How do you know if you have MRSA?

Staphylococcus aureus (SA) bacteria are common, and around a third of people are colonized by SA (meaning they carry the bacteria in their nose or on their skin without developing an infection). The majority of people colonized with SA do not have any symptoms and aren't aware that they're a carrier.

However, if SA bacteria are able to enter the body they can cause infection. Symptoms will depend on the type of infection they cause.

The MRSA strain of SA can cause a range of infections, including:

• boils and abscesses,
• impetigo (an infectious skin disease),
• cellulitis (an infection of the skin and the fat and tissues that lie immediately beneath it),
• septic wounds,
• chest or urinary tract infection,
• lung infection (pneumonia),
• septicemia ( blood poisoning),
• septic shock (widespread infection of the blood that leads to a fall in blood pressure and organ failure),
• infection of the heart lining (endocarditis),
• severe joint problems (septic arthritis),
• bone marrow infection (osteomyelitis),
• internal abscesses anywhere within the body,
• inflammation of the tissues that surround the brain and spinal cord (meningitis), and
• toxic shock syndrome(a rare, serious bacterial infection).

These infections might be caused by something other than MRSA, so laboratory testing is the only sure way to tell if you have MRSA. Swabs from your skin and nose, or samples of urine, blood or tissue from the infected area will be tested in the hospital laboratory. If you have MRSA, these tests will determine which strain of the bacteria you have, and which antibiotics will be used to treat you.

Many hospitals now test everyone who is being admitted to see if they are colonized with MRSA. Swabs from the skin and nose, urine and blood samples may be tested for the bacteria. If you are colonized with MRSA you will still be admitted, but doctors may give you treatment to reduce or remove the MRSA bacteria.