Norovirus infection is a highly contagious medical condition that causes unexpected and severe vomiting and diarrhea. It is usually spread through contaminated food or water. The contamination is generally by fecal matter and occurs during food preparation. It can also be spread by close contact with an infected person. Norovirus symptoms are usually diarrhea, vomiting and pain in the abdomen. They typically start 24 or 48 hours after being exposed to the virus and last for one to three days. Usually, people recover without treatments. However, in some cases, especially children, older people or people with another medical condition, the diarrhea and vomiting can lead to dehydration, so medical help is required. Norovirus infection frequently appears in small and crowded environments such as schools, hospitals, nursing homes or cruising ships.



The symptoms of norovirus infection are:

  • Malaise
  • Sickness
  • Nausea
  • Vomiting
  • Diarrhea
  • Pain in the abdomen
  • Cramps
  • Low fever
  • Pain in the muscles



Norovirus infections are shed in the feces of infected humans and animals. They are highly contagious and hard to destroy as they are resistant to both hot and cold temperatures and most of the disinfectants. They can be transmitted by:

  • Drinking contaminated water
  • Eating contaminated food
  • Touching the mouth with the hand after previously touching contaminated object
  • Close contact with an infected person


Risk factors

A person is at greater risk of becoming infected if:

  • He/she has a weak immune system
  • He/she lives in small and crowded places such as nursing homes
  • He/she lives with a child that goes to preschool or a care center
  • He/she is in a place where food is not handled with sanitary procedures
  • He/she stays in hotels, resorts, goes cruising or any other form of traveleing that includes lot of people in small areas



Generaly, the norovirus infection disappears after three days and it is not dangerous. However, in some cases the virus can result in severe dehydration and malnutrition or even death. These more severe cases are common among children and older adults that have compromised immune systems.

*Signs of dehydration are: weakness, dizziness, dry mouth and throat and decreased urine output.



There isn’t a specific way of treating norovirus infections. The recovery process depends on the immune system of each person. Usually the virus disappears after a few days.

What is really important in treating this virus infection is replacing the lost fluids in the body. That can be done orally or intravenously.

Drinking soft drinks and fruit juices, drinks with lots of sugar, can worsen the diarrhea. It is better to drink oral hydration solutions, or sport drinks and broths.

Anti-diarrhea medications can be of some help as well.

Small meals and bland diet can help control the vomiting. It is good to eat: soups, yogurt, banana, broiled vegetables and starches and cereals such as potatoes, noodles, rice or crackers.



In order to prevent the spreading of the virus, a person should:

  • Wash the hands thoroughly
  • Wash fruits and vegetables carefully
  • Avoid contaminated food and water
  • Dispose vomit and fecal matter cautiously
  • Disinfect areas that have been contaminated
  • Avoid travelling if the symptoms are still present
  • Do not go at work especially if the job includes handling food

N.B. A person can be contagious up to three days even after the symptoms have disappeared.