Gastroenteritis means inflammation of the stomach and small and large intestines. Viral gastroenteritis is an infection caused by a variety of viruses that results in vomiting or diarrhea. It is often called the "stomach flu," although it is not caused by the influenza viruses.

Causes

Many different viruses can cause gastroenteritis, including rotaviruses, noroviruses, adenoviruses,type 40 or 41, sapoviruses, and astroviruses. Viral gastroenteritis is not caused by bacteria (such as Salmonella or Escherichia coli) or parasites (such as Giardia), or by medications or other medical conditions, although the symptoms may be similar. Your doctor can determine if the diarrhea is caused by a virus or by something else.

Risk Factors

Food may be contaminated by food preparers or handlers who have viral gastroenteritis, especially if they do not wash their hands regularly after using the bathroom. Shellfish may be contaminated by sewage, and persons who eat raw or undercooked shellfish harvested from contaminated waters may get diarrhea. Drinking water can also be contaminated by sewage and be a source of spread of these viruses.

Symptoms

The symptoms of viral gastroenteritis usually begin between 1-2 days after you’re exposed to the virus. The illness usually lasts 1-2 days, but it can rarely last for up to 10 days.

Symptoms may include:

• Watery diarrhea

• Nausea

• Vomiting

• Abdominal cramps

• Fever

• Muscle aches

• Headache

Vomiting and diarrhea can lead to dehydration (losing more water than you take in), especially in children.

Diagnosis

Your doctor will ask about your symptoms and medical history, and perform a physical exam. Your doctor may also order a stool culture. This test looks for bacteria in a stool sample, which would indicate a different type of illness.

Treatment

The most important of treating viral gastroenteritis in children and adults is to prevent severe loss of fluids (dehydration). This treatment should begin at home. Your physician may give you specific instructions about what kinds of fluid to give. CDC recommends that families with infants and young children keep a supply of oral rehydration solution (ORS) at home at all times and use the solution when diarrhea first occurs in the child. ORS is available at pharmacies without a prescription. Follow the written directions on the ORS package, and use clean or boiled water. Medications, including antibiotics (which have no effect on viruses) and other treatments, should be avoided unless specifically recommended by a physician.

Prevention

Currently there is a licensed rotavirus vaccine available that protects against severe diarrhea from rotavirus infection in infants and young children. Studies into a norovirus vaccine are underway. You can take several steps to prevent viral gastroenteritis:

• If possible, avoid contact with people who have the condition.

• Always wash your hands thoroughly. Use warm water and soap, rub vigorously, and rinse well.

• Help your children wash their hands thoroughly.

• Use bleach to disinfect contaminated surfaces in your home (toilet, sink faucet in bathroom).

• Don’t share personal items (toothbrush, towels, drinking glasses).

• Take special care when traveling to countries that are more likely to have contaminated food and water. Only drink bottled water, avoid ice cubes, and don’t eat raw foods, including vegetables.

RESOURCES:

American Academy of Family Physicians
http://www.aafp.org

Centers for Disease Control and Prevention
http://www.cdc.gov

Mayo Clinic
http://www.MayoClinic.com

CANADIAN RESOURCES:

BC Health Guide, British Columbia Ministry of Health
http://www.bchealthguide.org

The Office of the Provincial Health Officer, Alberta Government
http://www.health.gov.ab.ca

References:

Viral gastroenteritis. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/ncidod/dvrd/revb/gastro/faq.htm. Accessed August 21, 2005.

Viral gastroenteritis. Mayo Clinic website. Available at: http://www.mayoclinic.com/invoke.cfm?objectid=E31CB1FE-4C04-4B05-A67DF0EEF09823B7. Accessed August 21, 2005.

CDC