First it’s the chills. Then the fever and stomach cramps. The next thing you know you are in the full throes of a nasty norovirus, aptly named the cruise ship virus for its ability to rapidly spread through a population, norovirus is one of the most contagious viruses out there that you can experience.

Angela Theiss, MD, a pathology resident at the University of Vermont Medical Center, shares information on norovirus.

Listen to the interview at the link below, or read the transcript that follows.

Norovirus: What exactly is it?

Norovirus is a highly infectious virus that is the most common cause of diarrhea and vomiting in the US and globally. Eighty percent of the outbreaks occur from November through April in the United States.

Is there a reason it happens during that time?

The reason why is because people tend to be in closer quarters so kind of like the flu, just more people packed in to places together makes it spread easily.

During the winter season and also during the holidays as people are out there in businesses, shopping malls, restaurants, in those close quarters, it’s very easy for viruses to spread.

How does it spread?

Norovirus is highly contagious. Typically a lot of people will come down with it all at once. They call it the cruise ship virus because it is easily spread from person to person who live or work in facilities like hospitals, nursing homes, and daycare centers. It also spreads through outbreaks in restaurants if a food worker has norovirus and goes to work and prepares food.

Why is it so highly contagious?

Basically, it’s just the fact that all you need is a 18 viral particles ingested to make you sick. That means that the amount of viruses that would be on a pinhead is enough to make about a thousand people sick. It’s just highly contagious and it tends to stick around for a while. If somebody vomits or has diarrhea, those particles can spread. If they don’t wash their hands properly, you can get those on tables or doorknobs. We in the medical field call those fomites. If anyone just touches them and then touches their mouth, they can get sick with norovirus. Typically, norovirus can stay on things for about days to weeks.


What are the symptoms?

Typically people will come down with vomiting and diarrhea and nausea. That’s a common complaint. You can get some stomach pain and cramping and then some people can come down with fevers, chills, and body aches. Most people typically recover in one to three days.

We recommend that you stay at home and get rest and drink plenty of fluids. There is no treatment for norovirus. Basically you’re just waiting out the virus. If you start to feel severely dehydrated or you’re really ill, then you should go to your doctor. Most people just experience some nausea and vomiting and diarrhea and they should stay at home.

The other interesting thing about norovirus is that it’s contagious days after you’ve had the illness. You’ll recover. You’ll feel completely fine, but you can shed a lot of the virus through your saliva and through going to the bathroom. If you don’t wash your hands properly and you think you’re okay, you’re still shedding that virus and that’s why it’s also so contagious.

How do we prevent norovirus?

The most important thing is to properly wash your hands.

You can use alcohol-based hand sanitizers but they’re not as effective. It’s not going to kill all of the virus. Then you don’t want to prepare food for others at least two days after recovering from norovirus. You want to disinfect all fomites, so all surfaces properly. Norovirus is really resistant to certain disinfectant solutions, so what they recommend is, what we recommend is you want to use gloves to clean surfaces so you don’t catch norovirus. Then use bleach-based cleaners, and you can make your own. We recommend you use one cup of bleach per one gallon of water.

Any contaminated clothes, you’re going to want to wash those really well and just be careful not to shake the clothes because that will also spread the virus. Anything that is possibly contaminated with vomit or diarrhea should be cleaned so I would even recommend if there are hand towels in the bathroom or towels in the bathroom and somebody’s been sick with norovirus just make sure that you clean those in the laundry.

Are there tests for norovirus?

Typically, it’s based on symptoms. But if providers, clinicians want to know more like specifically why someone is having diarrhea or public health officials sometimes want to know if there’s an outbreak, you can do molecular testing to detect norovirus and you can use molecular testing to test contaminated food and water as well as stool. UVM Medical Center performs molecular testing on stool.


How does norovirus spread through water? Could I get it from a drinking glass at a restaurant?

You could get norovirus from a drinking glass and the scenario there is that you have someone that is sick with norovirus or had norovirus a day or two previously and is feeling better and they touched their mouth, which has the norovirus particles, and touched the water or touched a glass. If you go and pick up that glass or drink that water, you can get norovirus through that.

What are some other ways in which I might catch norovirus?

Interestingly norovirus, because it’s highly contagious, it just requires a few viral particles to make you sick. Viruses are very small and so anytime anyone has norovirus and sheds the virus, they can touch a doorknob, they can touch tables, they can cough and spread it through the air. Anytime anyone goes to the bathroom, they can spread it that way. You’re not really safe unless you’re washing your hands a lot.

How about vaccines?

Unfortunately not. I don’t think there’s even any research into developing a vaccine because there are several different strains of norovirus, and so it’s just really hard to pin down which vaccine to develop for it.


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