MRSA: what it is, symptoms, treatment and how it spreads

MRSA stands for meticillin-resistant Staphylococcus aureus. Patient.info explains that S. aureus (often called "staph") is a bacterium found on the skin and in the nose of many healthy people, who are called carriers. In healthy carriers it is usually harmless.

Some strains of S. aureus are classed as MRSA because they are resistant to meticillin and to many other antibiotics. The NHS describes MRSA as bacteria that usually live harmlessly on the skin but that can cause a serious infection that needs immediate treatment if they get inside the body.

Patient.info makes the point that MRSA strains are no more aggressive or infectious than other strains of S. aureus. The difficulty is that infections are harder to treat because many antibiotics do not work, and infections can become more severe if ineffective antibiotics are used first.

Most people with MRSA on their skin have no symptoms at all, according to the NHS. Patient.info calls this being a carrier or "colonised", and says the most common places are the armpits, nostrils, skin (especially with eczema), throat and urine.

If an MRSA infection develops under the skin, the NHS says you may have an area of skin that:

• is painful and swollen

• feels warm when you touch it

• leaks pus or liquid

• looks red, though this may be harder to see on brown or black skin

• If the infection spreads to your blood or lungs, or another part of the body, the NHS lists a high temperature or feeling hot, cold or shivery, difficulty breathing, dizziness and confusion.

Ask for an urgent GP appointment or get help from NHS 111 if you have a cut or wound that is painful, swollen or red, feels warm or leaks pus or liquid. The NHS says these could be signs of a skin infection such as MRSA, and that some skin infections can be serious and need to be checked quickly.

Call 999 or go to A&E if somebody has any of the following, the NHS says. Do not drive to A&E: ask someone to drive you or call 999.

• Is acting confused, has slurred speech and is not making sense.

• Has difficulty breathing, such as breathlessness or breathing very fast.

• Has blue, grey, pale or blotchy skin, lips or tongue (on brown or black skin this may be easier to see on the palms or soles).

• Has a rash that does not fade when you roll a glass over it, the same as meningitis.

Yes. The NHS says MRSA mainly spreads through touch, which can happen if you touch a person with MRSA or something they have touched. Patient.info says it is commonly passed on via towels, sheets and clothing, and by skin-to-skin contact.

Most healthy people will not become infected. Patient.info says people who are well may still carry it and pass it on, so those who visit patients or treat them are unlikely to develop an infection but may become colonised and pass it on to someone who is ill or has a wound.

Sensible steps from Patient.info include washing hands regularly, covering all cuts with a waterproof dressing, wearing gloves when in contact with a person with MRSA, and avoiding sharing towels and face cloths. The NHS says to follow hand-washing or sanitising instructions when visiting a care home or hospital.

The NHS says MRSA can be treated with antibiotics. Antibiotic tablets can be used for mild infections. More serious infections may need antibiotics given by injection or a drip into a vein in your arm in hospital. You may need antibiotics for a few days or up to a few months, depending on how serious the infection is.

Patient.info says boils or collections of pus (abscesses) caused by MRSA may only need to be drained and may not need antibiotics. It also says the choice of antibiotic is limited and many MRSA infections can only be treated with antibiotics given directly into a vein, often over several weeks.

If you get complications, the NHS says you may need further treatment such as surgery to drain a build-up of pus.

If you are only a carrier, Patient.info says you are usually offered treatment to prevent future infections and spread, in the form of ointment for the nose or antiseptic washes. This is sometimes called decolonisation.

If you are due to have surgery, the NHS says you may be offered an MRSA screening test before you go into hospital. This involves wiping swabs inside the nostril, at the back of the mouth and on the groin.

If the result shows MRSA on your skin, you will need to use a special nasal cream or spray, body wash and shampoo for around 5 to 10 days. You are sent these with instructions.

Patient.info says screening is arranged by the hospital, results usually take 3 to 5 days, and policies vary: minor procedures, day case eye surgery, children and pregnant women (unless having a planned caesarean) are generally not included. If you know you are a carrier and are due to go into hospital, let the hospital know beforehand; it will not necessarily delay or prevent admission.

MRSA infections can affect anyone, but the NHS says you may be more at risk if you:

• have long stays in hospital, especially if being treated for a serious condition

• have a break or opening in your skin, for example for a drip into a vein, a cut from surgery, a serious burn or wound, or other damage to your skin

• have a weakened immune system, for example because of a condition such as HIV or treatment such as chemotherapy

• The NHS says people staying in care homes and hospitals, especially those having surgery, are at a higher risk.

• Patient.info says it is also seen in the community, especially in nursing and residential homes, but much less commonly than in hospital patients.

The two situations are different and are managed differently, as the NHS and Patient.info describe.

It depends on whether you are a carrier or have an infection. The NHS says the skin treatment given after a positive screening swab is for around 5 to 10 days, and antibiotics for an infection may be needed for a few days or up to a few months depending on how serious it is.

Patient.info says it is still uncertain from clinical trials which carrier treatment is the most effective, so ask your hospital team what they recommend in your situation.

On the NHS, suspected skin infections are assessed by a GP or NHS 111, and hospital screening before surgery is arranged by the hospital, not the GP surgery, according to Patient.info. Serious infections are treated in hospital.

If you are having private surgery, tell the team if you know you have previously tested positive for MRSA, so that they can plan screening and infection-control measures. Patient.info advises letting the hospital know before admission.