Norovirus Guidance

  • Noroviruses and Saporoviruses belong to a larger group of viruses known as caliciviruses. They have been around for many, many years prior to the identification and naming as “Norwalk virus” or “Norovirus”,  and  previously, many have referred to the illness as the 12 hour or 24 hour “flu”.

    Calling gastro-intestinal illness “flu” creates a lot of confusion, as the true “flu,” or Influenza, is actually a respiratory virus, which only occasionally includes some gastro intestinal symptoms, particularly in young children.


Primarily, the symptoms include nausea, vomiting and diarrhea, although not everyone has all three. Body aches, headaches, and low-grade fevers are reported by some but not all. High fevers and blood in the stool are not usually seen in Noro-like illness.

For most healthy individuals, these viral gastrointestinal illnesses can be very miserable but non-life threatening. Most people recover from these infections without medical attention, but it can be more serious in the elderly, the very young, and those with compromised immune systems. The illness lasts from a couple of hours to as long as three days, and most recover in 24 hours or less. Some people have trouble keeping adequately hydrated during bouts of gastroenteritis, and may require medical attention to provide adequate replacement fluids.


Usually noroviruses are caused by ingesting food or water contaminated with the virus. Virus that is present in the vomit or stool of an infected person can be spread to others in food or water or on contaminated surfaces. Note: Norovirus, and certain other viruses can survive freezing temperatures, therefore can live in ice. It is important to treat ice like you treat food: keep it clean and free of germs and viruses!! Do not dip hands or personal containers into ice chests and ice dispensers.

It takes only very tiny amounts of this virus to make a person ill. This is why it is easy to spread it from person to person. You can accidentally get the virus on your hands from contaminated objects. If you don’t wash your hands well before preparing food, you can make yourself and others ill.

This virus can sometimes be spread in the air when ill persons vomit forcefully.


There is no medicine that treats the virus itself; since it is not a bacterial infection, antibiotics won’t work. Antiviral medication is not effective either. In cases of severe dehydration, medication to decrease vomiting or diarrhea may be prescribed. Intravenous fluids with electrolytes can also be used in severe cases. Dehydration poses the greatest threat to your health.

You may get dehydrated if you are not able to drink enough liquids to replace the fluids lost from throwing up or having diarrhea many times a day. Symptoms of dehydration include a decrease in urination, a dry mouth and throat, and feeling dizzy when standing up. Children who are dehydrated may also cry with few or no tears and be unusually sleepy or fussy. A sharp reduction in wet diapers should alert a parent to dehydration in their infant.

The best way to prevent dehydration is to drink plenty of liquids. Oral rehydration fluids are the most helpful for severe dehydration. (Think sports drinks, Gatorade, pedialyte, etc.) But other drinks without caffeine or alcohol can help with mild dehydration. However, these drinks may not replace important nutrients and minerals that are lost due to vomiting and diarrhea. If in doubt, contact your medical provider.

Prevention messages if you are ill:

  • If you should develop symptoms of nausea, vomiting, or diarrhea, please take care not to share your illness with others. Noro-like viruses spread like wildfire.
  • As always, thorough hand washing is the best way to protect others against contagious illnesses. Wash for 20-30 seconds (A long time! Have someone time you!):
    • After using the bathroom or changing a diaper
    • Before preparing food
    • Before eating food
  •  If  it is possible, consider using separate bathrooms for those who are ill so that others do not pick up virus on objects in the bathroom.
  •  Paper towels are useful to keep people from getting virus off of shared cloth towels. Paper towels are also useful to turn off the water. (Keep in mind, water taps can be contaminated surfaces, because you turn the water on using your dirty hands.) Soap dispensers with liquid soap are better than soap that sits in a puddle of water. If bar soap is all you have, be sure it sits on something that allows it to drain between uses.
  • Alcohol based sanitizers are less effective at killing this particular virus, so be sure and wash if you have the chance. Wash your hands using warm (not cold, and not hot) water. It is easier to eliminate viruses and germs from hands that don’t have jewelry or long nails.
  • Alcohol based hand sanitizers may be used in addition to washing with soap and water, but it is best not to use the sanitizer instead of washing.
  • It is also very important not to work in a setting where you handle or prepare food for others, and also be sure not to attend day care, not to work in a day care setting, and not to work in a health care setting until symptoms have resolved and ideally, 2-3 days longer. Keep in mind that you may still be contagious for a few days after you are feeling back to normal!

