Norovirus affects 750,000 Britons

Visitors are being turned away from hospitals across Britain as the deadly norovirus, commonly known as the "winter vomiting bug", is believed to have affected 750,000 people.
The Birmingham City Hospital has asked visitors to stay away after closing four wards while the Maidstone Hospital in Kent has shut three wards to new admissions and banned visitors from all wards, Sky News reported.
The George Eliot Hospital in Nuneaton is also turning away visitors. Five hospitals in Wales are also closed to people other than patients.
The number of cases affected by the winter vomiting bug is up 72 percent than during the same period last year, the Health Protection Agency said.
This season, 2,630 cases have been recorded, while last year, there were just 1,533 cases.
The agency said that for every confirmed case there are likely to be a further 288 unreported sufferers.
This means 750,000 people could have been struck down by the bug across Britain.
Norovirus is a highly contagious bug and spreads quickly in close environments such as hospitals and schools.
The symptoms include vomiting and diarrhoea, which usually last for around two days.
A cruise ship Azura, docked in Southampton and carrying 3,059 passengers, has also reported an outbreak of the virus on board.
The ship was on an 11-night cruise. Officials confirmed there were 10 cases and those passengers had been confined to their cabins to prevent its spread.
Around 300 people on another ship Oriana were also hit by the virus during a cruise.