Salmonella from cantaloupe. Hepatitis A from strawberries. Cryptosporidium from scallions. Shigella from parsley. The list of disease-causing microbes in fruits and vegetables is almost as varied as our supply of fresh produce. A few key examples:
Lettuce
In 1996, Rita Bernstein of Wilton, Connecticut, served mixed, pre-washed lettuce to her daughter Haylee, then three years old. That salad almost blinded the child.
The lettuce—which sickened 60 others in New York, Illinois, and Connecticut—was contaminated with E. coli O157:H7. After visiting the California farm where it was grown, investigators weren’t surprised.
The workers who picked the lettuce washed it in water that came from wells near cattle pastures, and no one had added chlorine to the water to kill any bacteria.
“They picked the lettuce and dunked it in a bath of cold water—called a hydrocooler—to cool it down quickly,” says the CDC’s Robert Tauxe. “In a big, centralized food supply, that’s how one dirty hand or manure run-off on a few heads of lettuce spreads to thousands and thousands of heads going all over the country. If the bath is contaminated, it spreads to all of the produce.”
California now makes sure that only clean water is used in the hydrocoolers on its produce farms, says Tauxe. But there was recently an outbreak of another bacteria, Shigella, in parsley from a farm in Baja California, Mexico.
“The hydrocooler was using water from the local village water supply, which wasn’t chlorinated,” he explains. “In fact, the farmworkers got bottled water as part of their contract so they wouldn’t have to drink the local water.”
Says Tauxe: “If the food industry is going to wash produce that I’m going to eat without cooking, I want them to use water that I would drink.”
Berries
“I got ferociously ill,” Barney Savage, a 32-year-old administrator at York University, told the Toronto Star in April.
The previous May, Savage and five friends had eaten a raspberry dessert at a restaurant. Within a week, all six were statistics in the 1998 Canadian Cyclospora outbreak in which 200 people became ill.
Cyclospora is a microscopic parasite that invades the gut about a week after it’s ingested. It causes diarrhea, extreme fatigue, cramps, and nausea.
The first big Cyclospora outbreak hit in 1996. At least 1,465 people in the U.S. and Canada got sick. It didn’t take long for investigators to finger Guatemalan raspberries, which probably picked up the bug from contaminated water.
After another Cyclospora outbreak in 1997 in which 1,000 people became ill after eating raspberries from Guatemala, the U.S. cut off raspberry imports. Canada didn’t. In 1998, the year Barney Savage became ill, no Americans got sick. But some 200 Canadians did.
In 1999, the U.S. reopened raspberry imports from a few select Guatemalen farms. Health authorities are hoping there are no new illnesses.
Sprouts
In the first large U.S. outbreak (which also hit Finland), 242 cases of Salmonella poisoning were reported to health authorities in 1995. Officials estimate that between 5,000 and 24,000 people got sick.
All the seeds in that outbreak were traced to a shipper in the Netherlands. In its warehouse, investigators found rodents and birds (which could have spread the bacteria) and debris-filled bags of seeds imported from Italy, Hungary, or Pakistan.
“Bacteria and seeds like precisely the same conditions—warmth and moisture—to grow well,” explains the FDA’s Morris Potter. It has become clear that there is no way to guarantee the safety of sprouts.
“Consumers need to understand that, at this time, the best way to control this risk is not to eat raw sprouts,” said FDA Commissioner Jane E. Henney in July.
Before you cut cantaloupes or other melons, scrub the skins with water and a brush. (If you don’t, cutting them could transfer pathogens from the rind to the flesh.)