Viral gastroenteritis

Alternative names:

Norwalk virus; Rotavirus infection

Definition:

An inflammation of the stomach and intestines caused by a viral infection.

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 causes about 40% of group-related diarrheal illnesses. They affects older children and adults and is more frequent during the winter months. Symptoms appear within 4 to 48 hours after exposure to the contaminated food or water. The viruses is 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 antibody to the virus.

Gastroenteritis affects the young, the elderly, and immunosuppressed people most severely. The incidence is 2 out of 1,000 people.