Food poisoning: the worst souvenir

Dean Cliver and his wife, Carolyn, were enjoying a beef and vegetable pie that their host, a physician in Nancy, France, had served them for dinner when they got a little surprise.

After Cliver told his host how delicious it was, the doctor told him the pie was from a local butcher shop that had a reputation for products tainted by salmonella.

“At that point there was no turning back,” Cliver said. “I had almost finished my first helping.” Tempting fate, he had a second.

It was a particularly painful episode for Cliver, a professor of food safety at UC Davis -- and it would become even more so.

Two days later the Clivers were at a London stopover, where, to economize, they had chosen a hotel room with a shared bath. Big mistake. The couple spent a long evening running back and forth to the bathroom.

The Clivers’ memorable-for-all-the-wrong-reasons vacation meal illustrates the potency of food-borne illnesses -- salmonella can strike from 12 to 72 hours or even days after exposure -- and nearly every traveler’s susceptibility to such bugs.

Summer is the so-called high season for food-borne illness, commonly known as food poisoning, which is caused by bacteria or viruses. About 76 million cases of food-borne illness occur in the United States each year, according to statistics from the federal Centers for Disease Control and Prevention. Up to half of the 50 million people who travel from the industrialized world to developing countries each year get traveler’s diarrhea from consuming tainted food or drink, according to data from the National Institutes of Health.

The ways that bugs contaminate food include improper food handling and poor sanitation in the production of the food.

One such illness results when the food contains a toxin, such as the one that causes botulism, Cliver said. Infections occur when you eat food contaminated with an organism, such as the salmonella bacterium, and the organism multiplies in your body. (Poultry and eggs are common causes of salmonella illness, called salmonellosis.)

As researchers are discovering, even travelers who follow precautions can get sick. When Dr. David Shlim, now a travel medicine specialist in Jackson Hole, Wyo., worked at a clinic in Nepal, he said he saw more than 20,000 travelers who had diarrhea.

He would dispense the usual advice about how to avoid it, telling patients to peel fruits and avoid tap water and raw vegetables, but he realized it wasn’t foolproof. “Even if people do all this, they can still get sick,” he said.

Drug resistance is another problem. The standard antibiotics used to treat traveler’s diarrhea, such as Cipro (ciprofloxacin hydrochloride), are meeting resistance in Southeast Asia and India, said Dr. Charles Ericsson, director of the Travel Medicine Clinic at the University of Texas-Houston Medical School. The ready availability of those drugs -- over the counter in some countries -- and their misapplication may be partly to blame.

An alternative sometimes prescribed is Zithromax (azithromycin). A new drug being studied, rifaximin, may be on the U.S. market by 2004, said Dan Lundberg, a spokesman for Salix Pharmaceuticals in Raleigh, N.C. A manufacturer-sponsored study, reported this month at the International Society of Travel Medicine meeting, found that the drug treats traveler’s diarrhea without producing bacterial resistance. Because most of the drug remains in the gut, fighting the bacteria rather than being absorbed systemically, fewer side effects such as nausea are reported than with other antibiotics, the manufacturer’s study said.

Some people, of course, seem to have a cast-iron stomach, able to eat spoiled food and remain unscathed. “Emerging data suggest there may be a genetic aspect to the cast-iron stomach,” Ericsson says. In his research, he has found that some people do not mount what experts call an “inflammatory response” to the offending organism and thus don’t get as sick.

But even cast-iron-stomach types should follow some precautions, experts say. Among them:

* In areas where sanitation is questionable, choose cooked fruits and vegetables instead of raw, Cliver advised. “There’s this increasing insistence on [eating] raw fruits and vegetables, with some of our pseudo-nutritionists who say if it isn’t raw, it isn’t good. There is no nutritional superiority to raw food. If you have an orange or something you can peel yourself, you are probably OK. But raw broccoli florets, those would probably be a problem” in areas with substandard hygiene.

* If in doubt, don’t eat it. Mayonnaise and dishes that include it, such as tuna or potato salad, have a reputation for causing problems, though many other foods can make you just as sick. (Mayonnaise is an ideal medium for bacteria because it’s moist.)

Any food that is contaminated and stays warm acts as an excellent culture medium, so the bacteria have a chance to multiply, giving you a bigger dose, Ericsson said.

* Remember that certain foods may be riskier than others. “In Nepal, we showed that eating ... casseroles or any food that is cooked earlier in the day and reheated proved to be associated as a risk factor for diarrhea,” Shlim said. (He suspected the casseroles probably sat out at room temperature long enough to allow organisms to thrive. Leftovers and prepared foods should be refrigerated within two hours, according to the National Institutes of Health.)

* Consider packing a treatment kit with a prescription antibiotic and some over-the-counter diarrheal medicine. Ask your doctor for specifics about dose and timing.

Healthy Traveler appears twice a month. Kathleen Doheny can be reached at kathleendoheny@

earthlink.net.