Cruise Control: Reducing Your Risk for Noroviruses
The Centers for Disease Control and Prevention (CDC) and the Cruise Lines International Association (CLIA) have been working together for decades to ensure your cruising experience is a safe, healthy, and enjoyable one. So, you may wonder why there are still disease outbreaks. Sources in the cruising industry blame it on the increased popularity of cruising. More people, more ships, more destinations, and less vessel “downtime” between trips can set the stage for a norovirus outbreak. But, that does not mean your ship needs to sail without you. Here are some tips for a safe and healthy cruising adventure.
Noroviruses are actually quite common, and are rarely deadly or life-threatening. The original norovirus strain discovered was named after an outbreak of gastroenteritis in a school in Norwalk, Ohio in 1968. You may be familiar with the term Norwalk virus or Norwalk-like virus. They are all considered noroviruses. The gastroenteritis caused by noroviruses are mild, self-limiting, but highly contagious diseases characterized by nausea, vomiting, diarrhea, and abdominal pain. Muscle aches and low-grade fever may also occur. Symptoms of noroviruses typically develop within 1-2 days of exposure and may last from 1 day to 1 week.
Water is a common source of outbreaks of the noroviruses. This may include water from municipal supplies, wells, recreational lakes, swimming pools, and water stored aboard cruise ships. The noroviruses are transmitted by the fecal-oral route, directly from person-to-person, through ingestion of contaminated water and foods, or through contact with a surface that has been contaminated.
Shellfish are the foods often implicated in norovirus outbreaks. Ingestion of raw or insufficiently steamed clams and oysters that were harvested in sewage-polluted water poses a high risk of infection. Foods other than shellfish can be contaminated when washed in water that contains the virus or by food handlers carrying the virus.
The Cruise Connection
The CDC and the cruise ship industry worked together to form a Vessel Sanitation Program (VSP). This program helps prevent and control the transmission and spread of gastrointestinal illnesses on cruise ships.
You may still be wondering about the connection to disease outbreaks on cruises. Close living quarters may increase the amount of person to person contact. New passengers arriving on the ship can also transmit the virus to existing passengers and crew members.
The CDC performs unannounced ship inspections which results in outbreaks being discovered and reported. Sometimes this can inflate outbreak numbers to make it look like cruise ships have more infections than on land.
The good news is that the VSP found a decrease in sanitation violations from 1990-2005. This means the cruise ship industry is working hard to keep things safe for travelers.
Reducing Your Risk of Infection
There are some measures you can take to reduce your risk of getting sick during your cruise.
Before the Trip
- Check the history of the cruise ship you are planning to take (for example, any previous outbreaks or failed inspections).
- If you have a chronic illness, ask your doctor if it is safe for you to go on a cruise.
- Check the Travelers Health page at the CDC website for updated travel notices. These notices inform travelers of disease outbreaks and their locations.
- Wash your hands thoroughly and often with soap and warm water, particularly before eating, preparing food, and after using the bathroom.
- Avoid other passengers who are ill.
- Avoid foods that may have been washed in contaminated water.
- Go to the infirmary if you have symptoms of an infection.
If You Get Sick
Seek medical attention right away. All cases of suspected noroviruses should be reported to the ship’s medical staff.
The most common complication of noroviruses is dehydration. Drink plenty of bottled water, clear liquids such as flat ginger ale, fruit juices, or decaffeinated teas or broth made from safe drinking water.
If you become extremely sick and dehydrated, you may need a special rehydration solution. This is best obtained from the ship’s medical staff, but it may be available in a dry mix, which can be purchased in a drug store before you leave home. (Ask your doctor about this before you go). Severe cases may require a hospital stay so that you can receive hydration and electrolytes through an IV.
Get as much rest as you can and stay calm. Gastroenteritis is an uncomfortable illness that will usually resolve itself within a few days. If you become ill onboard, you may be isolated from the rest of the passengers or you may be asked to disembark at the next port. This is done for your own protection, as well as the protection of the other passengers on the ship. It may not be the end to your vacation that you had envisioned, but it will be in everyone's best interest. Remember, new ships sail every day. Once you are feeling better, you may be able to get on the next one!
Centers for Disease Control and Prevention
Cruise Lines International Association
Communicable Disease Control Unit—Manitoba Health
Bert F, Scaioli G, et al. Norovirus outbreaks on commercial cruise ships: a systematic review and new targets for the public health agenda. Food Environ Virol. 2014;6(2):67-74.
Cramer EH, Blanton CJ, et al. Shipshape: Sanitation inspections on cruise ships, 1990-2005, Vessel Sanitation Program, Centers for Disease Control and Prevention. J Environ Health. 2008;70(7):15-21.
Cruising tips. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/nceh/vsp/pub/CruisingTips/cruisingtips.htm. Updated January 16, 2014. Accessed January 4, 2017.
Facts about noroviruses on cruise ships. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/nceh/vsp/pub/Norovirus/Norovirus.htm. Updated August 5, 2013. Accessed January 4, 2017.
Norvirus infection. EBSCO DynaMed Plus website. Available at:http://www.dynamed.com/topics/dmp~AN~T114466/Norovirus-infection. Updated April 20, 2016. Accessed January 4, 2017.
Traveler's health. Centers for Disease Control and Prevention website. Available at: http://wwwnc.cdc.gov/travel. Accessed January 4, 2017.
Vessel sanitation program. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/nceh/vsp/default.htm. Updated September 6, 2016. Accessed January 4, 2017.
Last reviewed January 2017 by Michael Woods, MD Last Updated: 1/7/2015