Is it norovirus? Or the flu? How to know (and what to do)

Norovirus virions
This transmission electron micrograph reveals norovirus virions, or virus particles.
Charles D. Humphrey | Centers for Disease Control and Prevention

Updated: Dec. 23, 2015, 6 a.m. | Posted: Dec. 23, 2014, 12:58 p.m.

Minnesota Department of Health officials say a strain of norovirus that's associated with 20 reported outbreaks since September has emerged.

Here's a look at what norovirus is, how to prevent it and what you should do if you become ill.

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What is norovirus?

Norovirus causes gastroenteritis, or inflammation of the stomach or intestines (or both). The Centers for Disease Control and Prevention says noroviruses are the most common cause of foodborne-disease outbreaks in the United States. Most outbreaks in the United States occur between November and April.

How does it spread?

Very easily. Noroviruses are found in the stool or vomit of infected people, and transferred to food, water or surfaces handled by infected people who have not washed their hands adequately after using the bathroom.

Anyone who eats food or drinks liquid contaminated by an infected person will get sick. Touching contaminated surfaces or objects before touching your mouth, or sharing food or utensils with someone who is sick will also spread the illness.

Outbreaks can also occur from eating uncooked shellfish harvested from contaminated waters.

What are the symptoms?

The most common symptoms include:

• vomiting
• nausea
• diarrhea
• stomach cramps

Other symptoms:

• fever
• headache
• body aches

People typically become ill 24 to 48 hours after exposure to the virus, but most get better between one to three days.

Can I call it the stomach flu?

No. The flu is a respiratory illness caused by the influenza virus.

Flu symptoms include high fever, body aches, sneezing, runny nose and a sore throat.

What should I do if I have norovirus symptoms?

• Drink plenty of fluids to avoid dehydration.
• Wash your hands often with soap.
• Avoid preparing food for others while you have symptoms and for at least three days after you recover.

How can I prevent norovirus?

Take many of the same precautions above, such as washing your hands often (before handling food or ice, after using the bathroom, before eating, etc.).

You should also:

• Clean and disinfect contaminated surfaces
• Wash fruits and vegetables and cook seafood thoroughly
• Throw out any food that might be contaminated with norovirus