Shaking hands may be the conventional greeting for landlubbers, but on the high seas, the "forearm tap" has become popular. This greeting of knocking elbows together instead of shaking hands was encouraged by a number of cruise lines to raise awareness of the importance of personal hygiene on board ship, according to a representative for Carnival Cruise Lines.
Poor personal hygiene is the likely cause of gastrointestinal illness (gastroenteritis) on cruise ships, according to the Centers for Disease Control and Prevention (CDC). The CDC investigated 22 reports of gastroenteritis outbreaks aboard 18 cruise ships from Jan. 1, 2002, through Dec. 31, 2002. Of the 22 outbreaks, three were blamed on bacteria and seven could not be traced with certainty, but the remaining 12 were confirmed to be associated with noroviruses--a group of viruses that cause gastroenteritis, also known as Norwalk-like viruses.
Symptoms of norovirus infection include nausea, vomiting, diarrhea and stomach cramping that can last from 12 to 60 hours. The symptoms usually begin 24 to 48 hours after a virus is ingested. Although people may feel very ill and vomit frequently, norovirus infections are not considered serious in most individuals. But they may become serious in the very young, older people, and in those with weakened immune systems.
Noroviruses are found in the stool or vomit of infected people, and infection can spread in several ways:
- Eating food or drinking liquids that are contaminated with the virus
- Touching contaminated surfaces or objects and then placing your hands in or near your mouth
- Having direct contact with another person who is infected and showing symptoms (for example, sharing foods or eating utensils).
Traveler's diarrhea from bacterial infections can also be the cause of the vacationer's gastrointestinal woes. Bacterial infections usually go away over time without treatment, but doctors may prescribe antibiotics to treat some and shorten the duration of the diarrhea. No medications are approved for preventing bacterial infection, nor are there medications that prevent or treat noroviruses. For more, please read the Traveler's Diarrhea article.
Advice for Travelers
Frequent and thorough hand washing with warm, soapy water is the best prevention against gastroenteritis and other gastrointestinal illnesses. Travelers who don't have ready access to soap and water may want to carry along a hand gel sanitizer, found in most supermarkets and drugstores.
When traveling, choose foods and beverages carefully. Foods should be thoroughly cooked and served hot. Poor sanitation in some countries may lead to contaminated food and drink, which are the major sources of stomach or intestinal illness while traveling, according to the CDC. Just about any food can become contaminated if handled improperly, but items of particular concern include raw meat, raw seafood, green salads, and raw sprouts. "In some countries, it's wise to steer clear of street food vendors, especially if they serve fresh-cut fruits," says Jackson, who advocates purchasing fruits whole, peeling them and cutting them up yourself.
Travelers should avoid unpasteurized milk or products made with unpasteurized milk, unpasteurized juices and ciders. Beverages that may be safer than tap water in some countries are hot beverages, such as coffee or tea made with boiled water, canned or bottled carbonated beverages, and beer and wine. Avoid ice made with tap water. Water on the surface of a beverage can or bottle may be contaminated, so wipe clean and dry the area of the container that will touch your mouth. For more, please read the MedicineNet.com Traveler's Tips for Safe Water and Traveler's Tips for Safe Eating articles.
The Cruise Ship Connection
CDC investigators believe that most of the recent norovirus infections on cruise ships were spread person-to-person through hand-to-mouth activity. "We suspect that people are probably coming on board with the virus," says Dave Forney, chief of the CDC's Vessel Sanitation Program. "On a cruise ship, people are out and about in very public areas, and so we have this depositing of the virus on various surfaces that then would be easily picked up by others."
Forney advises cruisers who are ill to avoid contact with other individuals and to report to the ship's medical facility. Unfortunately, many of them don't want to be told to stay in their cabins, adds Forney, so passengers spreading the virus around the ship are contributing to the ongoing problem.
Outbreaks on cruise ships have gained media attention, but an estimated 60 percent to 80 percent of all outbreaks of severe gastroenteritis occur on land, says the CDC. Norovirus infection is the most common cause of non-bacterial gastrointestinal illness in the United States; about 23 million cases of severe gastroenteritis a year are due to noroviruses. Noroviruses may be found in areas where people congregate together for days at a time, such as in schools, hotels, camps, nursing homes, and hospitals. Gastroenteritis is not a reportable illness in the United States except on cruise ships, so the public may be more aware of the shipboard incidences, says Forney.
By law, cruise ships that enter a U.S. port from a foreign port are required to report to the CDC, 24 hours prior to arrival, the number of passengers and crew on board who go to the ship's medical facility with gastrointestinal illness, even if the number is zero, says Forney. Having 3 percent or more of either passengers or crew reported with a gastrointestinal illness is considered an outbreak and cause for investigation.
Travelers shouldn't shun cruises, says Forney. "It is perfectly safe to go on cruise ships. The standard by which they are held for sanitation is the highest in the world." Extensive cleaning and disinfecting were carried out on ships immediately following reports of illness, Forney adds. And cruise lines continue to scrub and sanitize public areas of their ships, especially frequently touched surfaces such as handrails, elevator buttons, and even poker chips.
For more information, please visit the following MedicineNet.com areas:Food and Drug Administration (http://www.fda.gov/).