Health & Fitness

What is norovirus and how do you treat it? What to know about the ‘cruise ship virus’

Norovirus is a very contagious virus that often causes diarrhea and vomiting. Some people call it the “cruise ship virus.”
Norovirus is a very contagious virus that often causes diarrhea and vomiting. Some people call it the “cruise ship virus.”

Summer travel has returned and people are flocking to cruises again, with more than 31.5 million passengers expected to sail in 2023.

But sometimes people get sick while onboard.

Upset stomach or nausea? It could be sea sickness. Food poisoning. Or maybe it’s norovirus, a contagious virus that often keeps you at the toilet for several days. Some people know it as the “cruise ship virus” because it’s often the cause of over 90% of diarrhea outbreaks on cruise ships, according to the Centers for Disease Control and Prevention.

So far, cruise lines have reported 13 separate norovirus outbreaks to the CDC through the six months ending in June. It’s the most number of reported norovirus outbreaks on cruise ships since 2012, when there were 16.

What is norovirus? And how do you treat it?

Here’s what to know:

What is norovirus?

Sometimes known as the “stomach flu” or “stomach bug,” noroviruses are a very contagious virus that often causes vomiting, diarrhea, nausea and stomach pain. However, the virus is not related to the flu, which is caused by influenza.

How common is it?

Norovirus is the “leading cause of vomiting and diarrhea and food-borne illness in the United States,” with more than 2,500 norovirus outbreaks reported every year, according to the CDC.

The federal health agency says that the virus, on average, causes 19 to 21 million illnesses in the U.S. each year. While most people recover, the virus does cause about 900 deaths a year, mostly in adults 65 and older.

While the virus has garnered the nickname “cruise ship virus,” in reality, norovirus outbreaks on cruise ships account for only 1% of all reported norovirus outbreaks, the CDC says. In fact, acute gastrointestinal illness is fairly uncommon on cruise ships, the agency says.

How does norovirus spread?

Norovirus spreads easily and can make anyone ill, with symptoms usually lasting one to three days. The virus most often spreads in closed and crowded environments, such as hospitals, nursing homes, child care centers, school and cruise ships, according to the Mayo Clinic.

You can get norovirus in a variety of ways, such as by eating or drinking contaminated food and drinks, touching an infected surface and then touching your mouth or having direct contact with someone ill from the virus, according to the CDC.

How is it treated?

While there is no specific treatment to treat the illness, the CDC recommends drinking lots of water or other drinks, like sports drinks, that don’t have caffeine or alcohol to help avoid dehydration.

The best way to reduce your risk of falling ill? Wash your hands often with soap and water. And while you might still have a closet full of hand sanitizer from the COVID days, keep in mind that hand sanitizer doesn’t work well against norovirus.

Michelle Marchante
Miami Herald
Michelle Marchante covers the pulse of healthcare in South Florida and also the City of Coral Gables. Before that, she covered the COVID-19 pandemic, hurricanes, crime, education, entertainment and other topics in South Florida for the Herald as a breaking news reporter. She recently won first place in the health reporting category in the 2025 Sunshine State Awards for her coverage of Steward Health’s bankruptcy. An investigative series about the abrupt closure of a Miami heart transplant program led Michelle and her colleagues to be recognized as finalists in two 2024 Florida Sunshine State Award categories. She also won second place in the 73rd annual Green Eyeshade Awards for her consumer-focused healthcare stories and was part of the team of reporters who won a 2022 Pulitzer Prize for the Miami Herald’s breaking news coverage of the Surfside building collapse. Michelle graduated with honors from Florida International University and was a 2025 National Press Foundation Covering Workplace Mental Health fellow and a 2020-2021 Poynter-Koch Media & Journalism fellow.  Support my work with a digital subscription
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