More than 100,000 people a week are being struck down by a stomach bug which is sweeping Britain in the biggest outbreak for five years.
Norovirus, also known as winter vomiting disease, is partly to blame for the record numbers of people who failed to return to work after the Christmas break, according to doctors.
Hospitals have also been affected, with wards closed and restrictions in place.
The number of cases this year is the highest since 2002, the Health Protection Agency (HPA) said. It urged those infected with the bug, which causes diarrhoea and vomiting, to stay at home for 48 hours after their symptoms disappeared to reduce the risk of spreading the illness. Sickness appears 12 to 48 hours after infection and usually persists for 12 to 60 hours. Most people recover within a day or two.
Sufferers should stay at home after their symptoms have passed and keep away from surgeries and hospitals, the Royal College of GPs said. There is no specific treatment other than taking paracetamol and drinking lots of fluids.
Norovirus is the most common cause of infectious gastro-enteritis and outbreaks occur frequently in confined communities such as schools, offices and care homes. The virus, which is spread by contact with an infected person or contaminated surface, is not often dangerous but the very young and the elderly are at risk of complications from dehydration caused by diarrhoea.
Professor Steve Field, of the Royal College of GPs, said the number of new cases was still rising and could top 200,000 a week. "Surgeries and hospitals have been swamped with people wanting advice," he added. "Wash your hands regularly so you don't infect anyone and stay at home for two days after the symptoms have gone."
Darren Simpson, a GP in Bradford, said he had seen a large number of people with norovirus over the festive period. He said: "Very few people follow the advice on staying away from work because they have unsympathetic or nagging bosses. It is the worst time of year to catch it. Because many workplaces are understaffed owing to leave and bank holidays, there is increased pressure to attend work if you can."
In a typical year, between 600,000 and one million people catch the bug, but the norovirus season began particularly early this winter and could cost the NHS more than 100m because of the ward closures.
The number of cases in England and Wales notified to the HPA between early September and early December was 1,325, compared with 685 for the same period in 2006. However, the true number of victims is far higher perhaps as much as 1,500-fold because most do not visit their GP. A total of 1,122,874 people called the NHS Direct helpline over the 11-day Christmas and New Year holiday 61 per cent more than last year. The second-most common reason for calling was vomiting and abdominal pain. Mike Sadler, its chief officer, said: "Call patterns have been markedly different from our previous experience."Reuse content