The U.K. is dealing with an outbreak of the so-called vomiting virus that is expected to infect hundreds of thousands of people in the coming weeks.

More than 70 hospital wards across the U.K. have been closed to new patients and visitors in an attempt to contain the spread of the norovirus.

Symptoms of the virus include nausea, projectile vomiting, diarrhea, fever and muscle pain.

While it is already the most common stomach bug in Britain, the U.K.'s Health Protection Agency (HPA), says doctors and hospitals are seeing the highest incidence of the illness since 2002.

Normally, between 600,000 and one million people catch the stomach bug every year in Britain, the National Health Service (NHS) says on its website.

However, during just an 11-day period in late December, at least 1.1 million people had already called the NHS helpline reporting symptoms.

Officials believe figures are actually higher than currently estimated because many who get the virus fail to seek medical attention.

Doctors estimate at least 100,000 people a week are catching the bug, reports the BBC.

People suffering from the virus are being asked to stay away from local hospitals and to refrain from going to work for at least 48 hours after symptoms subside.

The virus, which is short-lived, presents the most danger for the elderly and young children because of complications from dehydration.

Hospital closures

The Worcestershire Acute Hospitals Trust in England has cancelled non-emergency surgeries until Jan. 9 because of "unrelenting pressure" caused by the outbreak, the BBC reports.

Fifteen wards have been closed in the Greater Manchester area, while one ward at Lurgan Hospital has been closed for a month after an outbreak across Northern Ireland.

Medical officials estimate closing the wards during an epidemic season could cost the NHS roughly $200 million, CTV's London Bureau Chief Tom Kennedy said Friday.

Outbreaks of the virus often occur in hospitals, on cruise ships and in other areas where people gather for extended periods of time.

The norovirus is usually found in the vomit or stool of an infected person.

The Public Health Agency of Canada reports individuals can become infected in a number of ways including:

Eating food or drinking liquids that are contaminated with norovirus;

Touching surfaces or objects contaminated with norovirus;

Having direct contact with another person who is infected and showing symptoms.

Dr. Paul Sockett, a spokesperson with the Public Health Agency of Canada, told CTV.ca that norovirus is very different virus from influenza, which it is commonly mistaken for.

"The stomach flu does not exist, it's a convenient term for having this type of acute stomach upset," he said.

"Basically norovirus is gastroenteritis, it's diarrhea and vomiting sometimes with a bit of fever, where as influenza is very much a respiratory disease that affects the upper respiratory tract."

The PHAC recommends travellers and people living in an area where there is an outbreak should wash their hands regularly and use a bleach-based cleanser if they come in contact with an episode of illness.

"Travellers can transmit the illness during the acute stage of the illness and up to 72 hours after symptoms disappear. This risk should be considered when travelling on common carriers such as buses, trains, airplanes, ferries and cruise ships, and when preparing food," the PHAC reports.

Sockett warns that the virus can also spread through contaminated food "either because somebody handling the food has the disease while they're handling it or shellfish can sometimes actually trap the virus."

Canadian health officials report an average of 300 to 400 outbreaks, which are categorized by two or more people linked by a common exposure within a specific time frame, a year since 2002.

Sockett notes the number of outbreaks in Canada have steadily increased since 2002, in part, because of improved technologies in diagnostic testing and an increase in reporting of norovirus cases.

"Certainly 2002 was a big year for us and the winter of 2006 and 2007 we also saw a significant number of outbreaks occurring," he said.