Food's bad bugs.

Dangerous microbes may be lurking in your favorite foods. Should we use low doses of radiation to kill them?

Last July, 12-year-old Amanda Berry felt awful, but she didn't know why. She was suddenly racked with stomach cramps and bloody diarrhea. Was it a severe flu? Some weird disease? Amanda got so sick her parents rushed her to a Denver, Colorado hospital emergency room.

Medical technicians performed tests--and soon uncovered the strange cause for her illness. Berry was infected with E. coli 0157:H7, a dangerous strain of bacteria, or single-celled organism. And Amanda wasn't alone. At the same time 16 others in Colorado had also contracted E. coli infections.

Public health officials pieced together clues until they discovered a common link: Every one of the people infected, including Berry, had just chowed down on a hamburger! Like detectives hot on the trail, officials traced the ground beef to a single meat-processing plant in Columbus, Nebraska, owned by the wholesale meat company Hudson Foods. What followed became the biggest food recall in U.S. history--25 million pounds of hamburger meal were yanked off supermarket shelves and fast-food grills within days.

Amanda Berry spent nearly two weeks in the hospital. She's one of 20,000 people in the U.S. infected by E. coli last year, according to the U.S. Centers for Disease Control in Atlanta, Georgia Of those, 250 people are dead.

PROWLING PATHOGENS

Many Americans now think twice before biting into a burger. But avoiding E. coli isn't as simple as giving up ground beef. People have gotten sick from eating E. coli-infected lettuce, alfalfa sprouts, and apple cider.

And E. coli isn't the only pathogen, or disease-causing microbe, lurking in our food. Raspberries grown in Guatemala were the culprit in 2,300 illnesses over the last two years. The fruit was infected with a parasite (an often harmful organism that depends on other living things to survive) called Cyclospora. In 1994 a bacterium called Salmonella, which hides out in poultry, eggs, fruits, and veggies, made as many as 2 million Americans sick (see pathogen chart, p. 15). And the country's leading cause of foodborne illness is the Campylobacter bacterium, thought to infect up to 90 percent of all chickens. (A recent sampling in Minnesota supermarkets found 79 percent of chickens and 59 percent of turkeys with Campylobacter bacteria)

Each pathogen has its own method for sneaking into the food supply. For example, E. coli is released from some cows' intestines when accidentally nicked during the slaughtering process, explains James Brunton, a researcher at Toronto Hospital. (E. coli doesn't seem to make cows sick enough for anyone to notice.) Brunton thinks E. coli infects fresh fruit and vegetables when animal feces are used as fertilizer and spread on soil planted with crops, or when crops are sprayed with infected water.

Once inside the human digestive tract, E. coli and other pathogens release toxins, or poisons, that cause symptoms like cramps, nausea, bloody diarrhea (caused by bleeding in the large intestine), headaches, and fever. Most people recover from E. coli in 10 days, but some experience kidney failure--which can lead to death.

How to prevent such pathogens from ending up in your guts? U.S. government inspectors try to ensure our food supply stays safe. They "sniff and poke" many animal carcasses to check for spoilage. But even an eagle-eyed inspector can miss food infected with E. coli or Salmonella, which don't emit unusual odors and are too tiny to be seen without microscopes. Inspectors do send some food samples to a lab for analysis. But it's impossible to check every burger or alfalfa sprout. So, at home, it's vital to rinse fruits and veggies well, and to cook all meat. thoroughly.

ZAPPING BACTERIA

Health officials like Minnesota's Michael Osterholm advocate exposing meat, poultry, and vegetables to low doses of radiation, or high-energy atomic particles. Radiation destroys microbes' ability to reproduce. But it has a major downside--it also destroys some radiation-sensitive vitamins (A, B, C, E, and K) in food.

The process is called irradiation, and the U.S. Food and Drug Administration (FDA) has approved it for foods such as poultry, grains, potatoes, and fresh fruit, says Laura Tarantino, an FDA irradiation expert. Beef soon may be added to the list. The process sounds foolproof: One quick zap and forget about dangerous microbes. Not to mention that food stays fresher up to four times longer than usual.

But many shoppers think the process of irradiation sounds unappetizing. So the process has not found wide use yet in the U.S. Some consumers worry that radiation aimed at microbes could turn their favorite foods into cancer risks. Not so, says Tarantino. The doses of radiation used to kill microbes are too low to make food radioactive.

But other worries remain. "Exposing foods to radiation is known to take away food's nutritional "quality," says Michael Colby, director of Food and Water, Inc., a national food safety and environmental organization.

The FDA's Tarantino counters that irradiation can "kill" some vitamins in food--but not enough to deplete food of valuable nutrients. FDA studies show no real health risks from eating irradiated food. And at least a few people are happy to chow down on "zapped meat"--irradiated steaks are a favorite with astronauts aboard space shuttle flights.

Colby believes a better answer is cleaning up water supplies, farms and food-processing facilities--so the microbes don't get into our food in the first place. While scientists, the FDA, and consumer advocates duke it out, you can reduce your risk of getting sick by carefully handling and cooking foods that these pathogens may call home. (See our miniposter and food safety sidebar.)

PATHOGEN FACT SHEET

Pathogen          Type            Foods Affected   Major U.S.
                                                   Outbreaks

E. coli 0157:H7   bacteria        hamburger,       1997: 25 million
                                  lettuce,         pounds of
                                  apple cider,     hamburger are
                                  alfalfa          recalled after
                                  sprouts          16 people fall
                                                   ill in Colorado.
                                                   1996: More than
                                                   70 people get
                                                   sick after
                                                   drinking
                                                   infected apple
                                                   cider. 1993: Two
                                                   people die and
                                                   600 fall ill
                                                   after eating
                                                   infected
                                                   hamburgers from
                                                   a fast-food
                                                   chain.

Cylospora         single-celled   rapberries       1996: About a
cayetanensis      parasite                         thousand people
                                                   in 20 states
                                                   suffer diarrhea,
                                                   cramps, and
                                                   fever.

Hepatitis A       virus           strawberries     1997: More than
                                                   200 people
                                                   --including 100
                                                   kids--get sick
                                                   after eating
                                                   strawberries
                                                   from Mexico.

Salmonella        bacteria        eggs, poultry,   1994: Infected
                                  fresh fruits     eggs used in
                                  and vegetables   ice cream cause
                                                   600 illnesses.
                                                   1991: Sliced
                                                   cantaloupe from
                                                   salad bars makes
                                                   400 people in
                                                   23 states sick.