THE Health Protection Agency (HPA) has issued advice on measures to quell the spread of norovirus infection, which tends to peak at this time of the year.

The so-called winter vomiting disease, an outbreak of which hit the Countess of Chester Hospital in recent weeks, affects 600,000 to 1,000,000 people in the UK each year.

Professor Martyn Regan, the HPA North West's lead regional epidemiologist and specialist in gastrointestinal infections, says there are measures people can take to protect themselves and prevent the spread of infection.

He explained: 'Thorough hand-washing is the key to preventing the spread of norovirus and many other infections, so people should take great care with basic hygiene.

'Anyone who is ill with norovirus should avoid mixing with others and handling food.'

People in semi-closed environments such as hospitals, residential care and nursing homes and schools are particularly vulnerable to the spread of infection.

Dr Bob Adak, who monitors norovirus for the HPA, said: 'Norovirus is easily transmitted. However, the illness is self-limiting. The symptoms will last for 12 to 60 hours and will start with sudden nausea followed by projectile vomiting and diarrhoea.

'There are a number of measures that people can take to prevent the spread of infection. Good hygiene is important in preventing others from becoming infected - especially hand-washing after toilet visits.

'Contaminated surfaces and areas should be thoroughly disinfected after an episode of illness and food preparation should be avoided until three days after the symptoms have gone altogether.'