Norovirus outbreaks on cruise ships have surged for the first time in more than a decade, with experts attributing the increase to relaxed travel restrictions and a rise in cruise passengers post-Covid pandemic.
Since the beginning of this year, there have been 13 norovirus outbreaks on cruise ships in the United States, marking the highest number since 2012 and exceeding the total for all of 2022.
One of the most recent outbreaks occurred in June on a Viking Cruises ship from Iceland that docked in New York, affecting 110 passengers and eight crew members.
Norovirus, commonly referred to as a “stomach bug,” is highly contagious and is the leading cause of nausea, diarrhea, stomach pain, and vomiting in the U.S., according to the Centers for Disease Control and Prevention (CDC).
Cruise ships are required to report cases of gastrointestinal illness to the CDC before arriving from a foreign port or when 2% of the crew and passengers are affected.
Dr. William Schaffner, an infectious diseases expert at Vanderbilt University, explained to KCRA Sacramento that norovirus spreads in crowded environments where airborne particles can easily transmit, making cruise ships particularly susceptible to outbreaks.
Annually, between 19 million and 21 million Americans are infected with norovirus, as reported by the CDC.
According to CDC data, 1,939 people have been infected with norovirus while aboard cruise ships this year. Outbreaks have occurred on cruise lines such as Celebrity Cruises, Viking Cruises, Princess Cruises, Royal Caribbean International, and P&O Cruises.
Norovirus is typically transmitted through ingestion of fecal matter particles, contaminated food, or contact with contaminated surfaces or infected individuals.
The virus is most contagious when symptoms are present and in the initial days after symptom relief. Symptoms include vomiting, nausea, diarrhea, stomach pain, muscle aches, low-grade fever, and headache, usually appearing within one to two days of exposure.
Despite previous declines in norovirus cases aboard cruise ships between 2006 and 2019, the CDC’s travel health notice during the Covid pandemic led to no reported outbreaks in 2020 and 2021.
However, the agency lifted the health notice in March 2022, advising against cruising without a booster shot despite the return to normalcy in 2019.
To minimize the risk of contracting norovirus while at sea, it is recommended that passengers increase their handwashing frequency, stay hydrated especially in hot weather, and avoid consuming ice, uncooked vegetables, and fruit with edible skin.
