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Viral Gastroenteritis

Viral Gastroenteritis

Viral gastroenteritis is an inflammation of the stomach and intestines caused by one of any number of viruses. Also known as the stomach flu, viral gastroenteritis can affect anyone throughout the world. This highly contagious illness spreads through close contact with people who are infected, or through contaminated food or water. It can easily spread in close quarters, such as childcare facilities, schools, nursing homes, and cruise ships.

Many different viruses can cause the illness, each with its own peak season. The most common viruses include:


This virus commonly affects infants and young children, who then spread the infection to other children and adults. It is usually spread orally, meaning the virus enters a person’s body through their mouth. Symptoms typically appear within two days of infection and include vomiting, loss of appetite, and watery diarrhea. According to the Centers for Disease Control and Prevention (CDC), this virus is most common between the months of December and June. (CDC, 2011)


This type of virus is highly contagious and can affect anyone at any age. It is spread through contaminated food, water, and surfaces, or by infected people. This type of virus is common in crowded spaces, such as nursing homes, daycares, and schools. Symptoms include nausea, diarrhea, fever, and body aches. Most norovirus outbreaks in the United States occur between November and April.

According to the National Center for Biotechnology Information (NCBI), viral gastroenteritis is the leading cause of severe diarrhea in adults and children. (NCBI, 2012) Children under the age of five and the elderly are at particular risk of severe diarrhea.

There are steps you can take to lower your chances of contracting the viruses that cause viral gastroenteritis. These include frequent hand washing and avoiding contaminated water and food products. A rotavirus vaccine was approved for infants in 2006; early vaccination is recommended to prevent severe rotavirus illnesses in infants and small children.

Most people make a full recovery in two or three days, with no lasting side effects.

Causes of Viral Gastroenteritis

Viral gastroenteritis is caused by a number of different viruses. People at higher risk are:

  • children under age five
  • older adults, especially if they live in nursing homes
  • children and adults with weakened immune systems

It is easy for this virus to spread among people in group situations, such as in schools, dormitories, hospitals, and cruise ships. Some of the ways the virus is transmitted include:

  • improper hand washing, especially by food handlers
  • water contaminated by sewage
  • consuming raw or undercooked shellfish from contaminated waters

Symptoms of Viral Gastroenteritis

Symptoms usually begin one or two days after infection and include:

Symptoms can last anywhere from one to 10 days.

Complications of Viral Gastroenteritis

The main complication of viral gastroenteritis is dehydration, which can be quite severe in babies and young children. Dehydration can be life-threatening. Call your doctor if you or your child has these symptoms:

How Viral Gastroenteritis Is Diagnosed

Most of the time, a physical exam is the basis for diagnosis, especially if the virus is spreading through your community. Your doctor may also order a stool sample to test for the type of virus or to find out if your illness is due to a parasitic or bacterial infection.

Treatment for Viral Gastroenteritis

The main focus of treatment is to prevent dehydration by drinking plenty of fluids. In severe cases, hospitalization and intravenous fluids are necessary.

The CDC recommends that over-the-counter oral rehydration solutions (OHS), such as Pedialyte, be kept in the homes of families with young children (CDC). OHS are specially made to be easy on a child’s stomach, and they contain a balanced mixture of water and salts to replenish essential fluids and electrolytes. These solutions are available at local pharmacies and don’t require a prescription. However, instructions should be followed carefully.

Antibiotics have no effect on viruses. Check with your physician before taking any over-the-counter medications.

If you have viral gastroenteritis, there are some self-care steps you can take.

  • Drink extra fluids with and between meals. If you have difficulty drinking, try very small amounts of water or suck on ice chips.
  • Avoid fruit juices, as these do not replace minerals and can actually increase diarrhea.
  • Children and adults can use sports drinks to replenish electrolytes. Younger children and infants should use products formulated for children, like oral rehydration solutions.
  • Eat food in small amounts and let your stomach recover.
  • Get lots of rest. You may feel tired or weak.
  • Check with your doctor before taking medications or giving them to children. Never give aspirin to children or teenagers with a viral illness. This can cause Reye’s syndrome, a potentially life-threatening condition.

Long-Term Outlook for Those with Viral Gastroenteritis

Viral gastroenteritis generally resolves without treatment within two or three days. Most people fully recover, with no lasting side effects.

Preventing Viral Gastroenteritis

Viral gastroenteritis is easily spread. There are some things you can do to lower your chances of contracting the virus or spreading it to others.

  • Wash your hands often, especially after using the bathroom and before food preparation. If necessary, use hand sanitizer until you can access soap and water.
  • If someone in your household is sick, do not share kitchen utensils, plates, or towels.
  • Do not eat raw or undercooked foods.
  • Wash fruits and vegetables thoroughly.
  • Take special precautions to avoid contaminated water and food when traveling. Avoid ice cubes and use bottled water whenever possible.
  • There are two vaccines for rotavirus. These are generally started when an infant is two months old. Ask your doctor if you should have your infant vaccinated.

Content licensed from:

Written by: Ann Pietrangelo
Medically reviewed on: Sep 17, 2012: George Krucik, MD, MBA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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