Health bosses have issued a warning about norovirus amid a rising number of cases.
Public Health England have said cases are beginning to increase but advised those affected not to visit their GP or hospital to avoid spreading the infection.
A spokeswoman said that not all cases were reported as the infection passes quickly and many follow the advice to stay at home, but she warned 'numbers were starting to increase'.
Across hospitals in the north-west there were 55 confirmed cases between December 17 and December 30.
Hospitals impacted include the Royal Bolton, where eight wards were closed last week due to an outbreak.
It's understood restrictions remain on two wards - D3 and D4. Those suffering from the virus, which is said to be 'spreading in the Bolton community', are urged not visit loved ones in hospital.
For most people, norovirus lasts a couple of days. Symptoms include a sudden onset of vomiting and/or diarrhoea. Some people may have a temperature, headache and stomach cramps.
For vulnerable patients who have compromised immunity or the very young and the very old, it can be harmful.
Richard Catlin, Assistant Director of Infection Prevention and Control for Bolton NHS Foundation Trust, said: “We ask all visitors not to come into the hospital if they have had symptoms of norovirus, such as sickness and diarrhoea, within the last 48 hours. People are also urged not to come into our Emergency Department if they have had Norovirus symptoms unless it is a genuine emergency."
He said they took the virus 'extremely seriously' as it has the potential to spread very rapidly. He said admission staff were vigilant to signs of the illness so patients could be identified and managed as soon as possible.
Public Health England say reports of suspected and confirmed outbreaks of norovirus in hospitals in England are currently at lower levels than the same period in the previous five seasons.
However, Nick Phin, Deputy Director of the National Infection Service at PHE, said: “Cases of norovirus are beginning to increase although they are still at levels that we would expect to see around this time of year and over the winter period.
"For most people this is an unpleasant, short-lived illness with a full recovery within 1-2 days. It is important to drink plenty of fluids during that time to prevent dehydration especially in the very young, elderly or those with weakened immunity.
"We advise people not to visit GP surgeries and hospitals with symptoms as this can spread the infection, however, if they are concerned they should contact NHS 111 or talk to their GP by phone."
He said one of the best ways to protect against the virus was to practise good hygiene - including thorough hand washing with soap and warm water after using the toilet and before preparing food.
Manchester University NHS Foundation Trust - which covers the MRI, Wythenshawe Hospital, Royal Manchester Children's Hospital, Manchester Royal Eye Hospital, Saint Mary's University Dental Hospital of Manchester, Withington, Trafford General and Altrincham - have not had any outbreaks.
However, a spokeswoman for the trust was unable to confirm how many individual cases had been reported.
A spokesman for the Stockport NHS Foundation Trust said they had not had any reported cases of norovirus.
The Northern Care Alliance NHS Group, covering Salford Royal, Royal Oldham, Fairfield General, Rochdale Infirmary and North Manchester General, said there had been no outbreaks but failed to confirm if there were any individual cases.
Wrightington, Wigan and Leigh NHS Foundation Trust has not had any reported cases of norovirus since the end of November.
A spokeswoman confirmed they closed two ward around November 29 after a confirmed case on their Winstanley Ward. This ward was closed, as well as a neighbouring one as a precaution.
A Christie spokeswoman confirmed they had had no cases of norovirus.
The issue comes as winter takes hold and hospitals deal with high numbers of patients.
Greater Manchester Health and Social Care Partnership says trusts preparing for one of the busiest weeks of the year amid colder weather and an increased prevalence of viruses.
In the week to December 30, there were 24,730 A&E attendances, with no A&E closures.
But there were four A&E diverts for ambulance patients, lasting up to three hours. These happen when departments are too busy to accept new patients.
In the week to December 30 there were 11,664 ambulance calls.
People are advised to follow these simple steps to help avoid Norovirus
Take plenty of fluids
Wash your hands regularly with soap and water
Keep yourself away from others – especially from GP surgeries or hospitals
If your symptoms continue for more than two days seek advice from NHS 111 by calling 111 on your phone or visit the NHS website for further information.
For non-emergencies, people can contact NHS 111 for further advice by calling 111.
What is Norovirus?
Norovirus is just a stomach bug, but it can be very nasty and causes diarrhoea and vomiting.
It is sometimes known as the "winter vomiting bug" because it's more common at this time of year, although you can catch it year round.
As unpleasant as it is, it usually clears up after a few days.
Should you visit the GP?
No, Norovirus can spread to others very easily so visiting the GP can often do more harm than good. If you are worried though, you can call your GP or the NHS 24 '111' service if you're concerned or need any advice.
What are the symptoms?
The symptoms of Norovirus are very distinctive.
You're likely to have Norovirus if you experience:
- suddenly feeling sick
- projectile vomiting
- watery diarrhoea
Some people also have a slight fever, headaches, painful stomach cramps and aching limbs.
The symptoms appear one to two days after you become infected and typically last for up to two or three days.
Sadly, there isn't too much you can do to help get rid of Norovirus, there is no cure but doing these things can help:
- drink plenty of fluids to avoid dehydration. You need to drink more than usual to replace the fluids lost from vomiting and diarrhoea – as well as water, adults could also try fruit juice and soup.
- take paracetamol for any fever or aches and pains.
- get plenty of rest.
- if you feel like eating, eat plain foods, such as soup, rice, pasta and bread.
- use special rehydration drinks made from sachets bought from pharmacies if you have signs of dehydration, such as a dry mouth or dark urine – read more about treating dehydration.