Four wards at Bradford Royal Infirmary have been hit by winter vomiting disease.

Hospital bosses have imposed restrictions on staff movements and are not accepting any new admissions to the wards in a bid to prevent further spread of the disease.

The latest outbreak follows the closure of ward nine at BRI in October when it was hit by a similar infection, which causes vomiting and diarrhoea.

Winter vomiting disease - norovirus - is the most common cause of infectious gastroenteritis in England and Wales.

Although relatively mild, norovirus illness can occur at any age because immunity to it is not long lasting.

The disease is known as winter vomiting disease due to its seasonality and symptoms.

Outbreaks of norovirus gastroenteritis are common in semi-closed environments such as hospitals, nursing homes, schools and cruise ships.

A spokesman for Bradford Teaching Hospitals NHS Foundation Trust said: "Cases of diarrhoea and vomiting are not uncommon in hospitals, particularly during the winter months. Four of our wards are currently affected by this illness. We have put several restrictions in place to help combat any spread of infection, such as restricting staff movements where possible and not accepting new admissions on these wards. We have also put in place enhanced cleaning and advised patients' relatives to limit visiting."