Prevention messages if you are taking care of others who are ill:

  • Use gloves if you should need to clean up vomit or diarrhea. Dispose of gloves and wash your hands twice when finished
  • Use bleach, at a ratio of one part bleach to 10 parts water, to clean durable surfaces and eliminate virus in the environment. Be sure to wear rubber or non-latex gloves for this job. If a bathroom is being shared between sick persons and those who are not ill, be sure to sanitize the knobs on doors, taps on the sink, and the toilet flusher and seat; do this as frequently as necessary to insure it is safe for others to use. Bleach should be mixed fresh each day, as it becomes less effective over time after it has been mixed up. Be careful to keep fresh air in the area where you are using bleach, as it may be irritating to breathe. Opening windows helps a lot. Also, be careful not to get it on clothes, carpet or upholstery. Ideally, wet things down and let sit for a few minutes to disinfect before drying the surface.
  • Laundry should be handled carefully so you don’t shake the viral particles into the air. Do not use the same basket you used to carry dirty clothes to carry them back from the laundry when clean. A plastic garbage bag is useful for transporting dirty laundry, and it will keep the hamper from harboring virus.
  • In the kitchen and dining room, avoid using shared bowls for things people pick up with their fingers, like fruit, candy, potato chips, carrot sticks etc.; it is best for everyone to be served separately when someone is sick. It is worth thinking about having someone who is not ill serving the person who has been ill, so that serving utensils etc. don’t get contaminated accidentally, where they can put others at risk who handle the same utensils.

 Prevention in absence of known illness (Everyday healthy habits):

It is not always possible to avoid noro type of illnesses, because it takes extremely small quantities of virus to sicken someone and it is difficult to wash off of foods. It’s always a good idea to wash your produce before you refrigerate it or eat it, but not everything can be made germ-free from washing. We can reduce risks with healthy habits, but we cannot ever completely eliminate risks.

Cooking will kill virus that may be on meat or vegetables, so those are always safe bets when you are eating at potlucks for instance. Food handlers are trained in ways to keep food clean and safe but potlucks, as much as we love them, are made up of food prepared by non-professionals, and this has its risks. By reading this article, you may be able to reduce the risks to others when you prepare food to share.

Hand washing is the single best method to use to avoid illness from most pathogens (viruses, bacteria, etc.)

Hand washing tips:

Clean hands are most easily achieved if you wear a minimum of jewelry on your fingers, and you keep your nails clipped short. If your nails are long, then try to do what you can to clean under the nails with every hand washing. This is somewhat difficult.

Warm water is best for achieving good lather from soap. Hot water is a poor choice because it is uncomfortable, and you will not be washing for very long in really hot water. The temperature should be comfortable enough to wash for a full 20 seconds. (This should be like singing the entire happy birthday song twice! It’s longer than you would guess!) Washing under nails, between fingers and tops of fingers and hands is necessary.

Important times to wash hands:

  • Before preparing food (protects everyone)
  • Right before touching uncooked foods, like salad, sandwiches etc. Example: you’ve washed your hands, but then handled raw meat. Wash hands again before you make your salad or cut that loaf of French bread! (protects everyone)
  •  Before touching your face, your eyes, your nose (protects self)
  • After touching your face, eyes nose (protects others)
  •  After using the toilet, even if you don’t think you touched anything dirty!! (protects self and others.)
  • After changing a diaper or helping another person to use the toilet or to clean up a mess. (protects everyone)
  • After touching an animal or animal waste. (protects everyone)
  • After touching garbage. (protects everyone)
  • After sneezing or blowing your nose or coughing. (Throw away that nasty tissue too!) –protects others.
  • Before and after cleaning a wound or touching blood. (Washing before keeps the wound clean; washing afterwards keeps any wound-germs from contaminating others.) (Protects everyone.)
  • Just the very last thing you do before you eat. Remember, surfaces may be contaminated with germs; don’t touch anything on your way to the table!

What makes Norovirus a big concern?

Norovirus-like illness becomes an issue of public health importance when people share a common source of food, or share very close living spaces. Schools, nursing homes, cruise ships, summer camps and hotels are all likely places for a norovirus outbreak. When people live in close quarters or share meals with each other, they are also likely to share illness. The role of public health is to help stop the spread of illness to others. Wide spread illness can create big impacts to individuals, families, and organizations.