The highly contagious norovirus – popularly known as “stomach flu” or the “winter vomiting bug” – is now surging through the U.S.. The number of outbreaks is up significantly over previous years, possibly due in part to a new strain of the virus. Outbreaks can occur after direct contact with someone who is infected. Food and household surfaces can also become contaminated.

William Schaffner, a professor of preventive medicine and infectious diseases at the Vanderbilt University School of Medicine, discusses the symptoms of norovirus, how best to treat it, and the populations most vulnerable to this illness.

The Conversation has collaborated with SciLine to bring you highlights from the discussion that have been edited for brevity and clarity.

What are the symptoms of a norovirus infection?

William Schaffner: Norovirus is an intestinal virus that can make you very, very sick. It is indelicately called winter vomiting disease, and it begins suddenly, often with an explosive vomit that then repeats itself.

Norovirus can cause abdominal pain and diarrhea at the same time, along with a fever. It will probably make you feel miserable for two or three days – but then everybody pretty much recovers.

How should norovirus be treated?

William Schaffner: The major problem norovirus causes is dehydration from all that vomiting and diarrhea. So you have to stay hydrated. Do this with little sips of clear liquids, because if you take too much, it’ll come right back up. Sports drinks are very good.

Most people who get into trouble are either very young or older and more frail. They may have to go to the hospital to get rehydrated with an IV. When the occasional death occurs due to this dehydrating infection, it’s in those vulnerable populations.

Why does norovirus tend to surge during the winter?

William Schaffner: You can get it any time of the year, but there is a seasonal increase in the winter for reasons that scientists are not quite sure of. But people spend a lot of time indoors with each other in wintertime, so that makes it easier for the virus to get from one place to another. All that travel over the holidays, as well as family gatherings and parties, can spread the virus.

How can people protect themselves from the norovirus?

William Schaffner: The most important thing is good hand hygiene. Washing with soap and water works the best. Those hand hygiene gels and wipes – the hand sanitizers – that people tend to use aren’t as effective against norovirus, so just wash frequently with good old soap and water. And then, of course, avoid people who are sick.

Also, remember that the virus can survive on environmental surfaces, like counters, doorknobs and tables. You don’t want to pick up those viruses on your fingers. If you get a little bit of virus on your fingertips and then touch your lips, you can get an infection because it just takes a small dose of the virus to make you sick.

Who’s particularly vulnerable to norovirus?

William Schaffner: The people who are more susceptible to catching it are those living in semi-enclosed or enclosed populations. For example, people in nursing homes, schools and prisons – essentially any circumstance where people are together for a long period of time.

Another place where the virus can spread is cruise ships, which is why norovirus is also called the cruise ship virus. When people are confined on a ship for days and days, these outbreaks can run through most of the passengers.

Interestingly enough – and this has never been well explained – the crew is usually less affected.

But again, the most serious illness occurs in older, frail and immune-compromised people, or in the very young, where dehydration can be more serious.

Where’s the research on developing a norovirus vaccine?

William Schaffner: Norovirus has presented some scientific challenges. It’s actually rather difficult to grow in the laboratory, and so that has delayed the development of a vaccine. But researchers are working on it.

Are there other infectious diseases going around right now?

William Schaffner: Along with norovirus, respiratory viruses are still out there: influenza, COVID-19 and respiratory syncytial virus, or RSV. They’re all perking up at the same time. It looks as though we’re having a very brisk winter viral season.

Watch the full interview to hear more.

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William Schaffner, Professor of preventive medicine, health policy, infectious diseses, Vanderbilt University

This article is republished from The Conversation under a Creative Commons license. Read the original article.