Health chiefs at Northampton General Hospital have issued a warning about the winter vomiting bug after reports of an outbreak in a nearby town.
In a post issued on Facebook no Thursday night, the hospital said there had been reports of norovirus in Milton Keynes.
A spokesman said: "We're asking for your help in making sure it doesn't spread to us here at NGH.
"Spread the word and not the bug. If you have signs or symptoms of the virus (sickness or diarrhoea) please stay away and don't visit hospital until you have been clear of symptoms for at least 48 hours.
"Keep your hands clean by washing them regularly Remember - norovirus spreads very quickly - it is easily spread from one person to another.
"It can be transmitted by contact with an infected person, by consuming food or water, or by contact with contaminated surfaces or objects.
"Did you know that the infection dose is very low, swallowing as few as 10 to 100 virus particles may be enough to cause illness. So, please help us so we can help you."
Norovirus is the leading cause of gastroenteritis, an unpleasant inflammation of the digestive system.
Though it isn’t life-threatening, it is a rough ride for those who catch it. Symptoms include diarrhoea and projectile vomiting, fever, headaches and aching limbs.
They tend to clear up within two days, although the very young and very old may get dehydrated and need hospital care.
The bug is highly contagious. It spreads through contact with an infected person or contaminated object, including food. It often breaks out in offices, hospitals and schools, and hits much harder in the winter – hence its unflattering nickname, “the winter vomiting bug”.