WEDNESDAY, Aug. 14, 2002 (HealthDayNews) -- It's not absolutely necessary to travel overseas to get an exotic disease -- think West Nile virus.
However, it helps.
Some 20 percent to 70 percent of the 50 million people who travel from industrialized countries to developing nations each year report some illness associated with their travel, reports an article in tomorrow's issue of The New England Journal of Medicine.
Most of the illnesses are mild. However, 1 percent to 5 percent of travelers become sick enough to seek medical attention, 0.01 percent to 0.1 percent require evacuation from the country they are visiting, and one in 100,000 dies.
There are no hard statistics indicating that the number of people traveling overseas or those succumbing to disease is increasing, but experts suspect that's the case.
"According to the most recent Census, about 8 percent of U.S. residents traveled to developing countries each year. I suspect that it's higher than in the 1950s and 1960s," says Dr. Edward T. Ryan, lead author of the article and director of the Tropical and Geographic Medicine Center at Massachusetts General Hospital in Boston.
There may also be more illness waiting for the unsuspecting tourist.
"I would say in general there's more disease out there," says Dr. Richard Witzig, an assistant professor of medicine in infectious diseases at Tulane University School of Medicine. "Malaria has made a comeback. Dengue fever has made a comeback."
Two groups seem to be particularly vulnerable: adventure travelers and people visiting families and friends. The Centers for Disease Control and Prevention (CDC) even has a name for this second group: "VFRs" or "Visiting Friends and Relatives."
There are a number of explanations for why they get sick while overseas: They probably don't see their doctor before they go, they typically don't stay in hotels and veer away from tourist routes, they stay for longer periods of time, or they may not fully appreciate the risk of disease because they used to live in the place they are visiting.
Malaria is a case in point. Legions of people have gone back to their country of origin thinking they were immune to this potentially fatal disease because they had it as a child, only to fall ill during a vacation.
"You can develop immunity to malaria, but only when you're repetitively exposed, and two to three years after being out of the endemic zone, your risk goes back to being what it was when you were a baby," Ryan explains.
The most common medical complaint among international travelers is still intestinal problems. Some 10 percent to 40 percent of overseas travelers will develop diarrhea, Ryan says. Following close behind are an array of dermatological conditions, from insect bites to allergic reactions to sunburn. Next are respiratory infections, often reactions to air pollution.
The one to watch out for is fever. "That's the one we have the most respect for," Ryan says. Malaria leads this list.
According to the article, about 3 percent of people traveling internationally for short periods of time report fever either while still abroad or after they return. If you develop a fever, you should see your doctor immediately.
In fact, anyone who has been overseas and develops symptoms of any kind should see their internist, Ryan advises. "You should have a very low threshold for seeing your doctor," he says.
You should also see your doctor before you visit a developing country, but make sure you leave enough time to get all the necessary immunizations and pills.
"The most common error is seeing your physician a few days before you leave," Witzig says. "Then you're not able to get the full amount of vaccinations you may need. If you're going on any sort of trip where you're going to have substantial exposure to the local environment and local water or fruit, visit your physician about a month in advance."
Various precautions can lower your risk of getting sick, including vaccinations, pills (for malaria), and even antibiotics in case you develop intestinal problems.
While you're abroad, follow some common-sense procedures. Don't eat anything from street vendors, steer clear of raw fruits and vegetables, and try to order cooked food as often as possible.
The main cause of diarrhea is contaminated food, not contaminated water, says Dr. Herbert L. DuPont, chief of internal
medicine and director of travel medicine at St. Luke's Episcopal Hospital, and clinical professor of medicine at Baylor University and the University of Texas, all in Houston.
"The two words that spell danger are 'moisture' and 'room temperature,' " DuPont says. "Anything wet at room temperature is
deadly." Foods that are safe include those with a high sugar content (such as jams and jellies), those that are dry (bread), those
with a high acid content (citrus fruits) and anything steaming hot.
DuPont has been known to take a thermometer into restaurants while abroad to test the temperature of the food. Anything
below 60 degrees Celsius is sent back to the kitchen.
To prevent malaria, DuPont recommends the same arsenal he travels with: insect repellant for your skin (do it every day
regardless of whether you think you're going out); permethrin for your clothes; and netting for your bed as well as screens on
the windows. DuPont actually patrols his hotel room for mosquitoes about two hours before he's supposed to check in. If he
finds two or more of the little critters, he "napalms" the room with Raid and lets it sit for three hours.
Also, do some advance research about your destination and read the local newspapers, which often report about an outbreak well before the local government.
"I've read local newspapers in South America and picked up valuable information, such as where yellow fever or malaria outbreaks were occurring," Witzig says. "Often it's not information that public health people are disseminating."
Most of all, enjoy your trip, the doctors say.
"It's a wonderful world but recognize that there are some risks associated [with travel]. And you can lower your risks by checking with your doctor before you go and if something's wrong when you get back," Ryan says.
What To Do
For more information on travel and health, visit the Centers for Disease Control and Prevention (CDC). Two sites are collecting surveillance information on infectious diseases: the European Network on Imported Infectious Disease Surveillance and GeoSentinel, a joint project between the CDC and the International Society of Travel Medicine.
