Digestive system
Digestive system
Digestive system organs
Digestive system organs

Viral gastroenteritis

Definition:
Viral gastroenteritis is an inflammation of the stomach and intestines caused by a viral infection.

Alternative Names:
Rotavirus infection; Norwalk virus; Gastroenteritis - viral

Causes, incidence, and risk factors:
Viruses cause 30 to 40% of cases of infectious diarrhea in the U.S. and viral gastroenteritis is the second most common illness, after upper respiratory infections.

Many types of viruses can cause gastroenteritis but the most common are Rotavirus and Norwalk virus. Rotavirus is the leading cause of gastroenteritis in children and can also occur in adults exposed to children with the virus. Norwalk virus causes group-related or institutional diarrhea with peak frequency during the winter. Norwalk-like viruses are common in school-age children.

These viruses are often found in contaminated food or drinking water. The viruses cause about 40% of group-related diarrheal illnesses. They affect older children and adults and are more frequent during the winter months. Symptoms appear within 4 to 48 hours after exposure to the contaminated food or water. The viruses are usually spread by the fecal-oral route.

Rotavirus causes severe gastroenteritis in infants and young children. Severe dehydration and death can occur in the young age group. It is responsible for up to 50% of the hospitalizations of children with diarrhea. Outbreaks may also occur in geriatric settings such as nursing homes. Usually, by the age of 3, most children have acquired an antibody to the virus.

Gastroenteritis affects the young, the elderly, and immunosuppressed people most severely.
Symptoms:
Additional symptoms that may be associated with this disease:
Signs and tests:
Stool assays for the viruses can identify the specific agent. A stool culture may rule out bacterial causes of the illness.
Treatment:
The objective of treatment is to replace fluids and electrolytes (salt and minerals) lost by diarrhea. Antibiotic therapy is not effective in viral illness. Antidiarrheal medications are generally not given, as they may prolong the infectious process. Self-care measures to avoid dehydration include drinking electrolyte solutions (available over-the-counter) to replace fluids lost by diarrhea.

People with diarrhea who are unable to take fluids by mouth because of nausea may need intravenous fluids, especially in small children.

People taking diuretics need to be cautious with diarrhea, and may need to stop taking the diuretic during the acute episode. (Always consult with the health care provider before stopping a prescribed medication!)

Do not give anti-diarrheal medications to children unless directed to do so by a health care provider. Since the risk of dehydration is greater in infants and young children, parents should closely monitor the number of wet diapers changed per day when the child is sick. Electrolyte and fluid replacement solutions for children are available in food and drug stores. Jell-O water, soda and plain water do not replace electrolytes the child needs when dehydrated from vomiting or diarrhea. Children with diarrhea often benefit from dietary modifications until the diarrhea subsides.
Expectations (prognosis):
Most infections will resolve spontaneously. Children may become severely ill from dehydration caused by diarrhea.
Complications:
Dehydration is the main complication but very rare severe reactions can occur.
Calling your health care provider:
Call your health care provider if unable to keep fluids down and symptoms of dehydration occur, including low urine output, faintness or dizziness, dry mouth, sunken appearance to the eyes, sunken fontanelle (soft spot on an infant's head), and confusion.

Also call if diarrhea persists for more than several days or if blood is noted in the stool.
Prevention:
Most infectious organisms are transmitted on unwashed hands. Prevention is best accomplished through proper food handling, and hand washing after using the toilet and whenever the hands are soiled.

Review Date: 3/3/2002
Reviewed By: Alan Greene, M.D., F.A.A.P., Chief Medical Officer, A.D.A.M.; Clinical Assistant Professor, Department of Pediatrics, Stanford University School of Medicine; Attending Physician, Packard Children's Hospital at Stanford (3/3/2002). Previously reviewed by David Loren, M.D., Division of Gastroenterology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network (5/25/2001).
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