THE STRAWBERRY SICKNESS

By Christine Gorman

It feels like the worst case of Montezuma's revenge you've ever had. Stomach cramps. Vomiting. Diarrhea that persists for days, if not weeks. The culprit? It could be raw vegetables, a fruit salad or those juicy fresh strawberries you just ate. At least that's what health officials were saying last week, when they announced that over the past two months a few hundred people in the U.S. and Canada have been stricken with a new and mysterious intestinal infection. So far, no deaths have been reported, although a few people have been hospitalized for severe dehydration. But what baffles the experts is how a rare illness that was once seen only in places like Peru and Nepal has managed to spread so quickly in such far-flung cities as New York, Houston, Palm Beach, Florida, and Toronto.

The microbe that is responsible--Cyclospora cayetanensis--doesn't come from the relatively familiar world of viruses and bacteria. Instead, it hails from the strange realm of protozoa--single-celled organisms that have complex, multistep life cycles and are big enough to be seen under an ordinary microscope. Protozoa are usually found in ponds and moist, humid places like garden soil. There are many different types of protozoa, but this particular strain was not identified until the early 1990s.

Health experts suspect that Cyclospora may have piggybacked a ride into North America in the intestines of world travelers. But that doesn't explain how it managed to spread beyond those initial contacts. Doctors have traced 26 of 61 confirmed cases in Houston to two gatherings at which strawberries were served. "Those who got ill ate strawberries, and those who didn't get sick didn't recall eating any strawberries," says Dr. Kate Hendricks of the Texas department of health. Investigators traced that fruit back to a handful of California farms but so far haven't turned up any tainted strawberries there. They point out that contamination could have occurred anywhere on the food chain--from pickers to wholesalers to retailers to cooks.

Until they can figure out what's going on, health officials are advising consumers to wash fresh fruit and vegetables especially thoroughly before eating them. That should help dislodge the protozoa, although it's no guarantee it will. People with weakened immune systems--AIDS patients and anyone undergoing chemotherapy--are advised to avoid strawberries altogether. Children and the elderly suffering intense diarrhea should be watched with particular care; they can quickly become dangerously dehydrated.

Fortunately, the immune systems of most healthy adults are strong enough to successfully eliminate Cyclospora infections after several weeks. But doctors can shorten the length of the illness considerably by treating patients with strong antibiotics. So if you have diarrhea that persists for more than a couple of days or that recurs after a few days, see your doctor as soon as possible. And don't forget to wash those strawberries!

--By Christine Gorman. Reported by Deborah Fowler/Houston and Christine Sadlowski/New York

With reporting by DEBORAH FOWLER/HOUSTON AND CHRISTINE SADLOWSKI/NEW YORK