Norovirus

Member cruise lines of Cruise Lines International Association (CLIA) identify the safety and well-being of their passengers and crew as their highest priority. Many of CLIA’s member lines are part of the Centers for Disease Control and Prevention's (CDC) Vessel Sanitation Program (VSP) and proactively report communicable illnesses on board to the CDC. If increased incidents of norovirus occur, cruise lines take every precaution to contain the spread of this virus through aggressive sanitation measures and open communications with their guests before boarding and while on board the ship.

What is norovirus?
A common type of gastrointestinal virus called norovirus, sometimes referred to as the "stomach flu," is the second most prevalent illness in the general population behind the common cold. Symptoms include diarrhea, vomiting and/or stomach cramping. The illness itself is not life threatening and most symptoms last for 1-2 days. Norovirus can be transmitted from person to person through direct contact, eating or drinking foods and liquids infected with norovirus, or indirectly from transfer of the virus to surfaces that are then touched by another person. The number of cases can be amplified in areas of close living quarters such as dormitories, hospitals, nursing homes, schools and cruise ships.

Why does norovirus seem to affect cruise ships often?
CDC's Facts About Noroviruses on Cruise Ships.
While norovirus is very common, it is not generally considered a reportable illness in the U.S. health system. However, health officials track illnesses on cruise ships and thereby are able to track and report norovirus more quickly on a cruise ship than on land. In most cases of norovirus reported on cruise ships, the CDC has determined that the increased incidents of norovirus were sourced from passengers bringing the illness on board and transmitting it through direct or indirect contact - not from food or water sources.

It is estimated by the CDC that 23 million Americans contract norovirus every year, or one in every 12 people. Out of the approximately 8.5 million passengers taking a cruise out of a U.S. port annually, less than one percent (one in every 3,600 people) has actually been affected by norovirus.

Through thorough and regular inspections, the CDC ensures that cruise ships operating from U.S. ports have superior food handling and sanitary practices on board the ships. The chief of the CDC Vessel Sanitation program has said that the standard by which cruise ships are held for sanitation is the highest in the world.

What do cruise lines do to prevent illness from spreading?
Cruise lines wish to provide an enjoyable vacation and recognize that one ill passenger is one too many. Each CLIA member cruise line has an outbreak prevention and response plan to address gastrointestinal illness. The most effective means of preventing the spread of the virus, based on the cruise lines' experience, include:

• An aggressive communications effort on board ships encourages passengers to thoroughly wash their hands frequently to help avoid unknowingly spreading the virus. Washing one's hands regularly (every hour or two) is a very good way to reduce the spread of any contact virus such as norovirus.
• Aboard ship, staterooms and public areas are cleaned and disinfected daily.
• Cleaning procedures include the use of disinfectants on areas including, but not limited to: counters, bathroom surfaces, door handles, railings and grab bars, exercise equipment, video arcade equipment, vanities and TV remote controls.
• Cleaning measures go as far as disinfecting the Scrabble game tiles, poker chips and anything that a passenger might touch.
• Other measures include disposing of playing cards after each evening in the casino; not shaking hands at cocktail parties to reduce the risk of spreading the virus; and the elimination of all self-serve buffets (passengers point to the food they would like and staff will serve them).
• Areas where people are or have been sick are immediately and thoroughly cleaned, sanitized/disinfected.
• On turnaround days, extra crew may be brought on board to disinfect the ship with the CDC-recommended disinfectants from top to bottom before additional passengers board.
• Passengers with obvious symptoms of illness upon embarkation may be refused boarding.
• To avoid the risk of spreading the virus, passengers who experience symptoms are sometimes asked to remain in their cabins and could be asked to disembark the ship at the next available port. This procedure is endorsed by the CDC.
• All crew who have norovirus symptoms may be confined to their quarters or transferred off the ship.

What can passengers to do protect themselves from norovirus and to stay healthy in general while on board?
The CDC and cruise lines cannot emphasize hand washing enough. The CDC provides the following information in their Cruising Tips.

1. Wash your hands!

• Before and after eating and/or smoking.
• After touching your face and/or going to the bathroom.
• When your hands are dirty.
  Learn more about handwashing techniques.

2. Leave the area if you see someone get sick (vomiting or diarrhea).
Report to cruise staff, if not already notified. You could become sick if you ingest contaminated particles that travel through the air.

3. Take care of yourself.
Get plenty of rest and drink lots of water. Resting helps rebuild your immune system. Drinking water helps prevents dehydration.

4. Be considerate of other people's health.
If you're ill before taking a cruise, call the cruise line to determine if there are alternative cruising options.

Sanitation procedures and programs
Cruise ships calling on U.S. ports on a foreign itinerary that carry 13 or more passengers are inspected twice a year through the Vessel Sanitation Program, which was started in early 1970s. Cruise ships are routinely thoroughly cleaned and adhere to strict sanitation standards. In general, the lower the score, the lower the level of sanitation; however, a low score does not necessarily imply an imminent risk for gastrointestinal disease. Since the program began, the number of disease outbreaks on ships has declined despite significant growth in the number of ships sailing and the number of passengers carried.

In nearly every case of norovirus, the CDC traced the virus to passengers bringing it on board and transmitting the illness. So, while the ships are cleaned and sanitized, the arrival of new, susceptible or affected passengers every one or two weeks on cruise ships provides an opportunity for the transmission of norovirus during successive cruises.

Read more about the Vessel Sanitation Program.

What are cruise lines required to do through the CDC's Vessel Sanitation Program?
A reportable case of gastrointestinal illness is defined as: three or more episodes of loose stools in 24 hours or vomiting and one additional symptom including one or more episodes of loose stools in a 24-hour period, or abdominal cramps, or headache, or muscle aches, or fever; reported by a passenger or crewmember to the master of the ship or the ship's medical staff during an international cruise that includes a U.S. port.

In addition to antibiotics, medications for symptomatic treatment of nausea or gastrointestinal illness are considered controlled substances on board ships and should be distributed only by the medical staff to ensure the maintenance of an optimal surveillance system. Passengers and crewmembers that are given these medications but not medical attention are also required to be included in the gastrointestinal illness surveillance report.