Norovirus: What is it & What to do When You are Sick

What is Norovirus?

Norovirus is a highly contagious virus that causes sudden vomiting and diarrhea. Noroviruses are highly contagious.  Although it's often referred to as a "stomach bug" or "stomach flu," it's not related to the flu.  A Norovirus infection causes acute gastroenteritis, an inflammation of the stomach or intestines.

What are the signs and Symptoms of Norovirus?

Signs and symptoms of Norovirus infection may start suddenly and can include:

• Nausea
• Vomiting
• Stomach pain or cramps
• Watery or loose diarrhea
• Body aches
• Headache
• Low-grade fever

Norovirus illness can cause you to feel extremely ill and vomit and or have diarrhea many times a day. This can lead to dehydration (loss of body fluids), especially in young children, older adults, pregnant people, and people with medical conditions. Symptoms of dehydration can include:

• Decreased urination
• Dry mouth and throat
• Feeling dizzy when standing up
• Crying with few or no tears
• Unusual sleepiness or fussiness

How long does a Norovirus infection last?

Norovirus symptoms such as diarrhea, stomach pain and vomiting typically begin 12 to 48 hours after exposure.  Most people with Norovirus illness feel better within 1 to 3 days.  Most people recover completely without treatment. However, for some people, including young children, older adults, pregnant people, and people with other medical conditions, vomiting and diarrhea can be severely dehydrating and require medical attention.

When to seek medical attention for Norovirus?

For most people, Norovirus infection usually clears up within a few days and isn't life-threatening. However, for some people, including young children, older adults, people with weakened immune systems or other medical conditions and pregnant people, Norovirus infection can be severe. Norovirus infection can cause severe dehydration and even death.

Seek medical attention if you develop diarrhea that doesn't go away within several days. Also call your health care provider if you experience severe vomiting, bloody stools, stomach pain or dehydration.  Severe dehydration may require hospitalization for treatment with fluids given through your vein (intravenous or IV fluids). If you think you or someone you are caring for is severely dehydrated, call your doctor.

Spread & Prevention

How does Norovirus spread?

Norovirus is very contagious and spreads very easily and quickly in different ways.

• Contaminated food:
  • Norovirus can spread through contaminated food when:
    • A person with Norovirus touches food with their bare hands.
    • Food is placed on a counter or surface that has poop or vomit particles on it.
    • Tiny drops of vomit from a person with Norovirus spray through the air and land on the food.
    • Food is grown with contaminated water (like oysters), or fruit and vegetables are watered with contaminated water in the field.
• Contaminated water:
  • Recreational or drinking water can get contaminated with Norovirus:
    • At the source such as when a septic tank leaks into a well.
    • When a person with Norovirus vomits or poops in the water.
    • When water isn't treated properly, such as with not enough chlorine.
• Contaminated surfaces:
  • Norovirus spreads through sick people and contaminated surfaces when:
    • A person with Norovirus touches surfaces with their bare hands.
    • Food, water, or objects that are contaminated with Norovirus are placed on surfaces.
    • Tiny drops of vomit from a person with Norovirus spray through the air, landing on surfaces or entering another person's mouth.
    • A person with Norovirus has diarrhea that splatters onto surfaces.

How long are you contagious with Norovirus?

You are most contagious:

• When you have symptoms of Norovirus illness, especially vomiting.
• During the first few days after you feel better.

However, studies have shown that you can still spread Norovirus for 2 weeks or more after you feel better.

How can you prevent the spread of Norovirus?

Norovirus infection is highly contagious. There are many types of Noroviruses. Anyone can get Norovirus infection more than once.

To prevent Norovirus infection:

• Wash your hands well:
  • Wash your hands often with soap and water for at least 20 seconds, especially:
    • After using the toilet or changing diapers.
    • Before eating, preparing, or handling food.
    • Before giving yourself or someone else medicine.
• Hand sanitizer does not work well against Norovirus:
  • You can use hand sanitizers in addition to hand washing, but hand sanitizer is not a substitute for handwashing.  Handwashing is more effective at preventing the spread of Norovirus than hand sanitizer.
• Handle and prepare food safely:
  • Before preparing and eating your food:
    • Carefully wash fruits and vegetables well.
    • Cook oysters and other shellfish thoroughly to an internal temperature of at least 145°F.
    • Routinely clean and sanitize kitchen utensils, cutting boards, counters, and surfaces, especially after handling shellfish.
    • Keep raw oysters away from ready-to-eat food in the grocery cart, refrigerator, and on cutting boards.
    • Throw away food that might contain Norovirus.
• Disinfect surfaces that might have been contaminated:
  • Wear gloves and use a chlorine bleach solution or a disinfectant that is effective against Noroviruses.
• If you have Norovirus, stay home from work. Children should stay home from school or child care.
• Avoid traveling until 2 to 3 days after your symptoms are gone.
• Dispose of vomit and stool carefully:
  • Wearing disposable gloves, soak up material with disposable towels. Disturb soiled material as little as possible to avoid spreading Noroviruses by air. Place soiled items in plastic bags and place them in the trash.
  • Remove and wash clothes and linens that may be contaminated.  Wash the items with detergent and hot water at the maximum available cycle length and then machine dry them at the highest heat setting.

Treatment & Self care

What is the treatment for Norovirus?

There's no specific treatment for Norovirus infection. In most people, the illness usually resolves within a few days. Recovery generally depends on the health of your immune system. 

With Norovirus, it's critical to replace lost fluids to prevent dehydration. Oral rehydration solutions may be used. If you're not able to drink enough fluids to prevent dehydration, you might need to receive fluids through a vein (intravenous).  If you suspect you or someone you're caring for has signs of dehydration, contact a health care provider.  They might recommend over-the-counter anti-diarrheal medication and medication to reduce nausea, or advice seeking additional medical care.

What are self care tips for Norovirus?

Stay hydrated:

• If your family includes young children, contact their pediatrician for specific self care measures. 
• Adults can drink sports drinks, broths or oral rehydration solutions.
• Avoid soft drinks and fruit juices that contain a lot of sugar can actually worsen diarrhea. 
• Avoid beverages with caffeine and alcohol.

Ease back into eating:

• Try to eat small amounts of food frequently if you experience nausea. 
• Gradually begin to eat bland, easy-to-digest foods, such as soda crackers, toast, gelatin, bananas, applesauce, rice and chicken.
• Stop eating if your nausea returns.
• Avoid milk and dairy products, caffeine, alcohol, nicotine, and fatty or highly seasoned foods for a few days.

Stay home and rest:

• Get plenty of sleep and rest
• To prevent further spread of this highly contagious illness, avoid contact with others as much as possible during illness and for several days after recovery.
• Wash your hands and disinfect surfaces and objects.
• Do not prepare food for others until your symptoms are gone.

Reach out to your care provider with questions and concerns:

• Your health care provider can give care considerations for your specific needs.
• Your health care provider can also help identify when and if self care preventions aren't enough, and you should seek out additional medical attention.

Sources:

Centers for Disease Control and Prevention 

Mayo Clinic