]; [about 3 screens]. Available from: https://www.cdc.gov/drugresistance/about.html
  2. Centers for Disease Control and Prevention [Internet]. Atlanta: U.S. Department of Health and Human Services; Methicillin-resistant Staphylococcus aureus (MRSA): General Information; [cited 2020 Jan 25]; [about 3 screens]. Available from: https://www.cdc.gov/mrsa/community/index.html
  3. Cleveland Clinic [Internet]. Cleveland (OH): Cleveland Clinic; c2020. Methicillin-Resistant Staphylococcus Aureus (MRSA): Overview; [cited 2020 Jan 25]; [about 3 screens]. Available from: https://my.clevelandclinic.org/health/diseases/11633-methicillin-resistant-staphylococcus-aureus-mrsa
  4. Familydoctor.org [Internet]. Leawood (KS): American Academy of Family Physicians; c2020. Methicillin-resistant Staphylococcus aureus (MRSA); [updated 2018 Mar 14; cited 2020 Jan 25]; [about 3 screens]. Available from: https://familydoctor.org/condition/methicillin-resistant-staphylococcus-aureus-mrsa
  5. FDA: U.S. Food and Drug Administration [Internet]. Silver Spring (MD): U.S. Department of Health and Human Services; FDA authorizes marketing of diagnostic test that uses novel technology to detect MRSA bacteria; 2019 Dec 5 [cited 2020 Jan 25]; [about 5 screens]. Available from: https://www.fda.gov/news-events/press-announcements/fda-authorizes-marketing-diagnostic-test-uses-novel-technology-detect-mrsa-bacteria
  6. Kids Health from Nemours [Internet]. Jacksonville (FL): The Nemours Foundation; c1995–2020. MRSA; [cited 2020 Jan 25]; [about 3 screens]. Available from: https://kidshealth.org/en/parents/mrsa.html
  7. Lab Tests Online [Internet]. Washington D.C.: American Association for Clinical Chemistry; c2001–2020. MRSA screening; [updated 2019 Dec 6; cited 2020 Jan 25]; [about 2 screens]. Available from: https://labtestsonline.org/tests/mrsa-screening
  8. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2020. MRSA infection: Diagnosis and treatment; 2018 Oct 18 [cited 2020 Jan 25]; [about 4 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/mrsa/diagnosis-treatment/drc-20375340
  9. Mayo Clinic [Internet]. Mayo Foundation for Medical Education and Research; c1998–2020. MRSA infection: Symptoms and causes; 2018 Oct 18 [cited 2020 Jan 25]; [about 3 screens]. Available from: https://www.mayoclinic.org/diseases-conditions/mrsa/symptoms-causes/syc-20375336
  10. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Blood Tests; [cited 2020 Jan 25]; [about 3 screens]. Available from: https://www.nhlbi.nih.gov/health-topics/blood-tests
  11. National Institute of Allergy and Infectious Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Diagnosis, Methicillin-Resistant Staphylococcus aureus; [cited 2020 Jan 25]; [about 4 screens]. Available from: https://www.niaid.nih.gov/research/mrsa-diagnosis
  12. National Institute of Allergy and Infectious Diseases [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Transmission, Methicillin-Resistant Staphylococcus aureus; [cited 2020 Jan 25]; [about 4 screens]. Available from: https://www.niaid.nih.gov/research/mrsa-transmission
  13. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2020. Methicillin-resistant Staphylococcus aureus (MRSA): Overview; [updated 2020 Jan 25; cited 2020 Jan 25]; [about 2 screens]. Available from: https://ufhealth.org/methicillin-resistant-staphylococcus-aureus-mrsa
  14. UF Health: University of Florida Health [Internet]. Gainesville (FL): University of Florida Health; c2020. Urine culture: Overview; [updated 2020 Jan 25; cited 2020 Jan 25]; [about 2 screens]. Available from: https://ufhealth.org/urine-culture
  15. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2020. Health Encyclopedia: MRSA Culture; [cited 2020 Jan 25]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=mrsa_culture
  16. University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2020. Health Encyclopedia: Rapid Influenza Antigen (Nasal or Throat Swab); [cited 2020 Feb 13]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=mrsa_culture
  17. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Methicillin-Resistant Staphylococcus Aureus (MRSA): Overview; [updated 2019 Jun 9; cited 2020 Jan 25]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/special/methicillin-resistant-staphylococcus-aureus-mrsa/tp23379spec.html
  18. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2020. Health Information: Skin and Wound Culture: How It Feels; [updated 2019 Jun 9; cited 2020 Feb 13]; [about 6 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/wound-and-skin-cultures/hw5656.html#hw5677
  19. World Health Organization [Internet]. Geneva (SUI): World Health Organization; c2020. Antibiotic resistance; 2018 Feb 5 [cited 2020 Jan 25]; [about 3 screens]. Available from: https://www.who.int/news-room/fact-sheets/detail/antibiotic-resistance

The medical information provided is for informational purposes only, and is not to be used as a substitute for professional medical advice, diagnosis or treatment. Please contact your health care provider with questions you may have regarding medical conditions or the interpretation of test results.

In the event of a medical emergency, call 911 immediately.