Noroviruses refer to a group of viruses. They cause inflammation of the stomach and intestines. It is called
or the stomach flu. In the US, they are the second leading cause of illness. Outbreaks have occurred in settings such as:
Any other location where the virus can spread quickly to a large group of people
This may require medical attention, especially in children, the elderly, and those with compromised immune systems
Prevent dehydration by drinking a lot of fluids, including water and juice
After exposure to the virus, symptoms often appear within 24-48 hours. You may feel ill as early as 12 hours. Symptoms often last about 24-60 hours.
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Diagnosis can be made based on a stool specimen. Often, your doctor can determine this illness without ordering any lab tests.
Currently, there are no treatments. Because gastroenteritis is caused by a virus, antibiotics cannot cure it. There are no antiviral medications or vaccines. The illness is often brief.
The only complication would be dehydration due to vomiting and diarrhea. In certain groups of people, this may require a hospital stay to replenish fluids.
Noroviruses can survive extreme heat and cold. The virus can also live in water with up to 10 parts per million of chlorine. This is much higher than what public water supplies have. There are ways, though, to limit exposure.
To help reduce your chance of getting noroviruses take the following steps:
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thoroughly after using the bathroom (or changing diapers). This is very important before handling food or eating. If you are caring for someone who is infected, make sure the person thoroughly washes his or her hands.
Wash fruits and vegetables. Steam oysters and clams.
Do not prepare food if you have symptoms. Wait three days after you have recovered before handling food again.
Throw away contaminated food.
If you are ill or caring for someone who is ill, immediately clean and disinfect contaminated surfaces using bleach cleaner. Remove and wash soiled linens. Use hot water and soap.
If you are sick, do not attend work. Staying home will prevent you from passing the virus to others.
If you work in a healthcare facility, isolate sick individuals to reduce the virus from spreading.
Norovirus in healthcare facilities fact sheet. National Center for Infectious Diseases: Respiratory and Enteric Viruses Branch. Centers for Disease Control and Prevention website. Available at:
. Accessed June 11, 2007.
The Norwalk virus family. In:
The Bad Bug Book: Foodborne Pathogenic Microorganisms and Natural Toxins Handbook
. US Food and Drug Administration; 1992. Center for Food Safety and Applied Nutrition website. Available at:
. Accessed June 11, 2007.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a