Norovirus: Prevention and risks
On this page
- How norovirus spreads
- Preventing norovirus
- Risks of getting norovirus
- Who is most at risk
- Recommendations for travellers
How norovirus spreads
The stool and vomit of infected and recently recovered people contains norovirus. The virus spreads very easily and quickly from person to person. It only takes a few virus particles to make someone sick.
Infected people are most contagious:
- while they have symptoms, and
- for at least 3 days after they have recovered
Some people continue to be contagious for up to 3 weeks after recovery.
You can get norovirus by:
- sharing food or utensils with an infected person
- having direct contact with or caring for an infected person (including diapering and cleaning vomit or diarrhea)
- touching a contaminated surface and then touching your mouth before washing your hands
- eating contaminated food or drinking contaminated liquids
Food can get contaminated with norovirus when:
- it's handled by a person who's infected
- it comes into contact with contaminated water while being grown, produced or harvested
Water can get contaminated with norovirus by sewage, leading to waterborne outbreaks.
Preventing norovirus
It can be hard to prevent norovirus infections because contaminated foods and beverages look, smell and taste normal.
You can protect yourself and your family from norovirus by following these precautions:
- wash your hands with soap and water:
- after using the washroom or changing diapers
- before preparing or eating food
- clean and disinfect surfaces after an episode of illness
- immediately wash clothing and linens that are soiled with vomit or diarrhea
- cook shellfish thoroughly before eating, especially oysters and clams
- wash raw fruits and vegetables thoroughly with clean running water before you prepare and eat them
- drink water from a safe (treated or boiled) water supply
- follow general food safety practices
If you've been diagnosed with a norovirus infection or suspect that you have one, you can help prevent the spread of illness by:
- practicing proper hand hygiene
- not preparing or serving food or drink to others
- not caring for others until 3 days after you recover
- avoiding others until you are well again
Risks of getting norovirus
Noroviruses are common worldwide and can infect people of all ages. Outbreaks can occur at any time but are most common in the fall and winter.
Most outbreaks occur in settings where people are in close contact, such as:
- schools
- hospitals
- cruise ships
- nursing homes
- passenger trains
- childcare facilities
- food service settings
Who is most at risk
Although norovirus can infect anybody, you're at higher risk of a more severe case if you:
- are pregnant
- are a young child
- are elderly
- have a weakened immune system
Recommendations for travellers
In addition to the general recommendations that apply to everybody, travellers should only drink treated or boiled water from a safe source, or from a commercially sealed bottle.
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