Norovirus: Symptoms, causes and treatment

You’re feeling on top of the world one minute and then, mere hours later, you’re in bed, holding on for dear life. Or so it may feel. Few things can bring you down like norovirus. It comes on fast and often leaves little time to get home to the comfort of your couch or the safety of your bathroom before the worst of it strikes.

If you’ve ever experienced norovirus, you’ve probably asked some or all of these questions: How long will it last? How do I feel better? And could you bring me some ginger ale and saltines, please?

We’ll get to the bottom of this bothersome bug as we discuss where norovirus comes from, what symptoms to look out for and how to treat it. We’ll also tell you the most important thing about this nasty microbe: how to avoid it.

What is norovirus exactly?

Norovirus is an extremely contagious virus that is the leading cause of gastroenteritis, which is a general term for inflammation of the gastrointestinal tract and intestines.

Norovirus can occur at any time during the year, but it’s sometimes known as “the winter vomiting bug” since it can be common during cold and flu season. For its proper name, we can thank Norwalk, Ohio, where an outbreak in 1968 put the virus on the map. It was originally called the “Norfolk agent”, but over the years it’s become simply known as norovirus.

Symptoms of norovirus

Norovirus symptoms typically begin 1-2 days after ingesting the virus, but some people may notice symptoms as soon as 12 hours after exposure.

The most common symptoms of norovirus include:

• Vomiting
• Diarrhea
• Nausea
• Stomach pain

Less common norovirus symptoms include:

• Slight fever
• Achy limbs
• Headache

Norovirus symptoms vs. food poisoning

It can be hard to tell the difference between norovirus symptoms and symptoms of other types of food poisoning. But the best clue is how soon symptoms begin after you’ve been exposed, and how long they last.

Generally, the onset of other types of food poisoning happens much more quickly and runs its course faster too. Many people see symptom relief in hours, rather than days.

Norovirus symptoms vs. flu symptoms

Generally speaking, the most common norovirus symptoms and influenza symptoms are very different. But there may be some similarities for some people.

Symptoms for both illnesses can come on very fast and both can cause body aches and headache. But vomiting and diarrhea are the hallmarks of norovirus. These usually don’t occur with the flu, although sometimes children with the flu may experience them.

Also, the length of the illness is very different. Typically, flu symptoms can last 5-7 days, sometimes even longer. As we mentioned above, norovirus symptoms typically pass within about 48 hours. Plus, the flu will have you coughing with tiredness, weakness and some congestion that can last weeks. These symptoms are not present for norovirus.

Who is most at risk for severe norovirus symptoms?

Norovirus is an equal opportunity virus – it will infect anyone. But not everyone can bounce back as easily as your average healthy adult. Dehydration is the biggest threat to children, people with diabetes and the elderly. When left unchecked, dehydration can cause serious complications. Symptoms of dehydration to look out for include:

• Crying without tears (babies and toddlers)
• Sunken eyes
• Dark urine
• Lightheadedness
• Fatigue

Causes of norovirus and how it spreads

Norovirus is spread from person to person, but how does norovirus spread exactly? Noroviruses are found in the stool (poop) or vomit of infected people. So, the bug is most often spread to surfaces and foods by the hands of infected people who didn’t wash their hands adequately after going to the bathroom.

That means you can become infected with norovirus by:

• Eating or drinking foods that have been contaminated by the virus.
• Eating uncooked shellfish from contaminated waters.
• Touching contaminated surfaces or objects, and then touching your mouth or eating without thoroughly washing your hands first.

Is norovirus an airborne illness?

Technically, no. As we mentioned earlier, norovirus is most often transferred to foods, water or surfaces by the hands of an infected person who hadn’t washed their hands well enough. That said, it can also be caused by tiny particles from vomit spray that land on surfaces or enter a person’s mouth.

Technically, there isn’t such a thing as the “stomach flu”, but it’s become a general term used to describe tummy troubles such as diarrhea, vomiting, stomach cramps and nausea. And it’s true that symptoms like these are often caused by a norovirus.

But calling it a “flu” is incorrect. Flu is short for influenza, which is a respiratory illness caused by an entirely different virus. Influenza rarely causes vomiting and diarrhea, which we’ll talk about more below.

Is there a norovirus vaccine?

Unlike the flu, there’s no norovirus vaccine. And it can’t be treated with antibiotics because it’s a virus. There is comfort, however, in knowing you’re not going to get it again for a while. If you’ve had norovirus, your body has built up immunity to that strain. You’re in the clear, at least for another year. As with colds and the flu, norovirus adapts and usually changes from year to year. When that happens, you’re unfortunately no longer immune to it.

Can we predict how bad norovirus outbreaks will be each year?

There’s no way of knowing if any given year will be particularly bad for norovirus. The best precaution is to use commonsense health and hygiene practices. Keep those hands washed, get enough sleep and drink plenty of water.

How long does norovirus last?

