Symptoms of MRSA and detection

Staphylococcus aureus (SA) bacteria are common, and about 1 in 3 people are colonised by the bacteria. Most of those who are colonised with SA do not develop an infection and so do not have any symptoms.

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

Most SA infections are skin infections, including:
- boils (pus-filled infections of hair follicles),
- abscesses (collections of pus in pockets under the skin),
- styes (infection of glands in the eyelid),
- carbuncles (infections larger than an abscess, usually with several openings to the skin),
- cellulitis (infection of the skin and the fat and tissues that lie immediately beneath it), and
- impetigo (a skin infection that produces pus-filled blisters).

You should keep an eye on minor skin problems like spots, cuts or burns. If you have a wound that becomes infected you should see your doctor.

Although most SA infections are skin infections, if SA bacteria are able to enter the bloodstream (bacteraemia) they can affect almost any part of the body. They can

cause:
- septicaemia ( blood poisoning),
- septic shock (widespread infection of the blood that leads to a fall in blood pressure and organ failure),
- 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), - lung infection (pneumonia), and
- infection of the heart lining (endocarditis).

SA bacteria can also cause scalded skin syndrome and, very occasionally, toxic shock syndrome.