MRSA Infection: Symptoms, Diagnosis, Treatment, Prevention

MRSA stands for methicillin-resistant Staphylococcus aureus, a type of contagious bacteria that is resistant to several antibiotics. Staphylococcus (staph) is a bacterial group of more than 30 types. A type called Staphylococcus aureus causes most infections. Methicillin is an antibiotic of the penicillin class that was once effective against Staphylococcus. Over time, the bacteria have developed a resistance to methicillin, these resistant bacteria are named methicillin-resistant Staphylococcus aureus.

Most MRSA infections occur in health-care settings, such as hospital and nursing home. The infection usually starts from skin infection but in health-care settings it can develop into severe conditions such as bloodstream infection, pneumonia or surgery site infection. Approximately 5% of patients in U.S. hospitals carry MRSA, some of them develop an MRSA infection.

In where you live and work, MRSA most often causes skin infections. If left untreated, the infection can develop into severe and life-threatening conditions.


Most staph skin infections, including MRSA, appear as a bump or infected area on the skin that might be:

  • red
  • swollen
  • painful
  • warm to touch
  • full of pus or other drainage
  • accompanied by a fever

Sometimes the skin infection can be confused with a spider bite.

The infected area can quickly turn into deep, painful abscesses, some will go deeper into the body and cause infection in bones, lungs, bloodstream and heart valves.


If you have a skin infection that is not healing, doctors will send a tissue sample to the lab. If your doctor suspect lung infection, a sputum culture may be requested. Throat and nasal secretion samples are also commonly used. A culture may take at least 48 hours, some newer tests can detect staph DNA in hours.


Generally MRSA still respond to certain antibiotics, such as glycopeptides (teicoplanin, vancomycin), linezolid and trimethoprim-sulfamethoxazole.

A small number of MRSA infections are also resistant to vancomycin, which is most commonly used to treat serious MRSA, leaving few to no treatment options.


Health care-associated MRSA (HA-MRSA)

MRSA is more likely to happen in a hospital or nursing home because:

  • High density of people in these places
  • Patients can get the infection by skin-to-skin contact of other patients or healthcare workers or by touching the surfaces of objects that other patients have touched
  • Patients may have open wounds
  • Patients may have a catheter or intravenous drip
  • Patients have weakened immune system

The staph bacteria can live up to 21 days on cotton and 51 days on polyester products. Thus, in health-care settings contaminated surfaces and laundry items should be properly disinfected.

Community-associated MRSA

One-third of healthy people carry staph bacteria on the skin or in the nose with no infection, unless the bacteria go into the body through a cut, an abrasion, or a wound. Often the community outbreaks occur in crowded conditions with skin-to-skin contact, and shared equipment or supplies, such as military training camps, child care centers and jails. Homosexual men have a higher risk of developing MRSA infection.

You can take these steps to reduce your risk of MRSA infection:

  • Maintain good hand and body hygiene. Clean hands often, and clean your body regularly, especially after exercise.
  • Keep cuts, scrapes, and wounds clean and covered until healed.
  • Avoid sharing personal items such as towels and razors.
  • Get care early if you think you might have an infection.

People who inject drugs are more likely to develop deadly MRSA infections than others. Nearly 1 in 10 serious staph infections in 2016 occurred in people who inject drugs such as opioids.

CDC suggests safer injection practices if you are unable or don’t feel ready yet to stop injecting drugs:

  • Use a new needle and equipment every time. Don’t re-use injection equipment, even your own.
  • Use alcohol or soap to clean your hands and the area where you will inject.
  • Do not share any equipment.
  • Set up a clean surface before placing down your injection equipment.

If you’re having an MRSA infection, by following these steps you can prevent the spread.

  • Cover your wounds with clean, dry bandages until healed.
  • Do not pick at or pop the sore.
  • Throw away bandages and tape with the regular trash.
  • Clean your hands often.
  • Do not share personal items such as towels, washcloths, razors, and clothing, including uniforms. 
  • Wash laundry before use by others and clean your hands after touching dirty clothes.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.