Diseases & Conditions


Methicillin-resistant Staphylococcus Aureus (MRSA)

Diseases & Conditions


What is MRSA?

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium that causes infections in different parts of the body. Treatment of MRSA is challenging as it is resistant to a number of widely used antibiotics. MRSA is usually spread by direct contact with an infected wound or from contaminated hands, usually from a hospital or other health care settings.1


What causes MRSA?

Staphylococcal bacteria are relatively common. About 1 in 3 people carry these bacteria on their skin, usually inside their nose and on the surface of their armpits, groin and buttocks. According to the Centers for Disease Control and Prevention, less than 2% of the population chronically carries MRSA.2 It is usually harmless and not a cause for worry for most healthy people. However, it can cause problems if it is able to enter the body or it infects someone having weak health.  Inappropriate use of antibiotics has contributed to the rise of drug-resistant bacteria such as MRSA.3


How does one get MRSA infection?

Most MRSA infections occur in people who have been in hospitals or other health care settings, such as nursing homes and dialysis centers as they have a weak immune system. This is known as health care-associated MRSA which is typically associated with invasive procedures or devices, such as surgeries, intravenous tubing or artificial joints.

When MRSA infection has occurred in the wider community (among healthy people), it is called community-associated MRSA. It is spread by skin-to-skin contact. At-risk populations include groups such as athletes, child care workers and people who live in crowded conditions.3

Though most MRSA infections are not serious, some can be life-threatening.


What are the symptoms of MRSA?

The symptoms of an MRSA infection will depend on what part of the body is infected:2

  • Skin and soft tissue MRSA infections: If MRSA infects the skin, it can result in a wound infection, boil or abscess. If it infects the deeper layers of skin, it is known as cellulitis. Typical symptoms are redness, swelling, tenderness, pain and a discharge of pus. Some people might experience additional symptoms, such as a fever and a general feeling of being unwell.
  • Invasive MRSA infections: If the MRSA bacteria penetrate deeper inside the body or into the blood, they can cause a more serious, invasive infection. Signs of an invasive infection include a high fever or above, chills, dizziness, muscle aches and pains, swelling and tenderness in the affected body part.


How is MRSA diagnosed?

MRSA is diagnosed by obtaining samples of secretions from skin infections, nasal secretions, urine or blood samples. These samples are then cultured (placed on a dish of nutrients that allow bacterial growth) to confirm the presence of MRSA. Since culture technique takes about 48 hours for the bacteria to grow, newer tests that can detect staph DNA in a matter of hours are now becoming more widely available.4


How is MRSA treated?

If a patient has MRSA infection, treatment will depend on the severity of the case. Treatments may include:5

  • Decolonization: If the patient just carries MRSA on the skin, a decolonization treatment with antibacterial is required. Wearing each day new cloth and changing the bedding on a daily basis is also required with decolonization treatment.
  • Treating skin and soft tissue infections: For these kinds of infections, incision and drainage may be required. These treatments involve piercing the tip of the boil or abscess to remove the pus and allow the infected area to heal.
  • Treating invasive infections involves injecting a combination of different antibiotics for several weeks


How can MRSA be prevented?

Simple measures should be taken to stop the spread of MRSA and avoid infection:6

  • In the hospital, infected people are often placed in isolated rooms and visitors should follow strict hygiene procedures such as wear protective garments and disinfecting their hands
  • Community associated MRSA can be prevented by the following methods:
    • Washing hands on regular basis
    • Keeping wounds covered
    • Avoid sharing personal items
    • Showering after athletic games or practices 
    • Sanitizing bed linens



  1. Boucher, Helen W., and G. Ralph Corey. "Epidemiology of methicillin-resistant Staphylococcus aureus." Clinical infectious diseases 46.Supplement 5 (2008): S344-S349.
  2. MRSA infection - Symptoms (MRSA infection) http://www.nhs.uk/Conditions/MRSA/Pages/Symptoms.aspx (Accessed December 22, 2015)
  3. (Centers for Disease Control and Prevention) http://www.cdc.gov/mrsa/healthcare/index.html#q3 (Accessed December 22, 2015)
  4. MRSA (Staph) Infection (Healthline) http://www.healthline.com/health/mrsa#Diagnosis6 (Accessed December 22, 2015)
  5. MRSA infection - Treatment (MRSA infection) http://www.nhs.uk/Conditions/MRSA/Pages/Treatment.aspx (Accessed December 22, 2015)
  6. MRSA infection (Prevention) http://www.mayoclinic.org/diseases-conditions/mrsa/basics/prevention/con-20024479 (Accessed December 22, 2015)