Federal health officials are investigating a suspected outbreak of norovirus aboard Holland America’s Veendam cruise ship that sickened several passengers and crew members during a Christmas week cruise to Mexico. If confirmed, the outbreak would be the third norovirus outbreak that officials with the U.S. Centers for Disease Control and Prevention (CDC) have investigated on cruise ships in December.
The CDC’s Vessel Sanitation Program, which was set up to assist the cruise ship industry with the prevention and control of norovirus and other gastrointestinal illnesses, reported that the Veendam outbreak sickened 57 passengers and 10 crew members, more than 3 percent of the ship’s 2,000 people on board.
Norovirus infections usually cause a potent gastrointestinal illness that includes nausea, vomiting, diarrhea, and cramps. Symptoms usually persist for 24 to 48 hours but usually subside quickly and most people fully recover. Infections can be dangerous for those in frail health or with a weak immune system, such as young children, the elderly, and patients with chronic illnesses or diseases.
Earlier in December, Vessel Sanitation Program officials investigated norovirus outbreaks aboard Princess Cruises’ Caribbean Princess, which sickened 176 passengers and crew, and Oceania Cruises Oceania Riviera, which sickened 86 people.
Norovirus can be brought aboard ship via contaminated food or water or by passengers who were infected with it ashore. The highly contagious virus can spread quickly once aboard ship, where close quarters, shared dining areas, and frequent passenger turnover facilitate its spread. Norovirus can also survive on surfaces and is resistant to many common disinfectants and cleaning agents.
The CDC reported that Holland America’s Veendam crew responded to the outbreak by stepping up cleaning and disinfection procedures onboard; collecting stool specimens from passengers and crew complaining of gastrointestinal illness for testing; making twice-daily reports to the Vessel Sanitation Program of illnesses; and consulting with the CDC to plan a staged voyage disembarkation to help mitigate the spread of norovirus among passengers.
Like nursing homes and camps, cruise ships are among the places that are required to report suspected outbreaks to CDC officials. Hotels, airplanes, malls, and other high-traffic areas are not required to report norovirus outbreaks, so the frequency of illness among the general population is thought to be much higher than reported cases indicate.