Noroviruses

Noroviruses are significant causes of sporadic and epidemic gastrointestinal disease in the United States. (Read about "Digestive System") The Centers for Disease Control and Prevention (CDC) say over 180,000 cases occur annually. Noroviruses include Norwalk virus, Norwalk-like viruses and caliciviruses.

Noroviruses cause gastroenteritis, an inflammation of the gastrointestinal tract. (Read about "Gastroenteritis") The acute gastrointestinal illness, which can resolve within two days, results in symptoms that can include:

• vomiting
• diarrhea (Read about "Diarrhea")
• nausea
• abdominal cramps
• headache
• low-grade fever

Like all viral infections, noroviruses are not affected by treatment with antibiotics. (Read about "Antibiotics") However, as with any illness causing diarrhea and vomiting, a big concern with norovirus infection is dehydration. (Read about "Dehydration") Dehydration is especially problematic for children and seniors. It happens if the body loses more fluids and salts (electrolytes) than it takes in. Signs of dehydration include a decrease in urine production (Read about "The Urinary System"), extreme thirst, dry mouth and unusual drowsiness. Severe dehydration is a medical emergency and requires immediate care. CDC says special oral rehydration fluids can be purchased at drugstores, and can be used according to the package directions. You should ask your pediatrician what's best in your child's case. If you have any concerns about dehydration, contact your doctor at once. It's also important to call your doctor if there is fever or prolonged vomiting.

Noroviruses are very contagious and can spread easily from person to person. Both stool and vomit are infectious. Particular care should be taken with young children in diapers who may have diarrhea. Unlike many foodborne pathogens, CDC says it is believed that noroviruses spread primarily from one infected person to another. Infected kitchen workers can contaminate a salad or sandwich as they prepare it, if they have the virus on their hands. Infected workers have contaminated shellfish, especially oysters, during harvesting or preparation.

If you're concerned about noroviruses, it's a good idea to develop (and help children develop) habits that can reduce the risk of such infections. The following are suggestions from CDC and the International Food Information Council:

• Wash hands carefully and often. Adults should wash their hands after using the toilet, helping a child use the toilet, diapering a child and before preparing, serving or eating food. Children should wash their hands after using the toilet, after having their diapers changed (an adult should wash infant's or small child's hands) and before eating snacks or meals.
• Disinfect toys, bathrooms and food preparation surfaces frequently, especially if a sick child has been in the home.
• Use diapers with waterproof outer covers that can contain liquid stool or urine or use plastic pants and make sure that children wear clothes over diapers.
• Wash fruits and vegetables thoroughly before eating. (Read about "Food Safety")

Although you can't guarantee you or your family will never get an infection such as a norovirus infection, you can at least help reduce your risk.

Related Information:

    Microorganisms

    Food Safety