Columbus and his comrades brought diseases to America, and now other countries are getting their revenge.

"I probably just touched something and didn't wash my hands before I ate," says Peter D. Richards '01, who deferred his first year of college to travel to Egypt with his brother.

During this seven-month excursion, Richards fell ill with amebic dysentery, which is caused by a parasite and produces severe intestinal discomfort including chronic diarrhea. He was hospitalized there.

"After I got a 103.5 degree fever, I decided the drugs they gave me in Egypt didn't work and I flew back to New York and saw a tropical disease specialist," Richards said.

Although this sounds like a rare experience, in reality, Richards represents one of many travelers who have suffered similar health problems--like diarrhea and fever--while traveling outside the United States.

The Invisible Threat

While expeditions to Western Europe and other industrialized areas do not generally pose health risks to Americans, visits to "developing" nations make travelers be on the alert.

Diseases like malaria and yellow fever, which almost never occur in the U.S., are everyday occurrences in many underdeveloped countries where, because of poverty, standards of sanitation and public health are lacking.

Many Harvard students spend summers and semesters abroad, increasingly in developing countries. About 150 join study abroad programs in general each year, and an additional 25 work abroad with the Weissman program. Many other students participate in programs not run by the Office of Career Services (OCS), according to International Experience Office Director Jane Pavese.

There is such a high demand, in fact, that University Health Services (UHS) will soon publish a guide for students travelling abroad.

Pavese says all students embarking on a study or work abroad program are required to attend pre-departure meetings designed to educate them about health and safety in foreign countries.

Study/work abroad programs also require participants to have health insurance.

"Students need to be prepared," Pavese says.

According to OCS statistics, about 60 percent of the students in study abroad programs travel to Western Europe.

But less-developed areas like Latin America, parts of East Asia and Russia, pose more health risks for travelers, and are also popular travel destinations.

Samantha A. Goldstein '00 went to Chiapas, Mexico last year to do field research for her thesis.

Before she left, she "took all the pills and shots. Malaria, hepatitis A, typhoid, yellow fever."

"I was totally prepared," says Goldstein, who is also a Crimson executive. "But I got sick twice or three times because of the water. It is very hard to avoid water totally because, for instance, things might not be cooked appropriately."

Like Richards, Goldstein suffered some intestinal discomfort.

"If I could offer students advice on traveling," Goldstein says. "I would say before you go to a developing country, make sure you get the right shots, drink only bottled water and make sure your food's cooked."

Dan M. Hughes '01 experienced serious health problems while visiting Tunisia, in northern Africa.

During the summer of '98, Hughes worked as a writer for Let's Go travel guides, a line of publications that sends Harvard students to various locales and pays them to record their experiences.

Although he too took all the recommended shots and vaccines, about four weeks into his six-week trip, Hughes had lost 15 pounds and was feeling ill.

It turned out that Hughes had contracted a parasite that was severely affecting his health. In addition, he came down with a painful urinary tract infection.

Hughes says he developed both conditions in Tunisia, where he questioned the purity of even the bottled water he bought.

"There's no reason to think the vendors wouldn't just fill the bottles with tap water," Hughes says. "They just want to turn a profit."

Kaya R. Stone '00, publishing director of Let's Go, says the company pays for its researchers' shots and warns them to be careful of what they eat in developing countries.

Despite the precautions, Let's Go researchers have had serious cases of illness, according to Stone.

"Two years ago, one researcher got dengue fever in Burma," Stone says.

Dengue fever is spread by mosquitoes and causes high fevers, rashes and pain in different areas of the body. It usually lasts about a week.

He added that Let's Go researchers in Southeast Asia see getting sick as "inevitable" because of the difficulty of adjusting to the foreign environment.

But Latin America, Africa and Southeast Asia are not the only regions travelers need to watch out for.

Dunia S. Dickey '03 took a trip to Russia last summer and became sick while dining in Moscow.

"If you go to Russia, don't drink the water," Dickey says. "Americans can't handle the bacteria."

Dickey agreed with Goldstein on the importance of ensuring that all food is completely cooked and is relatively clean of harmful bacteria.

Germ Defense

Students planning to travel to nations in many parts of Africa, Asia and South America should consult a physician about getting fully immunized to infections common to that region, according to UHS director David S. Rosenthal '59.

But students' vigilance cannot end at a few shots.

"[In countries with poor sanitation] be very careful of water and things washed in water," Rosenthal says, referring to foreign countries where the water supply contains levels and types of bacteria different than in the U.S.

These bacteria can often make unaccustomed Americans sick, causing diarrhea and other ailments.

Worm infestations are also a problem for individuals who go barefoot or eat food that is not thoroughly cooked. Many worms can thrive in an individual's intestinal tract and significantly limit that person's nutritional intake.

Rosenthal says travelers should also be concerned about purchasing antibiotics in some developing nations.

Sometimes, he said, because of poor public health regulation, travelers are given incorrect doses of antibiotics. Improper doses are dangerous when they reduce the normal levels of bacteria in the body, which allows other bacteria to reproduce and cause harm.

"Some students developed aplastic anemia when they were given harmful antibiotics for minor illnesses," Rosenthal says, describing a severe case faulty antibiotic use abroad.

Aplastic anemia, which can be fatal, is a failure of the bone marrow to produce normal blood cells.

UHS, in its soon-to-be-released guidebook entitled Healthy Travel, recommends inoculations or oral vaccines against the following: poliomyelitis, tetanus, diphtheria, typhoid fever, viral hepatitis, pneumococcal bacteria, influenza and meningococcal bacteria. The new guide also recommends the updating of childhood inoculations against measles, mumps and rubella.

UHS deems protection against yellow fever necessary and, in fact, some countries require all travelers to show proof of immunization.

The Centers for Disease Control (CDC) also prints a guide for international travelers, which provides exhaustive details about health concerns abroad.

Alternatively, students can consult the CDC's Web site at www.cdc.gov/travel/#Geographic for regional information about diseases.

Harvard students planning to journey far afield should use the information from both the CDC and UHS, Rosenthal says.

"Always plan ahead for international travel," he adds.