Cruise ship health is the protection of passengers and crew members from injury and disease during cruises. Although there are many facets to cruise ship health and safety, the major focus of attention is the prevention and control of outbreaks of gastrointestinal illness, especially from highly contagious noroviruses. The noroviruses cause gastroenteritis and similar problems of the stomach and intestines.
Cruise ships are isolated communities, with crowded accommodations and food, water, and sanitary facilities that are shared by thousands of passengers and crew—conditions that readily promote the spread of infectious disease. Passengers and crew can carry infectious organisms aboard ships, and cruise ships can inadvertently transport infected insects and rodents between ports. Thus, cruise ship health is a major global concern.
The cruise ship industry has undergone tremendous growth, and the size of the ships more than doubled over the first decade of the twenty-first century. It is a hugely profitable industry, even during times of economic recession, in part because cruise prices have remained relatively low. Most Carnival ships are registered in the Bahamas, Bermuda, or Panama, however. Holland America's ships are registered in the Netherlands, Royal Caribbean's in the Bahamas, and Celebrity's in Malta. Most cruise ship crews come from developing countries, especially India and the Philippines, and cruise ships are sometimes referred to as modern-day sweatshops. Crews routinely work long hours for many months straight for low pay, although wages are generally higher than workers could earn in their home countries, and their expenses are low. However, poor working conditions and crews that often speak little English have been cited as potential contributing factors to health and safety problems aboard cruise ships. There have been reports of ill crew members being forced to prepare passenger meals and of crews being ordered not to tell passengers about outbreaks of disease aboard the ships.
Cruise ships operate under the regulation of the International Maritime Organization, a division of the United Nations, and the International Convention on the Safety of Life at Sea, which was established following the death of 1,517 people onboard the Titanic in 1912. However, enforcement of regulations is the responsibility of the countries where the ships are registered. All ships calling at U.S. ports and carrying American citizens are subject to U.S. Coast Guard marine inspections. Other countries also carry out safety inspections, which may or may not be thorough. Still, since modern cruise ships can cost more than $1 billion, insurance agencies have very strict safety standards.
Illness from cruise ships usually start suddenly and are highly contagious. Most viruses contracted by cruise ship passengers and crews are intestinal illness caused by noroviruses. It is by far the most common type of disease on cruise ships. Disease outbreaks have received a great deal of media attention and can have a significant negative financial impact on cruise ship operators. Therefore, cruise lines follow specific regulations and guidelines for preventing onboard outbreaks of illness, with varying degrees of success.
In February 2012, three American cruise ships were struck with norovirus outbreaks in one weekend. Two Princess cruise ships had to undergo complete disinfection in their home port of Fort Lauderdale, Florida, after several hundred passengers and crew became ill. A third ship left the port of New Orleans several hours late after some 200 passengers became sick, requiring the ship to be disinfected. Despite widespread attention in the industry and media, however, outbreaks have continued. A Royal Caribbean curse made headlines in December 2017 when more than 500 people on two of their cruise ships fell ill. More than 11 incidents occurred in 2017, most of them caused by norovirus. Some of the illnesses were caused by foodborne pathogens, and respiratory infections also spread easily among cruise ship passengers.
Despite the frequency of contagious disease outbreaks on cruise ships, modern ships rarely fail their health inspections, and dozens of ships receive perfect inspection scores. When ships fail or fall below a perfect score, violations can include dirty ice machines, malfunctioning refrigerators and dishwashers, and flies in food preparation and storage areas.
Cruise ships often have state-of-the-art infirmaries, staffed with specialists in cruise ship medicine. However, cruise operators have limited responsibility for medical malpractice, and there have been reports of poor health care aboard the ships, including negligent death lawsuits. Cruise lines typically have no legal obligation for injured or ill passengers. In some events, the ship must drop off seriously ill passengers at the nearest island hospital, which might not be as safe and sanitary as expected and can be expensive.
Outbreaks of contagious disease and medical emergencies, such as heart attacks, are not the only health concerns aboard cruise ships. Passengers are often older and may come aboard with a range of health issues and susceptibilities. Passengers sometimes engage in unaccustomed strenuous physical activities that present a risk of injury. Others become seasick. Finally, there are reports that the average passenger gains 8 lb. (3.6 kg) during a one-week cruise, courtesy of the multiple dining rooms, endless buffets, and 24-hour room service.
There is always some risk of contracting a contagious disease on a cruise ship, since passengers and crew are exposed to large numbers of people in a new and confined environment. A gene called FUT2 makes some people more susceptible to norovirus infection. The elderly, infants, and people with compromised immune systems are more at risk for serious illness from contagions such as noroviruses.
Many more people are taking cruises, both because cruises eliminate some of the difficulties and frustrations of foreign travel and because cruises have become more affordable. According to the Cruise Lines International Association, the marketing group for the North American industry, more than 24.7 million people cruised in 2016, including millions of Americans.
