"Street food is a notorious source of contamination," says Dr. Brian Terry, director of the Healthy Traveler Clinic in Pasadena, California. Dining à la cart is an especially bad idea when you consider that, according to the CDC, up to 50 percent of travelers will develop diarrhea while on vacation in a "high-risk" area—Mexico, some Carribbean islands, Latin America, Africa, the Middle East, and parts of Asia. Children are extra vulnerable because they haven’t developed as much immunity to pathogens as adults have. Bacteria, like E. coli, are responsible for 85 percent of cases of traveler’s diarrhea, but protozoa and viruses can also sicken you. Poor hygiene is usually to blame—vendors often don’t have access to the hot, soapy water necessary to kill germs on their hands—but microscopic pests can also seep into fruits and vegetables as they grow. "In developing countries," Dr. Terry explains, "farms are often fertilized with human excrement" (night soil). Beware of raw vegetables, like cilantro in tacos or tomatoes in salsa; fruit (and possibly water) in smoothies; and foods cooked and allowed to cool, such as meat pies—bacteria can multiply rapidly in the warmth and turn those goodies toxic.
Jim Leff, cofounder of chowhound.com, a Web site for adventurous eaters, has munched on street fare across 22 countries, from fried whole apples in Switzerland to grilled baby octopus in Queens, New York, and never gotten seriously ill. His advice: "Eat at popular stands patronized by regular shoppers." Established street chefs, he claims, have found sources of clean water for cooking and hand washing. Dr. Bradley Connor, a gastroenterologist and medical director of Travel Health Services, in New York City, agrees that street food can be "pretty interesting," but points out that a line of customers is not insurance you won’t get sick: natives develop immunity to local germs. Better to follow some guidelines on where and what to eat. In general, says Dr. Connor, it’s less of a risk to indulge in North America, western Europe, Japan, and Singapore, where food prep is regulated. And stick to dishes served piping hot: "Bugs are tough little critters and can resist everything but heat," Dr. Terry says. If you want to try the fruits, go ahead, but peel them yourself. Breads and baked goods are usually safe, even if cool. So savor the yummy Dutch waffle and maybe even sugared churros in Mexico—they’re what you’ll remember about the trip.
The Bottom Line
Always keep Imodium in your toiletries kit. If you’re traveling to a high-risk area, pack the antibiotic Zithromax in case of tummy troubles and steer clear of all but just-cooked street fare too hot to be touched by bare hands. Elsewhere, choose your snacks sensibly—but try to sprinkle in some roadside culinary adventures along the way.