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Norovirus Canada: 10 Things You Need To Know About 'Winter Vomiting Disease'


With violent strains of the flu sweeping across North America and lesser coughs and colds making their rounds of offices, Canadians have discovered another illness to worry about: Norovirus.

The virus, which is actually a group of viruses that are the most common cause of epidemic gastroenteritis, has been bandied about in the past as an interchangeable term for the stomach flu, but the phrasing can be incredibly misleading for the public.

"The flu is a respiratory virus, while noro takes place in the gastrointestinal system," explains Dr. Gerald Evans, a professor of medicine, biomedical and molecular sciences at Queen's University, and the medical director for infection prevention and control at Kingston General Hospital. "You don't get a cough and you don't get a sore throat with norovirus."

Once known as 'winter vomiting disease' and characterized by nausea, vomiting and diarrhea, norovirus tends to take place seasonally, coming on very suddenly and lasting for approximately 24 to 48 hours. As winter sets in and people stick to the indoors — without fresh air circulating via open windows — the virus is more likely to spread.

We asked Dr. Evans to explain the basics of the illness, how it spreads and what, if anything, you can do to prevent it.

SEE: The 10 things you need to know about norovirus:

10 Things To Know About Norovirus

Where Does It Come From?

The virus is spread through an infected person's feces or vomit, and often by unwashed hands. "It's not that it's in food, but more often than not, it's in the environment," says Dr. Gerald Evans, a professor of medicine, biomedical and molecular sciences at Queen's University, and the medical director for infection prevention and control at Kingston General Hospital. "You don't want to know how much stuff from people's intestinal tracts is all over the environment."

Where Can You Get It?

The most common places for norovirus to spread are residences where many people are living together — nursing homes, for example, or cruise ships.

What Are The Symptoms?

The clinical syndrome is characterized by nausea, vomiting and diarrhea, though for some, it can also include a fever and abdominal pain. It comes on very suddenly — usually within 10 hours of transmission — and lasts one to three days. After three days, it's no longer contagious.

Who's At Risk?

Anyone can get norovirus, but it can be a particularly bad illness for the very young, and the very old. "Healthy people who get it feel awful, but they recover quickly," says Dr. Evans. "The problem is when it combines with other ailments. For very old people who might have other health problems, it can have serious effects, while very young people can dehydrate much more quickly."

Interestingly, the virus particularly likes people with the blood group O, which constitutes about 45 per cent of the population. This is thanks to the receptor the virus attaches itself to. If you have another blood type, you can still get norovirus, but the disease will likely not be as severe.

What Can You Do If You Contract Norovirus?

"Lay low and wait for yourself to get better," advises Dr. Evans. There's no treatment, and while medical professionals advise keeping fluids up, Dr. Evans acknowledges this can be difficult, given the nature of the illness. "We want people to try to hydrate themselves as best they can, but it can hard," he says. "Because it's usually just one day, the situation doesn't get too dire, but every so often, we see perfectly healthy adults coming into the emergency room for intravenous fluids to get hydrated again."

What Can People Do To Protect Themselves?

You'll want to practice good hygiene in order to reduce the possibility that you'll ingest the virus, recommends Dr. Evans, and of course, try to avoid being in a circumstance where you can get the virus. "We really encourage handwashing, but I won't tell you will absolutely not get sick if you wash your hands," he says. "Viruses are tiny little particles, and it doesn't always matter how fastidious you are at cleaning things — they get everywhere."

Why Is It Such A Concern?

The biggest problem, notes Dr. Evans, is that the virus is very transmissible, and can easily pass from person to person. It's also quite the trial on your health.

"It's very traumatic," says Dr. Evans. "It's amazing how fast it starts, and it's amazing how bad you feel for at least a day or two. Most people who get it would rather have anything else."

What Is The Difference Between Norovirus And The Flu?

The flu is an entirely different illness than norovirus. As Dr. Evans explains, the flu takes place in the respiratory system, while norovirus is a gastroenterological illness. Besides the lack of cough and cold in norovirus, it also has a much short lifespan: Three days vs. the flu's five to seven-day stint.

What Is The Difference Between Norovirus And Norwalk?

Norwalk is an old term for norovirus, says Dr. Evans. "Viruses are always named geographically, and the first norovirus was discovered in Norwalk, Ohio, so it was given that name. It's been since changed to give the group of viruses the name 'norovirus.'"

Are There Any Long-Term Effects?

"As far as we know, there are no long-term effects — it's a very self-limited illness," says Dr. Evans. "The biggest, scariest thing about noro is that you're never immune to it, because there are a bunch of different strains. Once you get it, you can pretty well guarantee you will get it again."

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