The incidence of disease outbreaks and other health issues aboard cruise ships is not precisely known, although outbreaks are reported and tracked more quickly than on land. The Vessel Sanitation Program (VSP) of the U.S. Centers for Disease Control and Prevention (CDC) posts disease outbreaks on cruises that meet the following criteria:
Reports of norovirus outbreaks on cruise ships increased significantly after 2001, in part because more passengers traveled on many more ships. From 2008 through 2014, more than 74 million people sailed on cruise ships inspected by VSP, and fewer than 130,000 met criteria for acute gastroenteritis. When viewed with these numbers, the percentage of people sickened on cruise ships seems small and ranged from 3% in 2016 for several cruise lines to nearly 23% on one 2016 expedition.
The vast majority of disease outbreaks on cruise ships are attributable to noroviruses, but sometimes the cause of an outbreak cannot be identified. Occasionally there are simultaneous outbreaks of more than one disease. In addition to noroviruses, other causes of cruise ship outbreaks have included:
Some infections occurring on cruise ships spread through air. Often, disease outbreaks on cruise ships are traced to a single food handler or newly arrived passenger. Cruise ship buffets are particularly susceptible to contamination. However, person-to-person contact is the most common source of contagion on cruise ships. Poor cleaning of restrooms has been shown to contribute to cruise ship outbreaks. In addition to noroviruses, bacteria, and parasites, there have been hepatitis outbreaks on cruise ships, and reports of bedbugs are not uncommon.
Noroviruses are extremely contagious and can sicken hundreds of passengers and crew in a remarkably short time. Unlike other foodborne pathogens, noroviruses are spread primarily by infected people, especially food-service workers. In addition to direct contact with an infected person and contaminated food or water, the virus can be passed through contaminated surfaces, such as handrails or elevator buttons. A 2016 study looked at how norovirus is spread on cruises based on passenger behavior and surfaces or locations. The authors found that frequent disinfection of common surfaces such as restroom door handles, chairs, and hand rails can help prevent spread.
Noroviruses cause acute gastroenteritis—inflammation of the stomach and/or intestines, with diarrhea, nausea, and vomiting. Noroviruses can also cause stomach pain, abdominal cramps, fever, and headache. The illness generally lasts from one to three days. It can be extremely debilitating for the very young, the elderly, and anyone with a weakened immune system. Dehydration from diarrhea and vomiting in such individuals may be life-threatening.
There is no specific treatment for norovirus infection, other than fluids and possibly electrolyte solutions to prevent dehydration. If many passengers and crew become ill, the ships usually return to port for disinfection.
The VSP was established in 1975 to assist the cruise ship industry in implementing sanitation programs. Cruise ships that carry at least 13 passengers and call at both foreign and U.S. ports fall under VSP jurisdiction. The VSP conducts unannounced twice-yearly sanitation inspections of passenger ships docking at U.S. ports and grades the ships on a 100-point scale. The scores are published monthly, with a score of 86 required for passing. The inspections include tests of water quality, general cleanliness, food storage, and potential sources of contamination. The VSP also monitors, investigates, and responds to cruise ship outbreaks, trains cruise ship employees in public health practices, and conducts scheduled construction inspections.
The VSP website lists cruises in which more than 3% of passengers or crew became ill, as well as additional outbreak prevention and control strategies being implemented by the affected cruise line. When sailing from a foreign port, cruise ships under VSP jurisdiction must report the total number of cases of gastrointestinal illness seen by medical staff before arriving at a U.S. port. The VSP may advise cruise ships to do the following:
Although most cruise ship disease outbreaks do not cause serious or long-lasting illness, they can ruin a dream vacation. Rarely, vulnerable individuals can develop life-threatening illnesses.
The most important measure for maintaining cruise ship health is frequent and thorough hand washing, especially before eating, drinking, or smoking, and after touching one's face or using the toilet. Other preventive measures are:
Passengers should carry their medical summaries and ensure that cruise itineraries and excursions are suitable for their medical conditions. Passengers might want to buy insurance that covers unexpected medical expenses in foreign ports, as well as air evacuation.
Passengers of cruise ships also should have up-to-date vaccinations for flu, measles, chickenpox, and other common vaccines or illnesses, as well as recommended vaccines for the country or region through which they will travel. As of 2015, the CDC and the Bill and Melinda Gates Foundation were bringing together experts to research and develop a vaccine against norovirus that could be given to passengers before a cruise. However, norovirus is similar to the seasonal flu in that there are many different strains, and different ones circulate in different years, so once available, any vaccine might need to be updated annually.
See also Communicable diseases ; Disease outbreaks ; Noroviruses .
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National Institute of Allergy and Infectious Diseases, Office of Communications and Government Relations, 5601 Fishers Lane, MSC 9806, Bethesda, MD, 20892-9806, (301) 496-5717, Fax: (301) 402-3573, (866) 284-4107, email@example.com, http://www.niaid.nih.gov .
U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA, 30333, (800) CDC-INFO (232-4636), firstname.lastname@example.org, http://www.cdc.gov .
Margaret Alic, PhD
Revised by Teresa G. Odle, BA, ELS