THE norovirus outbreak at two hospitals is of “significant” proportion.

Five wards at Huddersfield Royal Infirmary are currently affected by an outbreak of the norovirus stomach bug.

A further two wards at Calderdale Royal Hospital in Halifax are also closed off.

The stomach bug causes vomiting and diarrhoea among sufferers and is easily spread.

It led to hospital staff asking unwell friends and relatives of patients to stay away.

David Birkenhead, director of infection prevention and control, said: “Since the national outbreak of gastroenteritis in November 2007 most hospitals across the country have been dealing with cases of diarrhoea and vomiting, caused by a virus known as norovirus.

“The outbreaks have varied week on week from a single patient being isolated and treated in a sideroom or, in the worst cases, several wards affected at once.

“Locally we are currently seeing a peak in cases with two wards at Calderdale Royal Hospital affected and five at Huddersfield Royal Infirmary.

“We take every measure possible to try to stop the spread of this highly contagious stomach bug and also work closely with our partners, for example GPs and the primary care trusts.

“But we also try to emphasise to our visitors that it is vital they stay away from hospital if they have any symptoms of sickness and diarrhoea.”

Norovirus is most common in winter but is not unusual at this time of year. Outbreaks are common in hospitals, schools and workplaces.

Earlier this year around 100,000 people were affected by the bug nationally, with hospitals closing wards to stop it from spreading.

Tim Barton, from the NHS Strategic Health Authority in Yorkshire, said: “Seven wards affected is significant for them but we are not changing the way the NHS functions as a response to it.

“NHS hospitals across Yorkshire and Humber have occasional incidences of norovirus.

“We have well established procedures for managing these incidences and minimising any short-term impact on patient care.”

As a matter of urgency, patients were isolated from others once the virus was detected.

In this case, as more than one person has the virus, restrictions were put in place preventing anyone from leaving the affected areas.

A spokeswoman for the Calderdale and Huddersfield NHS Trust said the trust has stepped-up its cleaning procedure.

Some patients in Huddersfield on the medical assessment unit, the surgical unit and two elderly care wards, six and seven, were hit by the virus.

Orthopaedic wards 19 and 20 at HRI were also affected.

Director of nursing Helen Thomson said: “Residents can rest assured we are tackling the problem and if they need a hospital bed one will be available.”