Experts at West Yorkshire Health Protection Unit have urged people in Keighley not to visit relatives and friends in hospital or care homes if they have the norovirus illness.

They say the sickness — which includes diarrhoea, vomiting, nausea, headache and fever — is showing signs of an increase.

Norovirus is also known as the winter vomiting disease.

It is the most common cause of infectious gastroenteritis in England and Wales, especially during winter.

A health protection unit spokesman said: “We are aware of an increase in the number of suspected cases of the virus across the county in recent weeks.

“We are advising that children showing signs of the virus following the Christmas holidays, should be kept away from school and not return for 48-hours after they have recovered.”

He emphasised the importance of good hygiene measures, as the virus was highly infectious and spreaded easily from one person to another, particularly in schools, nursing homes and hospitals.

Dr Mike Gent, interim director of the unit, said: “Unfortunately, there is no specific treatment for the virus, apart from letting the illness run its course and so, in the vast majority of cases, there is no additional benefit to visiting a GP or A&E.

“It’s important to drink plenty of fluids to prevent dehydration, especially in the very young or the elderly.

Further information on norovirus can be found at hpa.org.uk/infections/topics_az/norovirus/menu.htm