You may have seen in the news last month that more than 500 people fell ill to norovirus on two separate cruise ships, bringing to 12 the number of major outbreaks of this nasty virus aboard ocean-liners in 2017, according to the Centers for Disease Control. That may lead you to think that norovirus is something you only risk on a cruise ship. But there’s actually a better chance you’ll be infected in restaurants, long-term care facilities like nursing homes and in other places where people gather and share bathrooms – day cares, schools, camps, and big events. Norovirus is also known as the “winter vomiting bug,” so it’s a good time to talk about reducing your risk.

What does norovirus do to us?

It’s not pleasant. Norovirus causes gastroenteritis, which is an inflammation of the stomach and intestines. That leads to stomach cramping, nausea, vomiting, and diarrhea. The virus is found in the vomit and stool of infected people. Other symptoms include stomach pain, fever, headache and body aches. It’s highly contagious – a very small amount of the virus can make you sick. It’s estimated that a person will get norovirus five times in their life.

Who is at risk?

Everyone is at risk, but the very young and old and those with weakened immune systems are more likely to get sick. Norovirus is the most common cause of gastroenteritis in the United States and while it can strike year-round, it’s more common during the winter. The CDC estimates that 19 to 21 million cases of acute gastroenteritis are caused by norovirus each year. Most people recover in about three days, but the virus causes up to about 70,000 hospitalizations and up to 800 deaths a year in the United States.

How does a person become infected?

People get norovirus from contaminated drinks and foods, including undercooked shellfish, such as oysters, and fresh produce, from stool or vomit from a sick person who didn’t wash their hands properly before touching food or serving utensils, by touching contaminated things like doorknobs and then putting fingers in mouths, swallowing contaminated recreational water, or by having direct contact with someone who is infected.

How long are people contagious?

They are most contagious from when they start to feel sick until at least three days after they recover. Some people are contagious for even longer. That’s why it’s so important to stay home when you feel sick and wait to visit people at highest risk for 48 to 72 hours after symptoms are over. Also, don’t prepare food for others while you are sick and for at least 48 hours after you recover.

How is norovirus disease treated?

There is no antiviral medicine for norovirus. Be sure to drink plenty of fluids to avoid dehydration, which can set in quickly. If you have symptoms of dehydration, such as increased thirst, dry mouth, small amount of urine, darker urine than normal, headache, and dizziness, contact your doctor.

So how can we protect ourselves?

There is no vaccine to prevent it. The best way to protect yourself is to wash your hands often, but especially after using the toilet or changing a diaper, and always before eating or preparing food. Other ways to reduce the risk of infection include thoroughly washing fruits and vegetables, and cooking oysters and other shellfish thoroughly before eating them. Potentially contaminated surfaces should be cleaned with a bleach-based cleaner or other disinfectant labelled as EPA-registered against norovirus. Any contaminated clothing or blankets also should be washed and dried.

A Closer Look at Your Health airs weekly Tuesday mornings at 6:50 a.m. on KBOI 670 AM in Boise; this is a transcript of the Jan. 16, 2018 program. 

Resources:

• cdc.gov/norovirus
• OSHA fact sheet on norovirus prevention for workplaces & employees