Norovirus Oubreaks on Cruise Ships: How to Avoid Getting Sick on Vacation

Fact checked by Nick Blackmer

• There have been 13 norovirus outbreaks on cruise ships in 2023.

• Experts note that the highly congested environment, as well as the fact that people have not been exposed to as many illnesses due to the COVID-19 pandemic, are likely the reason for the increased norovirus numbers.

• Experts recommend maintaining proper hygiene habits and contacting the ship’s medical facility as soon as you don’t feel well in order to avoid spreading illnesses while at sea.

Multiple cruise lines are experiencing norovirus outbreaks.

There have currently been 13 norovirus outbreaks on cruise ships in 2023. The most recent outbreak occurred on a Viking Cruises ship, which traveled from Iceland and docked in New York City. About 13% of its passengers and several crew members became ill with the virus while on board.

With more than 31 million passengers worldwide expected to set sail this year, experts told Health that these highly-congested environments—along with the fact that people have not been exposed to a normal amount of illnesses due to the pandemic—could be the reasons for the increased numbers.

“Loosening of restrictions after the COVID-19 pandemic makes us more susceptible to picking up viruses after several years in seclusion,” Sanjiv Shah, MD, MPH, an infectious disease specialist and chief medical officer for MetroPlusHealth, New York City’s public health insurance program, told Health.

“Children who have been able to avoid the virus during the pandemic are now being exposed to viruses that tend to peak during the school year,” he said. “While norovirus is higher this year, the numbers are not a big outlier compared to pre-pandemic levels.”

What Is Norovirus?

Norovirus is the most common cause of gastroenteritis and foodborne illness. Though people often call it the “stomach flu,” it has nothing to do with flu, Brian Labus, PhD, MPH, REHS, an expert in infectious diseases, told Health.

“You have to swallow the virus to get sick,” Labus, an assistant professor in the Department of Epidemiology and Biostatistics at the UNLV School of Public Health, said. “That can be through consuming contaminated food or touching a contaminated surface and then touching your mouth or not washing your hands before you eat.”

Norovirus, which causes inflammation of the stomach or intestines, typically causes diarrhea, vomiting, nausea, and stomach pain Bernadette Boden-Albala, DrPH, MPH, director and founding dean of the Program in Public Health at the University of California Irvine told Health. Other symptoms can include fever, headache, and body aches.

Typically, norovirus lasts for one to three days, though you can spread the illness for a few days after.

“Infected people spread the virus widely and make it difficult for public health officials to contain the virus,” Boden-Albala said.

Why the Number of Norovirus Outbreaks Increased

The exact cause for the increase in the number of norovirus cases is not clear, but the increasing demand for cruises could be one explanation for the rise in reported cases, said Labus.

During COVID, the options for cruises were limited, but now that restrictions have been lifted, more people are deciding to take that cruise they had been putting off.

People also are more likely to get sick now since pandemic restrictions have been lifted. For the past few years, people have not been exposed to as many common viruses and illnesses and now that exposure is rising, illnesses are bound to rise as well.

It also is possible the numbers for norovirus on cruise ships appear more alarming than they truly are.

On cruise ships, health officials are legally required to track any illnesses that occur, while this same reporting is not required on land. For this reason, the Centers for Disease Control and Prevention note that outbreaks are reported more frequently on sea than on land.

“The risk of getting norovirus each year is about 1 in 15 [but] a cruise passenger has about a 1 in 5,500 risk of getting norovirus,” Sally Andrews, vice president of strategic communications and public affairs for the Cruise Lines International Association told Health.

Related: What Is Human Metapneumovirus? CDC Reports Unusual Spike of Respiratory Virus

Environments Where Norovirus Spreads Quickly

According to Shah, norovirus spreads rapidly anywhere there are large groups of people, like school classrooms, family gatherings, and weddings.

Cruise ships in particular have many of the conditions that make people susceptible to norovirus—close quarters, enclosed spaces, communal dining, and high turnover of passengers.

“The virus is often associated with cruise travel simply because health officials are required to track illnesses on ships,” Shah said. “The CDC estimates only about 1% of annual U.S. norovirus cases happen on cruise ships. Rates are much higher in schools, nursing homes, hospitals, and restaurants, which collectively account for about 91% of cases.”

Minji Kang, MD, an assistant professor and infectious disease specialist in the Department of Internal Medicine at UT Southwestern Medical Center added that norovirus can also be brought onboard by contaminated food or water, or passengers who were infected while ashore.

Related: Sick Restaurant Workers Linked to 40% of Foodborne Illness Outbreaks, CDC Says

Yes, Cruise Ships Have Strategies to Prevent Outbreaks

Because norovirus outbreaks can flare up in the close quarters of a ship, the cruise industry has had norovirus prevention programs in place for nearly 20 years, Labus said. “They have the right chemicals needed to control it and the plans and training for how to use them appropriately.”

Cruise ships also have plans for how to deal with ill guests to ensure that they are not infecting other passengers, he said. “It’s important to let the ship’s medical staff know if you are sick so that they can protect the rest of the passengers.”

According to the American College of Emergency Physicians (ACEP), every cruise ship must have a place to isolate any passengers who have a contagious disease. This step helps them minimize the risk of spreading the disease to others.

What’s more, the CDC has established a rigorous Vessel Sanitation Program (VSP) to help prevent the overall spread of illnesses on cruise ships. Not only do they inspect a cruise ship’s medical center, but they also monitor their portable water systems, dining rooms, housekeeping procedures, heating, ventilation, air conditioning (HVAC) systems, and more.

If a cruise ship does not do well on its inspection—or gets an 85% or lower—it cannot set sail until it corrects the issues.

Staying Healthy While on a Cruise

While there have been 13 outbreaks of norovirus on cruise ships this year, Labus explained that not every cruise passenger is going to be exposed to the virus. Still, taking certain steps to prevent the likelihood of getting sick is never a bad idea.

“The most important measure to prevent the spread of norovirus is to wash your hands with soap and water for at least 20 seconds,” said Kang. “This should be done before eating and drinking, brushing one’s teeth, and after going to the bathroom, touching high-hand contact surfaces, and taking care of a sick person.”

She noted that hand sanitizers do not work well against norovirus and that they are not a substitute for handwashing.

For extra peace of mind, you can also research your cruise line prior to booking.

To see how your specific cruise line performed on its VSP inspections, you can visit the CDC website and search their portal. This site also lists any corrective actions taken to remedy any issues. You can even look for cruise lines that have scored a perfect 100.

If you do happen to get sick while on a cruise, Boden-Albala recommends that you follow CDC guidelines and report your illness to the ship’s medical facility as soon as possible. “[You also should] rest and drink plenty of water to rebuild your immunity system and prevent dehydration.”

Even though you may be tempted to conceal your illness, you would be doing a great disservice to the other passengers and the crew on the cruise by keeping it a secret.

“While staying in your cabin [for a day or two] may not make for the best vacation,” Shah said, “it’s important to take precautions to avoid infecting others.”

Related: CDC Stops Reporting COVID-19 Cases on Cruise Ships—Here's How You Can Still Stay Safe

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Read the original article on Health.