Norovirus: Symptoms and prevention of gastric influenza
If norovirus cases rise sharply, these are symptoms that need to be aware of and measures that can be taken to prevent them.
- Gastrointestinal disease outbreaks on the 2025 cruise exceeded the 2024 total.
- Experts recommend washing your hands frequently with soap and water to prevent the spread of norovirus.
More than 70 people have been ill this month after the outbreak of the norovirus on the Royal Caribbean International ship. This case marks the 19th outbreak of gastrointestinal disease on a cruise that met the Centers for Disease Control and Prevention threshold for public notice in 2025, exceeding the 2025 total.
According to the CDC, 71 people, who, along with one crew, reported being ill during the voyage that began on September 19, reported 71 of the 1,874 passengers on the serenade of the Rhine seaship, were ill, according to the CDC. Their main symptoms were vomiting and diarrhea.
According to Crewmapper, the ship departed from San Diego for a cruise to Mexico, Costa Rica, the Panama Canal and Columbia. According to the CDC, the cruise line promoted cleaning and sanitation measures on board, quarantining isolated sick guests and employees.
The Royal Caribbean Group, the parent company of Cruise Line, issued an emailed statement to USA Today, saying, “The health and safety of our guests, crew and the communities we visit are our number one priority.” “We implement strict cleaning procedures to maintain an environment that supports the highest level of health and safety on our ship, many of which are well above public health guidelines.”
Are there any outbreaks on cruise ships?
The CDC has recorded 19 gastrointestinal outbreaks on cruises so far this year, of which 14 were caused by norovirus. The disease occurred in 2024 for 15 of the total outbreaks and 13 of the 14 in the previous year.
“The number of recent cruise ship outbreaks has been higher than before the pandemic, but it remains to be seen whether this represents a new trend,” the health agency told USA Today in late April. “However, CDC data shows that new dominant strains are currently associated with reports of norovirus outbreaks on land. Ships usually follow this high norovirus season’s pattern of outbreaks.”
A preliminary review found “potential overdependence on ship hand sanitizers,” which is less effective against the virus than soap and water, the agency said.
According to the CDC website, there were 2,675 norovirus outbreaks reported by 14 states participating in the Norostat Network between August 1st and July 31st, 2024. These have increased from 1,478 in the same period last season.
“The total number of reported outbreaks in the 2024-2025 seasonal year exceeds the range reported in the 2012-2020 and 2021-2024 seasonal year,” the website reads.
Sarah R. Michaels, an assistant professor at Celia Scott Weatherhead School of Public Health and Tropical Medicine at Tulane University, said norovirus can spread quickly on cruise ships, but most outbreaks haven’t happened there.
“They often happen within the community, and in many cases they don’t know what’s going on,” she told USA Today. “These areas where people are really in close contact, day care facilities, nursing homes, cruise ships, etc. are likely to be diagnosed, reported and attracted our attention.”
In fact, cruise ships make up only 1% of reported norovirus outbreaks.
How to protect yourself from norovirus
Michaels encouraged travelers to practice good hand hygiene.
“Washing your hands is a very important thing to do for a variety of infectious diseases, but especially for the norovirus, it’s really important to wash your hands not only after using the toilet, but before eating,” she said.
If symptoms began to develop, including vomiting, diarrhea, or nausea, Michaels recommended self-assessment to reduce spreads. For travelers who have not yet left, that may mean postponing their cruise or staying in the cabin if they are already on board. Passengers must also report symptoms to the ship’s medical staff.
CDC also recommends disinfecting and washing surfaces that may be contaminated.
“I don’t necessarily take that cruise or take that cruise for this reason,” Michaels said. “But take precautions and report your illness.”
Nathan Diller is a consumer travel journalist for Nashville-based USA Today. You can contact him at ndiller@usatoday.com.
