Topline
Norovirus cases aboard cruise ships have spiked for the first time in over 10 years, and experts believe more lenient travel restrictions and an increase in cruise passengers following the Covid pandemic are to blame.
Royal Caribbean International’s ‘Oasis of the Seas’ cruise ship is seen at Port Canaveral, Florida … [+]
Key Facts
There have been 13 norovirus outbreaks on cruise ships since the start of the year, the most outbreaks the U.S. has witnessed since 2012, and more than there were in all of 2022.
The most recent occurred in June on a Viking Cruises ship from Iceland that docked in New York, where 110 passengers and eight crew members fell ill.
Norovirus is a highly contagious virus often described as a “stomach bug,” the generic description of the leading cause of nausea, diarrhea, stomach pain and vomiting in the U.S., according to the Centers for Disease Control and Prevention.
Cruise ships are required to report gastrointestinal illness cases to the CDC before arriving from a foreign port, or when 2% of the crew and passengers have the illness.
Transmission typically occurs in crowded spaces where particles can float around the air, making cruise ships a “relatively easy” place for norovirus outbreaks to occur, William Schaffner, a professor of infectious diseases at Vanderbilt University, told KCRA Sacramento.
Norovirus infects between 19 million and 21 million Americans annually, the CDC reports.
Big Number
1,939. That’s how many people have been infected with the norovirus while aboard cruise ships this year, according to CDC data. The outbreaks happened on Celebrity Cruises, Viking Cruises, Princess Cruises, Royal Caribbean International and P&O Cruises.
Key Background
Norovirus is typically spread by ingesting small particles of fecal matter, eating contaminated food, touching contaminated objects or surfaces and then touching the mouth or eyes, or having direct contact with an infected person. An infected person is the most contagious when symptoms are present and within the first few days of feeling better. According to the Minnesota Department of Health, symptoms of norovirus infection include vomiting, nausea, diarrhea, stomach pain, muscle aches, low-grade fever and headache. These symptoms usually appear between one to two days after contracting the virus but can appear as early as 12 hours after exposure. Cases typically last between 24 and 48 hours, though the illness may be more severe in young children and older adults, according to the Arizona Department of Health Services. Severe cases usually involve dehydration due to loss fluid—death is rarely ever a result. To avoid getting norovirus while at sea, it’s recommended passengers thoroughly wash their hands more frequently than they typically would, stay hydrated especially on hot days and avoid eating ice, uncooked vegetables and fruit with edible skin.
Surprising Fact
According to the Cruise Lines International Association, cruise passenger volume is estimated to reach 106% of 2019 levels this year, with 31.5 million passengers expected to set sail.
Tangent
Norovirus cases aboard cruise ships were on a steady decline between 2006 and 2019, according to CDC data. When the Covid pandemic hit, the CDC made a travel health notice advising against cruise ship travel. Because of this, there were no norovirus outbreaks in 2020 and 2021. However, in March 2020 the agency dropped the health notice, though it strongly urged against cruising without a booster shot.
Further Reading
CDC Drops Covid-19 Health Notice For Cruising (Forbes)