Outbreaks of norovirus, an extremely contagious stomach bug, can spread quickly.

“‘Tis the season for germs,” said Dr. Michelle Barron, UCHealth’s senior medical director of infection prevention and control.

Norovirus cases typically spike during times of the year when adults and kids spend time together in crowded settings: like during and after the holidays, whenever kids head back to school and frequently on cruise ships.

What is norovirus?

Norovirus is the most common culprit for stomach bugs, but just like flu viruses, there are many types of norovirus. And, unlike the flu, there’s no vaccine.

“It’s a very infectious virus that causes pretty severe diarrhea and vomiting for 24 to 36 hours. If anybody in your household gets it, it’s just so infectious that everyone around you is likely to get it,” Barron said.

Symptoms from food poisoning, in contrast, usually last just a couple of hours. It typically stems from bacteria that have developed in food, like mayonnaise dishes that need to remain cold and have sat out in the sun too long.

Norovirus, on the other hand, comes from a virus. If you or your family members have had it — and most of us have — you know the drill.

“The terrible thing about norovirus is that by the time you figure out what it is, often it’s too late. Everybody has been exposed, and everyone is dealing with it,” said Barron

If one member of your family gets sick with norovirus, others are likely to get it too unless you isolate the sick person, wash your hands obsessively with soap and water and clean your home thoroughly.

Barron has two words of advice when it comes to dealing with norovirus: “use bleach.”

Why is norovirus so contagious? And why do you need to use bleach to disinfect against norovirus?

Norovirus is an extremely crafty bug and each particle comes with its own protective shield of sorts to help it survive as long as possible.

“Alcohol can’t break the shield. A detergent like soap can most of the time,” said Barron. “Be really diligent with hand washing. Make sure you’re washing your hands really well with soap and water and that you’re cleaning surfaces with bleach. Also, be very conscious about food preparation.”

She said hand sanitizers, which contain alcohol, can be useful to protect people from other illnesses like COVID-19, colds and the flu. So, it’s fine to keep hand sanitizer handy.

But, if you, your children or your co-workers are dealing with stomach illnesses, you should stay home so you don’t spread the virus and wash your hands very frequently with good old soap and warm water.

What cleaning agents should I use to prevent norovirus?

Barron recommends cleaning surfaces as often as possible with bleach-based detergents, which can kill norovirus.

Unfortunately, people who are infected with norovirus sometimes don’t know they have it until they get sick. In the meantime, they can touch food or surfaces in schools like desks and notebooks. The virus stays alive on the surface, then when other people touch the same spot, the infection spreads.

“It only takes one or two particles of this virus to make you sick,” Barron said.

According to the CDC, each person with norovirus can shed billions of particles of the disease.

So, once you get norovirus, all you can do is let the virus run its course and try to protect people around you from getting sick.

“In terms of what to do to treat it, the No. 1 thing is to stay home. There’s no treatment. You have to let it run its course,” Barron said.

Barron said norovirus is common when people are gathering in close quarters and are eating together.

She encourages hosts to be sure to use utensils to serve food so people don’t accidentally spread illnesses with their hands.

Norovirus 101:

Symptoms:

• Nausea.
• Vomiting.
• Diarrhea.
• Dizziness and lack of urination can be signs of severe dehydration.

Treatment:

• Consume plenty of fluids.
• Try to eat bland foods like crackers.

When you need to see a provider:

• If a baby or child becomes lethargic, has dry diapers and can’t consume any liquids, call your provider.
• Most older children and adults don’t need to see a provider for norovirus.
• If vomiting and diarrhea last longer than 36 hours or if people can’t hold down any liquids and stop urinating, they may need fluids in a hospital.

Prevention

• Wash hands frequently with soap and warm or hot water.
• Use detergents with bleach to clean and disinfect surfaces.