11/29/2016 05:13 EST | Updated 11/29/2016 05:13 EST

4 Things To Know About Norovirus


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Written by Sybil Millar, Communications Advisor for the Ross Tilley Burn Centre, Critical Care and Infectious Diseases programs at Sunnybrook.

Winter is here -- and so is norovirus, the illness that can quickly spread among groups of people, shutting down schools and sending cruise ship passengers into quarantine. With the recent news of norovirus outbreaks in the GTA, it's important to understand how the virus spreads and how to protect yourself against contracting the illness. We spoke with our expert Dr. Andrew Simor, head, department of microbiology and infectious diseases consultant at Sunnybrook, to learn more:

1) It's highly contagious, so wash your hands

Norovirus is highly contagious; in fact, "it's the most common gastrointestinal infection, and you only need to ingest a small amount of the virus to become ill," says Dr. Simor. The most effective way to avoid getting it is also one of the easiest things to do: practice good hand hygiene. This can mean washing your hands with soap and water or using an alcohol-based hand sanitizer, especially when handling food. Both are effective at removing (washing) or killing (hand sanitizer) bacteria and viruses.

Hand sanitizer should contain alcohol at a minimum concentration of 60 per cent to be effective. Many people find alcohol-based hand sanitizer to be a convenient way to clean hands, especially in public places where hand washing sinks with soap and water are not always available. Keep an alcohol-based hand sanitizer in your purse, pocket or backpack.

2) It's primarily spread through the fecal-oral route

Norovirus is primarily spread when hands become contaminated by touching a person with the virus. This can happen after shaking hands with someone who has been vomiting or had diarrhea (and who hasn't washed their own hands after using the bathroom), or by touching a surface or consuming food that is contaminated with the virus. When a person has projectile vomiting, droplets of vomitus can become aerosolized and can directly transmit virus to someone near the vomiting person.

3) No matter how many times you get it, you won't become immune

Just because you get norovirus once, doesn't mean you can't get it again. In fact, it's entirely possible, and it does happen. "There are many viral strains of norovirus, but after being ill with one strain of the virus, you won't have developed any long-lasting immunity, even to the same strain you were already exposed to," says Dr. Simor.

4) The best (and only) treatment: stay hydrated

If you do get norovirus, some of the symptoms to look out for include an upset stomach, vomiting, diarrhea, stomach pain and a loss of appetite. "It usually lasts for one or two days, but unfortunately, there's no treatment for norovirus beyond making sure you're getting enough fluids," says Dr. Simor. While norovirus can affect people at any age, the elderly are at higher risk for complications, including dehydration.

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