About norovirus infection

What is norovirus infection?

A norovirus is a small virus that contains RNA and is surrounded by a protein coating. By sequencing the RNA, scientists have discovered that there are many different types of norovirus. Originally, strains were named based on the city in which they were first identified. Thus, one common strain used to be called Norwalk virus. Based on genetic typing, we now know that there are at least 25 different strains of norovirus that affect humans. The RNA genome in noroviruses easily mutates to produce new norovirus types.

Norovirus infection is the most common cause of gastroenteritis outbreaks in the U.S. Although some people call this the "stomach flu," norovirus is not related to the influenza virus. According to statistics from the CDC, there are 21 million cases of norovirus infection annually in the U.S., of which one-quarter are related to food-borne outbreaks. Outbreaks occur throughout the year but are more common in the winter months. There is no specific treatment for norovirus. Fortunately, the disease is self-limited and simple supportive measures are sufficient to care for most people unless they become dehydrated. Outbreaks can occur almost anywhere in the world. In 2012, a new strain named GII.4 Sydney was identified. Since the first outbreak, the virus was quickly detected in New Zealand, France, and the U.S. It has caused about half of the norovirus infections detected in 2012-2013 in the U.S. A new outbreak of norovirus occurred at Yellowstone National Park, causing illness in about 200 visitors and camp employees in June 2013.

What are the symptoms for norovirus infection?

Signs and symptoms of norovirus infection include:

Signs and symptoms usually begin 12 to 48 hours after first exposure to the virus and last one to three days. You may continue to shed virus in your feces for up to two weeks after recovery. Viral shedding may last several weeks to several months if you have an underlying health condition.

Some people with norovirus infection may show no signs or symptoms. However, they are still contagious and can spread the virus to others.

When to see a doctor

Seek medical attention if you develop Diarrhea that doesn't go away within several days. Also call your doctor if you experience severe Vomiting, bloody stools, Abdominal pain or Dehydration.

What are the causes for norovirus infection?

Noroviruses are highly contagious and are shed in the feces of infected humans and animals. Methods of transmission include:

  • Eating contaminated food
  • Drinking contaminated water
  • Touching your hand to your mouth after your hand has been in contact with a contaminated surface or object
  • Being in close contact with a person who has a norovirus infection

Noroviruses are difficult to wipe out because they can withstand hot and cold temperatures as well as most disinfectants.

What are the treatments for norovirus infection?

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

It's important to replace lost fluids. 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).

Your health care provider might recommend over-the-counter anti-diarrheal medication and medication to reduce nausea.

What are the risk factors for norovirus infection?

Risk factors for becoming infected with norovirus include:

  • Eating in a place where food is handled with unsanitary procedures
  • Attending preschool or a child care center
  • Living in close quarters, such as in nursing homes
  • Staying in hotels, resorts, cruise ships or other destinations with many people in close quarters
  • Having contact with someone who has norovirus infection

Is there a cure/medications for norovirus infection?

The name "norovirus" refers to a family of viruses that can cause violent vomiting and diarrhea. It is widespread and simple to propagate (contagious). It is contagious through contaminated surfaces, contaminated food, and infected persons. Although many refer to norovirus as "the stomach flu," it has nothing to do with the flu (influenza).

Even though it is not the flu, norovirus infection can cause severe diarrhea and vomiting that is sometimes referred to as the stomach flu. It is very contagious and can be passed on through contaminated surfaces, food, or other individuals.


There is no known cure for norovirus. However, you can take action to lessen symptoms while the infection progresses. These consist of:

  • Consuming a lot of liquids
  • Mild dehydration can be helped by protein shakes and other non-alcoholic beverages without caffeine
  • Having a lot of sleep
  • Consume dull food
  • Because antibiotics combat bacteria rather than viruses, they are ineffective in treating norovirus infections.

Severe dehydration,Fatigue,Dry mouth and throat,Can even lead to death
Vomiting,Diarrhea,Nausea,Stomach Pain,Headache

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