"NOROVIRUS – it's often called the 'winter vomiting virus' and it arrives every year. It can affect all of us, but can be serious for the elderly and the young.

So what is it and why can it have such a devastating effect?

Quite simply it's a particular strain of diarrhoea and vomiting, or infectious gastroenteritis. It can happen at any time of the year, but mainly affects us in the winter.

Did you know Norovirus can be more infectious than the common cold?

That is why it can be such a problem in semi-closed environments such as hospitals, nursing homes, schools and cruise ships. We don't have many cruise ships in North Staffordshire, but we do have the rest.

At the moment lots of under-fives are suffering with Norovirus, which means their families are exposed to the bug and are likely to become carriers even if they don't go down with it themselves.

How do you know if you have Norovirus?

It's probably best not to be eating while you read this next bit – you may have a sudden onset of nausea and sometimes vomiting, which may be projectile. Other symptoms are watery, uncontrollable diarrhoea that is offensive-smelling.

Some people may also have a raised temperature, headaches and aching limbs and will feel generally unwell.

All this is very unpleasant for the sufferer and those around, but it is not usually life-threatening and most people can look after themselves quite successfully at home.

Usually you won't feel much like eating, but it is important to drink plenty of fluids so you don't get dehydrated. It doesn't have to be just water. Tea, coffee and juice drinks are all fine. And you don't have to drink a whole cupful in one go – regular sips will do the trick if that is all you can manage.

While you're battling the symptoms of Norovirus it's important to take steps to stop it spreading. The first thing to do is stay at home. Please don't go to work out of a misplaced sense of duty as you will certainly pass it on to your colleagues and that will make things much worse for them.

To try and stop anyone else in your family picking up the bug, make sure you clean carefully, particularly the bathroom and toilet area. If possible, it's a good idea to keep one toilet reserved for the sufferer but, if that's not possible in your house, you must clean well after each use.

Everyone else in the house can help protect themselves by washing their hands thoroughly with soap and water after contact with an infected person, after visiting the toilet and before handling food or crockery.

Most people daren't go too far from a toilet to risk going out at all but, as you start to get better, you may be tempted to nip out to the shop or fetch the children from school. Please don't – you need to wait 48 hours after your symptoms have gone away before you are no longer infectious.

Most people will get over Norovirus quite quickly if they stick to this advice.

If you don't improve after three days though, you should ring your GP.

Only on rare occasions do sufferers need to go to hospital.

Going to hospital unnecessarily just means the bug will be passed on to other vulnerable patients and staff.

At the moment a number of wards at University Hospital are closed because of Norovirus. This does not mean the wards are empty. It means a number of patients and staff on the wards have the bug so we take steps to clear it.

We don't put new patients on the ward and we don't send any patients from there to a different ward, to another hospital or to a residential or nursing home. We can, however, send patients to their own home if they are well and don't have the virus.

As you can imagine, we have a very strict cleaning regime and, once the ward is clear of the virus, we do a deep clean before new patients are admitted.

If we have three wards closed we restrict visiting to one hour a day on all wards (except intensive care, children's and maternity wards). This might seem Draconian, but it reduces the chances of Norovirus being brought in to the hospital and it allows more time for extra cleaning and looking after the affected patients.

We don't do this lightly because we understand you want to spend time with a sick relative. That is why we always lift the restriction as soon as we can, even if we have to bring it in again later.

Don't risk Norovirus this Christmas. If you're affected, stay at home. If you're really unwell ring your GP or NHS Direct on 0845 4647 and, whatever you do, don't attend any hospital appointments or visit anyone in hospital if you or someone in your home has the virus.

Eleven hospital wards were closed to new patients today following an outbreak of the winter vomiting bug.

The beds at the University Hospital of North Staffordshire are off limits to new admissions, because of the Norovirus infection. Restrictions have also been placed on visiting hours, which have been cut to one hour a day from 6.30pm.

People who have been in contact with the virus are being urged to stay away from the hospital.