It may not feel like it when you first have it, but norovirus won’t make you sick forever. The only good thing to be said about it is that it goes by quickly. Symptoms come on pretty fast, but they leave just as swiftly. Norovirus symptoms last an average of 48 hours, so take it as easy as possible and ride out the norovirus, knowing it won’t last much longer.

The best treatment options for norovirus

Treat norovirus the same way you’d treat any stomach bug. Be very kind to yourself and try to do the following:

• Drink lots of liquids – While you may not want to drink anything, it’s important to stay as hydrated as possible if you’re vomiting or having diarrhea. Sports drinks and other electrolyte replacements work great.
• Stay home – If you are still experiencing diarrhea and vomiting, stay home until those symptoms pass. Also consider isolating from others in your household if possible. For example, use a separate bathroom to help limit the spread. This will not only help you rest and feel more comfortable, but also reduce the risk of you spreading the illness to others.
• In fact, you can still transmit the virus days after it’s run its course, so be careful when returning to work or school.
• Reintroduce food slowly – Once your symptoms begin to lessen, a great way to start reintroducing food is using the BRAT diet (bananas, rice, applesauce and toast) which is easy on your stomach.

If you’re caring for someone with norovirus, be very careful to disinfect their surroundings and wash your hands frequently. Keep a close eye on children with norovirus – they can become dehydrated more quickly than adults.

How to prevent norovirus

As they say, prevention is the best medicine. So, keep the following steps in mind to help you avoid norovirus.

1. Wash your hands frequently and adequately

The best way to prevent norovirus is a simple one: Regularly wash your hands using warm, soapy water for at least 20 seconds – especially after using the bathroom and before preparing food. Interestingly, hand sanitizer has been shown to be less effective for norovirus, so when there’s an option, always choose traditional hand washing.

2. Follow best practices for safe food handling and preparation

Since norovirus can also come from food contaminated with the virus, you should always practice safe food handling methods:

• Wash fruits and vegetables before preparing or eating
• Cook oysters, which are at risk for contamination from water, and other shellfish thoroughly
• Keep surfaces clean and disinfected
• Avoid cross contamination
• Don’t touch your face while handing food
• If there’s a chance food has been in contact with norovirus, throw it out
• Do not cook or serve food if you’re sick

3. Disinfect bathrooms and surfaces regularly

One of the reasons norovirus is so contagious is that it’s hard to kill. The virus can survive on surfaces for up to a month. It’s also less susceptible to heat than other viruses. But the norovirus has its weak spot – bleach. Bleach kills norovirus.

When cleaning and disinfecting your home of norovirus, it’s important to take precautions. The following tips are recommended:

• Use rubber gloves, though it may seem like overkill – Norovirus loves to travel from hand to mouth, so use rubber or disposable gloves when you’re in any area that’s been exposed to norovirus.
• Use bleach or an EPA-approved disinfecting agent – Bleach should be used at the rate of 5-25 tablespoons per gallon of water.
• Wash dishes well – Norovirus can survive in conditions as hot as 145 degrees Fahrenheit. It tolerates higher temperatures than other viruses, so you’ll need to turn up the heat on your cleaning. For many, this will be as easy as setting the dishwasher to “sanitize”, which heats at 150 degrees Fahrenheit.
• Wash and sanitize laundry – Use the longest, hottest cycle for both washing and drying. Your washing machine and dryer heat up to the magic number of 150 degrees Fahrenheit, so norovirus won’t make it through the wash.
• When in doubt, wash your hands – Again, we cannot stress enough how important proper, regular handwashing is to avoiding norovirus and other illnesses.

4. Know the norovirus hotspots

Because of how quickly norovirus spreads and how tenacious the virus is, some places are more at risk than others. Places that are likely to be hit the hardest include:

• Hospitals/care facilities
• Camps
• Restaurants
• Schools
• Cruise ships
• Airplanes

Norovirus on vacation

Part of the fun of traveling is learning new cultures and trying new cuisines. You can have your baklava and eat it, too, if you’re careful about norovirus. Your chances of getting norovirus increase when traveling thanks to the confined spaces you’re often traveling in (think: cruise ships and airplanes).

Exposure to different foods and cooking methods may also cause norovirus. Stay safe by following these tips:

• Don’t drink tap water – Make sure any water you drink is bottled. If you enjoy coffee or tea, make sure tap water comes to a rolling boil before preparing.
• Take it neat – Ice can contain norovirus, so order your drinks without.
• Bring your own soap – Soap dispensers aren’t a given in bathrooms around the world, and you can’t rely on hand sanitizer to do the job when it comes to norovirus.
• Try new foods but don’t take risks – Don’t eat raw or undercooked shellfish, and make sure fruits and veggies are washed.

The risk of getting a nasty stomach bug like norovirus shouldn’t keep you from going on that vacation or seeing the world. Exercise a little more caution, and you should be fine.

Remember, help is here if and when you need it

Norovirus, while unpleasant, will typically run its course within 48 hours. Take the self-care steps mentioned above, and if you need more advice, call your care provider’s nurse line. For example, HealthPartners patients and insurance plan members can call our CareLine at 800-551-0859 or 952-993-4665.