Norovirus Guidance

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

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.


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.

Transmission & Treatment:

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.

There is no medicine that treats the virus itself. 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.

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:

  • Thorough hand washing is the best way to protect others against contagious illnesses. Wash for 20-30 seconds:
    • After using the bathroom or changing a diaper
    • Before preparing food
    • Before eating food
  • Use separate bathrooms for those who are ill so that others do not pick up virus on objects in the bathroom. Disposable paper towels are preferable to cloth towels. Soap dispensers with liquid soap are preferable to bar soap.
  • 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 sanitizers are less effective at killing this particular virus.
  • If you work in food preparation, child care, or health care, stay at home until 48 hours after symptoms have resolved. Avoid cooking meals for family members until 48 hours after symptoms have resolved.

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.
  • Handle laundry carefully. 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 finger food.