What is Norovirus? How Serious is This Infection?

Norovirus is a stomach and intestinal virus that’s very contagious. It passes easily through direct or indirect contact with an infected person. It can spread quickly in close quarters such as hospitals, schools, and day care centers.

Most people have some experience with norovirus. It’s a common illness of the stomach and intestinal tract. Norovirus can also be a source of food poisoning, because you can get it from eating contaminated food. The results are the same no matter how you get it.

The hallmark symptoms of norovirus are vomiting and watery, non-bloody diarrhea. These symptoms usually start within 12 to 48 hours of being exposed and can last up to three days. Most people make a full recovery.


There’s no specific treatment except to rest and rehydrate. The most significant complication is dehydration. Norovirus can be serious and even fatal in the very young, older adults, and people with other health problems.

Because there are many norovirus strains, having it once doesn’t prevent you from getting it again. You can lower the risk of disease transmission by washing your hands thoroughly and frequently.

Norovirus is thought to be the most common cause of acute gastroenteritis in the world, leading to 685 millionTrusted Source cases a year. Gastroenteritis is inflammation and infection of the stomach and intestinal tract caused by any infectious organism, like bacteria and viruses. Norovirus is responsible for up to 21 millionTrusted Source illnesses in the United States each year.

Symptoms of infection usually start somewhere between 12 and 48 hours after you’ve been exposed to the virus. They can range from quite mild to severe. Some signs and symptoms of norovirus are:

Symptoms usually last between 24 to 72 hours. See your doctor if symptoms persist beyond that or if you see blood in your stools. Severe diarrhea can lead to dehydration, which should be considered a medical emergency. Signs and symptoms of dehydration include:

  • dry mouth and throat
  • decreased output of urine or dark urine
  • no wet diaper for 6 to 8 hours in infants
  • no urine in 12 hours for children
  • sunken eyes
  • sleepiness and fatigue
  • headache
  • dizziness
  • confusion and lethargy
  • rapid heart rate

If your child cries without producing tears, that’s a common sign of significant dehydration. Seek medical care right away. They might also act fussy and irritable.

Dehydration can be life-threatening, especially for the following groups:

  • people with a weakened immune system
  • people with preexisting health conditions
  • the very old and the very young
  • organ or stem cell transplant recipients

It’s estimated that in some cases, about 30 percentTrusted Source of the time, the virus causes no symptoms at all. This is especially common in children.

There’s no special medicine for norovirus. It’s not a bacterial infection, so antibiotics won’t help. Treatment is mainly supportive, with a goal of preventing dehydration. Here are some self-care tips:


Don’t push yourself. Stay home and rest.

Replenish fluids

Drink plenty of fluids. To replace electrolytes, oral hydration solutions, like Pedialyte, are recommended for all ages. They’re especially necessary in infants and children.

Sports drinks, popsicles, and broths should only be taken by older children and adults. Stay away from sugary drinks, as these can worsen diarrhea. You should also avoid drinks that contain caffeine or alcohol.

Continue your diet

Infants should continue breastfeeding or formula feeding while being rehydrated.

For children and adults, as appetite picks up, some good choices are:

  • soups
  • plain noodles
  • rice
  • pasta
  • eggs
  • potatoes
  • crackers or bread
  • fresh fruit
  • yogurt
  • Jell-O
  • cooked vegetables
  • lean proteins like chicken and fish